AWS IAM Role

December 31, 2022 ~ Last updated on : July 21, 2023 ~ jayendrapatil ~ 34 Comments

AWS IAM Role

IAM role is very similar to a user, in that it is an identity with permission policies that determine what the identity can and cannot do in AWS.

IAM role is not intended to be uniquely associated with a particular user, group, or service and is intended to be assumable by anyone who needs it.
Role does not have any static credentials (password or access keys) associated with it and whoever assumes the role is provided with dynamic temporary credentials.

Role helps in access delegation to grant permissions to someone that allows access to resources that you control.
Roles can help to prevent accidental access to or modification of sensitive resources.
Modification of a Role can be done anytime and the changes are reflected across all the entities associated with the Role immediately.

IAM Role plays a very important role in the following scenarios
- Services like EC2 instances running an application that needs to access other AWS services.
- Cross-Account access – Allowing users from different AWS accounts to have access to AWS resources in a different account, instead of having to create users.
- Identity Providers & Federation
  - Company uses a Corporate Authentication mechanism and doesn’t want the User to authenticate twice or create duplicate users in AWS
  - Applications allowing login through external authentication mechanisms e.g. Amazon, Facebook, Google, etc

Role can be assumed by
- IAM user within the same AWS account
- IAM user from a different AWS account
- AWS services such as EC2, EMR to interact with other services
- An external user authenticated by an external identity provider (IdP) service that is compatible with SAML 2.0 or OpenID Connect (OIDC), or a custom-built identity broker.
Role involves defining two policies
- Trust policy
  - Trust policy defines – who can assume the role
  - Trust policy involves setting up a trust between the account that owns the resource (trusting account) and the account that owns the user that needs access to the resources (trusted account).
- Permissions policy
  - Permissions policy defines – what they can access
  - Permissions policy determines authorization, which grants the user of the role with the needed permissions to carry out the desired tasks on the resource

Federation is creating a trust relationship between an external Identity Provider (IdP) and AWS.
- Users can also sign in to an enterprise identity system that is compatible with SAML
- Users can sign in to a web identity provider, such as Login with Amazon, Facebook, Google, or any IdP that is compatible with OpenID connect (OIDC).
- When using OIDC and SAML 2.0 to configure a trust relationship between these external identity providers and AWS, the user is assigned to an IAM role and receives temporary credentials that enable the user to access AWS resources.
IAM Best Practice – Use roles for applications running on EC2 instances
IAM Best Practice – Delegate using roles instead of sharing credentials

AWS STS & Temporary Credentials

AWS Security Token Service – STS helps create and provide trusted users with temporary security credentials that control access to AWS resources
STS is a global service with a single endpoint https://sts.amazonaws.com
AWS STS API calls can be made either to a global endpoint or to one of the regional endpoints. Regional endpoint can help reduce latency and improve the performance of the API calls

Temporary Credentials are similar to long-term credentials except for
- are short-term and are regularly rotated.
- can be configured to last from a few minutes to several hours.
- do not have to be embedded or distributed.
- are not stored or attached to the User, but are generated dynamically and provided to the user as and when requested

AWS Service Roles

Some AWS services need to interact with other AWS services for e.g. EC2 interacting with S3, SQS, etc

Best practice is to assign these services with IAM roles instead of embedding or passing IAM user credentials directly into an instance, because distributing and rotating long-term credentials to multiple instances is challenging to manage and a potential security risk.
AWS automatically provides temporary security credentials for these services e.g. EC2 instance to use on behalf of its applications
Deleting a role or instance profile that is associated with a running EC2 instance will break any applications running on the instance

Complete Process Flow

Create an IAM role with services who would use it for e.g. EC2 as a trusted entity and define permission policies with the access the service needs
Associated a Role (actually an Instance profile) with the EC2 service when the instance is launched
Temporary security credentials are available on the instance and are automatically rotated before they expire so that a valid set is always available

Application can retrieve the temporary credentials either using the Instance metadata directly or through AWS SDK
Applications running on the EC2 instance can now use the permissions defined in the Role to access other AWS resources
Application, if caching the credentials, needs to make sure it uses the correct credentials before they expire

Instance Profile

An instance profile is a container for an IAM role that you can use to pass role information to an EC2 instance when the instance starts.
If a Role is created for EC2 instance or any other service that uses EC2 through AWS Management Console, AWS creates an Instance profile automatically with the same name as the Role. However, if the Role is created through CLI the instance profile needs to be created as well.
An instance profile can contain only one IAM role. However, a role can be included in multiple instance profiles.

Service-linked Roles

A service-linked role is a unique type of IAM role that is linked directly to an AWS service.
Service-linked roles are predefined by the service and include all the permissions that the service requires to call other AWS services on your behalf.
Service-linked roles appear in your IAM account and are owned by the service. An IAM administrator can view, but not edit the permissions for service-linked roles.

Cross-Account access Roles

IAM users can be granted permission to switch roles within the same AWS account or to roles defined in other AWS accounts that you own.
Roles can also be used to delegate permissions to IAM users from AWS accounts owned by Third parties
- You must explicitly grant the users permission to assume the role.
- Users must actively switch to the role using the AWS Management Console.
- Multi-factor authentication (MFA) protection can be enabled for the role so that only users who sign in with an MFA device can assume the role
However, only One set of permissions are applicable at a time. User who assumes a role temporarily gives up his or her own permissions and instead takes on the permissions of the role. When the user exits, or stops using the role, the original user permissions are restored.

Complete Process Flow

IAM Role - Cross Account Access

Trusting account creates an IAM Role with a
- Trust policy which defines the account (trusted account) as a principal who can access the resources and a
- Permissions policy to define what resources can the user in the trusted account access
Trusting account provides the Account ID and the Role name (or the ARN) to the trusted account
If the Trusting account is owned by Third Party it can optionally provide an External ID (recommended for additional security), required to uniquely identify the trusted account, which can be added to the trust policy as a condition

Trusted account creates an IAM user who has permission (Permission to call the AWS Security Token Service (AWS STS) AssumeRole API for the role) to assume the role/switch to the role.
IAM User in the Trusted account switches to the Role/assumes the role and passes the ARN of the role
Trusted account belonging to the Third party would also pass the External ID mapped to the Trusting account

AWS STS verifies the request for the role ARN, External ID if any and if it is from the trusted resource matching the roles’s trust policy and
AWS STS upon successful verification returns temporary credentials
Temporary credentials allow the user to access the resources of the Trusting account

When the user exits the role, the user’s permissions revert to the original permissions held before switching to the role

External ID and Confused Deputy Problem

External ID allows the user assuming the role to assert the circumstances in which they are operating.
External ID provides a way for the account owner to permit the role to be assumed only under specific circumstances and prevents an unauthorized customer from gaining access to your resources

Primary function of the external ID is to address and prevent the “confused deputy” problem.

Confused Deputy Problem

Example Corp’s AWS Account provides the services (access, analyze and process data and provide back reports) to multiple different AWS accounts.

Preferred mechanism is to have each AWS account customer define a Role that Example Corp’s AWS Account users can assume and act upon.
You provide Example Corp’s AWS Account access to your AWS account through Role and providing Role ARN.
Example Corp when working on your account assumes the IAM role and provides the ARN with the request.

As Example Corp is already trusted by your account it will receive the temporary security credentials and gain access to your resources.
If another AWS account is able to know or guess your ARN (Role with Account ID), it can provide the same to Example Corp.
Example Corp’s would use the ARN (belonging to your AWS account) to process the data but would provide the same data to the other AWS account.

This form of privilege escalation is known as the confused deputy problem

Address Confused Deputy Problem using External ID

Using External ID, Example Corp’s generates a unique External ID for each of its Customers which is known only to them and is kept secret.

Example Corp provides you with an External ID which needs to be added as a condition while defining the trust policy.
You provide Example Corp’s AWS Account access to your AWS account through Role and providing Role ARN.
Example Corp when working on your account uses the IAM role and provides the ARN along with the External ID and as it is already trusted would be able to gain access.

Other AWS accounts registered with Example Corp would have a Unique External ID assigned to them.
If the Other AWS account is able to know or guess your ARN (Role with Account ID), it can provide the same to Example Corp
Example Corp’s would request access to your Account using the ARN (belonging to your AWS account) but with the External ID belonging to Other AWS account as the request was made on its behalf.

As the External ID provided by Example Corp does not match the condition defined in the Role trust policy, the authentication would fail and hence denied access.

Identity Providers and Federation

Refer to My Blog Post about IAM Role – Identity Providers and Federation

AWS Certification Exam Practice Questions

A company is building software on AWS that requires access to various AWS services. Which configuration should be used to ensure that AWS credentials (i.e., Access Key ID/Secret Access Key combination) are not compromised?
1. Enable Multi-Factor Authentication for your AWS root account.
2. Assign an IAM role to the Amazon EC2 instance.
3. Store the AWS Access Key ID/Secret Access Key combination in software comments.
4. Assign an IAM user to the Amazon EC2 Instance.
A company is preparing to give AWS Management Console access to developers. Company policy mandates identity federation and role-based access control. Roles are currently assigned using groups in the corporate Active Directory. What combination of the following will give developers access to the AWS console? (Select 2) Choose 2 answers
1. AWS Directory Service AD Connector
2. AWS Directory Service Simple AD
3. AWS Identity and Access Management groups
4. AWS identity and Access Management roles
5. AWS identity and Access Management users
A customer needs corporate IT governance and cost oversight of all AWS resources consumed by its divisions. The divisions want to maintain administrative control of the discrete AWS resources they consume and keep those resources separate from the resources of other divisions. Which of the following options, when used together will support the autonomy/control of divisions while enabling corporate IT to maintain governance and cost oversight? Choose 2 answers
1. Use AWS Consolidated Billing and disable AWS root account access for the child accounts.
2. Enable IAM cross-account access for all corporate IT administrators in each child account. (Provides IT governance)
3. Create separate VPCs for each division within the corporate IT AWS account.
4. Use AWS Consolidated Billing to link the divisions’ accounts to a parent corporate account. (Will provide cost oversight)
5. Write all child AWS CloudTrail and Amazon CloudWatch logs to each child account’s Amazon S3 ‘Log’ bucket.
Which of the following items are required to allow an application deployed on an EC2 instance to write data to a DynamoDB table? Assume that no security keys are allowed to be stored on the EC2 instance. (Choose 2 answers)
1. Create an IAM Role that allows write access to the DynamoDB table
2. Add an IAM Role to a running EC2 instance. (With latest enhancement from AWS, IAM role can be assigned to a running EC2 instance)
3. Create an IAM User that allows write access to the DynamoDB table.
4. Add an IAM User to a running EC2 instance.
5. Launch an EC2 Instance with the IAM Role included in the launch configuration (This was the correct answer before, as AWS did not allow IAM role to be added to an existing instance)
You are looking to migrate your Development (Dev) and Test environments to AWS. You have decided to use separate AWS accounts to host each environment. You plan to link each accounts bill to a Master AWS account using Consolidated Billing. To make sure you Keep within budget you would like to implement a way for administrators in the Master account to have access to stop, delete and/or terminate resources in both the Dev and Test accounts. Identify which option will allow you to achieve this goal. [PROFESSIONAL]
1. Create IAM users in the Master account with full Admin permissions. Create cross-account roles in the Dev and Test accounts that grant the Master account access to the resources in the account by inheriting permissions from the Master account.
2. Create IAM users and a cross-account role in the Master account that grants full Admin permissions to the Dev and Test accounts.
3. Create IAM users in the Master account Create cross-account roles in the Dev and Test accounts that have full Admin permissions and grant the Master account access
4. Link the accounts using Consolidated Billing. This will give IAM users in the Master account access to resources in the Dev and Test accounts

You have an application running on an EC2 Instance which will allow users to download flies from a private S3 bucket using a pre-assigned URL. Before generating the URL the application should verify the existence of the file in S3. How should the application use AWS credentials to access the S3 bucket securely? [PROFESSIONAL]
1. Use the AWS account access Keys the application retrieves the credentials from the source code of the application.
2. Create a IAM user for the application with permissions that allow list access to the S3 bucket launch the instance as the IAM user and retrieve the IAM user’s credentials from the EC2 instance user data.
3. Create an IAM role for EC2 that allows list access to objects in the S3 bucket. Launch the instance with the role, and retrieve the role’s credentials from the EC2 Instance metadata
4. Create an IAM user for the application with permissions that allow list access to the S3 bucket. The application retrieves the IAM user credentials from a temporary directory with permissions that allow read access only to the application user.
An administrator is using Amazon CloudFormation to deploy a three tier web application that consists of a web tier and application tier that will utilize Amazon DynamoDB for storage when creating the CloudFormation template which of the following would allow the application instance access to the DynamoDB tables without exposing API credentials? [PROFESSIONAL]
1. Create an Identity and Access Management Role that has the required permissions to read and write from the required DynamoDB table and associate the Role to the application instances by referencing an instance profile.
2. Use the Parameter section in the Cloud Formation template to nave the user input Access and Secret Keys from an already created IAM user that has me permissions required to read and write from the required DynamoDB table.
3. Create an Identity and Access Management Role that has the required permissions to read and write from the required DynamoDB table and reference the Role in the instance profile property of the application instance.
4. Create an identity and Access Management user in the CloudFormation template that has permissions to read and write from the required DynamoDB table, use the GetAtt function to retrieve the Access and secret keys and pass them to the application instance through user-data.
An enterprise wants to use a third-party SaaS application. The SaaS application needs to have access to issue several API commands to discover Amazon EC2 resources running within the enterprise’s account. The enterprise has internal security policies that require any outside access to their environment must conform to the principles of least privilege and there must be controls in place to ensure that the credentials used by the SaaS vendor cannot be used by any other third party. Which of the following would meet all of these conditions? [PROFESSIONAL]
1. From the AWS Management Console, navigate to the Security Credentials page and retrieve the access and secret key for your account.
2. Create an IAM user within the enterprise account assign a user policy to the IAM user that allows only the actions required by the SaaS application create a new access and secret key for the user and provide these credentials to the SaaS provider.
3. Create an IAM role for cross-account access allows the SaaS provider’s account to assume the role and assign it a policy that allows only the actions required by the SaaS application.
4. Create an IAM role for EC2 instances, assign it a policy mat allows only the actions required tor the SaaS application to work, provide the role ARM to the SaaS provider to use when launching their application instances.

A user has created an application which will be hosted on EC2. The application makes calls to DynamoDB to fetch certain data. The application is using the DynamoDB SDK to connect with from the EC2 instance. Which of the below mentioned statements is true with respect to the best practice for security in this scenario?
1. The user should attach an IAM role with DynamoDB access to the EC2 instance
2. The user should create an IAM user with DynamoDB access and use its credentials within the application to connect with DynamoDB
3. The user should create an IAM role, which has EC2 access so that it will allow deploying the application
4. The user should create an IAM user with DynamoDB and EC2 access. Attach the user with the application so that it does not use the root account credentials
A customer is in the process of deploying multiple applications to AWS that are owned and operated by different development teams. Each development team maintains the authorization of its users independently from other teams. The customer’s information security team would like to be able to delegate user authorization to the individual development teams but independently apply restrictions to the users permissions based on factors such as the users device and location. For example, the information security team would like to grant read-only permissions to a user who is defined by the development team as read/write whenever the user is authenticating from outside the corporate network. What steps can the information security team take to implement this capability? [PROFESSIONAL]
1. Operate an authentication service that generates AWS STS tokens with IAM policies from application-defined IAM roles. (no user separation, will just help generate temporary tokens)
2. Add additional IAM policies to the application IAM roles that deny user privileges based on information security policy. (Different policy with deny rules based on location, device and more restrictive wins)
3. Configure IAM policies that restrict modification of the application IAM roles only to the information security team. (Authorization should still be in developers control)
4. Enable federation with the internal LDAP directory and grant the application teams permissions to modify users.
You are creating an Auto Scaling group whose Instances need to insert a custom metric into CloudWatch. Which method would be the best way to authenticate your CloudWatch PUT request?
1. Create an IAM role with the Put MetricData permission and modify the Auto Scaling launch configuration to launch instances in that role
2. Create an IAM user with the PutMetricData permission and modify the Auto Scaling launch configuration to inject the users credentials into the instance User Data
3. Modify the appropriate Cloud Watch metric policies to allow the Put MetricData permission to instances from the Auto Scaling group
4. Create an IAM user with the PutMetricData permission and put the credentials in a private repository and have applications on the server pull the credentials as needed

References

AWS_IAM_Role

Amazon CloudWatch

December 31, 2022 ~ Last updated on : January 9, 2023 ~ jayendrapatil ~ 51 Comments

Amazon CloudWatch

CloudWatch monitors AWS resources and applications in real time.

CloudWatch can be used to collect and track metrics, which are the variables to be measured for resources and applications.
CloudWatch is basically a metrics repository where the metrics can be inserted and statistics retrieved based on those metrics.

In addition to monitoring the built-in metrics that come with AWS, custom metrics can also be monitored
CloudWatch provides system-wide visibility into resource utilization, application performance, and operational health.
By default, CloudWatch stores the log data indefinitely, and the retention can be changed for each log group at any time.

CloudWatch alarms can be configured
- to send notifications or
- to automatically make changes to the resources based on defined rules

CloudWatch dashboards are customizable home pages in the CloudWatch console used to monitor the resources in a single view, even those resources that are spread across different Regions.
CloudWatch Agent helps collect metrics and logs from EC2 instances and on-premises servers and push them to CloudWatch.

CloudWatch Architecture

CloudWatch collects various metrics from various resources

These metrics, as statistics, are available to the user through Console, CLI
CloudWatch allows the creation of alarms with defined rules
- to perform actions to auto-scaling or stop, start, or terminate instances
- to send notifications using SNS actions on your behalf

CloudWatch Concepts

Namespaces

CloudWatch namespaces are containers for metrics.

Metrics in different namespaces are isolated from each other, so that metrics from different applications are not mistakenly aggregated into the same statistics.
AWS namespaces all follow the convention AWS/<service>, for e.g. AWS/EC2 and AWS/ELB
Namespace names must be fewer than 256 characters in length.

There is no default namespace. Each data element put into CloudWatch must specify a namespace.

Metrics

Metric is the fundamental concept in CloudWatch.
Uniquely defined by a name, a namespace, and one or more dimensions.

Represents a time-ordered set of data points published to CloudWatch.
Each data point has a time stamp, and (optionally) a unit of measure.
Data points can be either custom metrics or metrics from other
services in AWS.

Statistics can be retrieved about those data points as an ordered set of time-series data that occur within a specified time window.
When the statistics are requested, the returned data stream is identified by namespace, metric name, dimension, and (optionally) the unit.
Metrics exist only in the region in which they are created.

CloudWatch stores the metric data for two weeks
Metrics cannot be deleted, but they automatically expire after 15 months, if no new data is published to them.
Metric retention is as follows
- Data points with a period of less than 60 seconds are available for 3 hours. These data points are high-resolution custom metrics.
- Data points with a 60 secs (1 min) period are available for 15 days
- Data points with a 300 secs (5 min) period are available for 63 days
- Data points with a 3600 secs (1 hour) period are available for 455 days (15 months)

Dimensions

A dimension is a name/value pair that uniquely identifies a metric.
Every metric has specific characteristics that describe it, and you can think of dimensions as categories for those characteristics.

Dimensions help design a structure for the statistics plan.
Dimensions are part of the unique identifier for a metric, whenever a unique name pair is added to one of the metrics, a new metric is created.
Dimensions can be used to filter result sets that CloudWatch query returns.

A metric can be assigned up to ten dimensions to a metric.

Time Stamps

Each metric data point must be marked with a time stamp to identify the data point on a time series.
Timestamp can be up to two weeks in the past and up to two hours into the future.

If no timestamp is provided, a time stamp based on the time the data element was received is created.
All times reflect the UTC time zone when statistics are retrieved

Resolution

Each metric is one of the following:
- Standard resolution, with data having a one-minute granularity
- High resolution, with data at a granularity of one second

Units

Units represent the statistic’s unit of measure e.g. count, bytes, %, etc

Statistics

Statistics are metric data aggregations over specified periods of time
Aggregations are made using the namespace, metric name, dimensions, and the data point unit of measure, within the specified time period

Periods

Period is the length of time associated with a specific statistic.

Each statistic represents an aggregation of the metrics data collected for a specified period of time.
Although periods are expressed in seconds, the minimum granularity for a period is one minute.

Aggregation

CloudWatch aggregates statistics according to the period length specified in calls to GetMetricStatistics.

Multiple data points can be published with the same or similar time stamps. CloudWatch aggregates them by period length when the statistics about those data points are requested.
Aggregated statistics are only available when using detailed monitoring.
Instances that use basic monitoring are not included in the aggregates

CloudWatch does not aggregate data across regions.

Alarms

Alarms can automatically initiate actions on behalf of the user, based on specified parameters.
Alarm watches a single metric over a specified time period, and performs one or more actions based on the value of the metric relative to a given threshold over a number of time periods.

Alarms invoke actions for sustained state changes only i.e. the state must have changed and been maintained for a specified number of periods.
Action can be a
- SNS notification
- Auto Scaling policies
- EC2 action – stop or terminate EC2 instances
After an alarm invokes an action due to a change in state, its subsequent behavior depends on the type of action associated with the alarm.
- For Auto Scaling policy notifications, the alarm continues to invoke the action for every period that the alarm remains in the new state.
- For SNS notifications, no additional actions are invoked.
An alarm has three possible states:
- OK—The metric is within the defined threshold
- ALARM—The metric is outside of the defined threshold
- INSUFFICIENT_DATA—Alarm has just started, the metric is not available, or not enough data is available for the metric to determine the alarm state

Alarms exist only in the region in which they are created.
Alarm actions must reside in the same region as the alarm
Alarm history is available for the last 14 days.

Alarm can be tested by setting it to any state using the SetAlarmState API (mon-set-alarm-state command). This temporary state change lasts only until the next alarm comparison occurs.
Alarms can be disabled and enabled using the DisableAlarmActions and EnableAlarmActions APIs (mon-disable-alarm-actions and mon-enable-alarm-actions commands).

Regions

CloudWatch does not aggregate data across regions. Therefore, metrics are completely separate between regions.

Custom Metrics

CloudWatch allows publishing custom metrics with put-metric-data CLI command (or its Query API equivalent PutMetricData)
CloudWatch creates a new metric if put-metric-data is called with a new metric name, else it associates the data with the specified existing metric
put-metric-data command can only publish one data point per call

CloudWatch stores data about a metric as a series of data points and each data point has an associated time stamp
Creating a new metric using the put-metric-data command, can take up to two minutes before statistics can be retrieved on the new metric using the get-metric-statistics command and can take up to fifteen minutes before the new metric appears in the list of metrics retrieved using the list-metrics command.
CloudWatch allows publishing
- Single data point
  - Data points can be published with time stamps as granular as one-thousandth of a second, CloudWatch aggregates the data to a minimum granularity of one minute
  - CloudWatch records the average (sum of all items divided by number of items) of the values received for every 1-minute period, as well as number of samples, maximum value, and minimum value for the same time period
  - CloudWatch uses one-minute boundaries when aggregating data points
- Aggregated set of data points called a statistics set
  - Data can also be aggregated before being published to CloudWatch
  - Aggregating data minimizes the number of calls reducing it to a single call per minute with the statistic set of data
  - Statistics include Sum, Average, Minimum, Maximum, SampleCount
If the application produces data that is more sporadic and have periods that have no associated data, either a the value zero (0) or no value at all can be published

However, it can be helpful to publish zero instead of no value
- to monitor the health of your application for e.g. alarm can be configured to notify if no metrics published every 5 minutes
- to track the total number of data points
- to have statistics such as minimum and average to include data points with the value 0.

CloudWatch Dashboards

CloudWatch dashboards are customizable home pages in the CloudWatch console used to monitor the resources in a single view, even those resources that are spread across different Regions.
Dashboards can be used to create customized views of the metrics and alarms for the AWS resources.

Dashboards can help to create
- A single view for selected metrics and alarms to help assess the health of the resources and applications across one or more Regions.
- An operational playbook that provides guidance for team members during operational events about how to respond to specific incidents.
- A common view of critical resource and application measurements that can be shared by team members for faster communication flow during operational events.
CloudWatch cross-account observability helps monitor and troubleshoot applications that span multiple accounts within a Region.
Cross-account observability includes monitoring and source accounts
- A monitoring account is a central AWS account that can view and interact with observability data generated from source accounts.
- A source account is an individual AWS account that generates observability data for the resources that reside in it.
- Source accounts share their observability data with the monitoring account which can include the following types of telemetry:
  - Metrics in CloudWatch
  - Log groups in CloudWatch Logs
  - Traces in AWS X-Ray

CloudWatch Agent

CloudWatch Agent helps collect metrics and logs from EC2 instances and on-premises servers and push them to CloudWatch.
Logs collected by the unified agent are processed and stored in CloudWatch Logs.

CloudWatch Logs

Refer blog post @ CloudWatch Logs

CloudWatch Supported Services

Refer blog post @ CloudWatch Supported Services

Accessing CloudWatch

CloudWatch can be accessed using
- AWS CloudWatch console
- CloudWatch CLI
- AWS CLI
- CloudWatch API
- AWS SDKs

AWS Certification Exam Practice Questions

Questions are collected from Internet and the answers are marked as per my knowledge and understanding (which might differ with yours).

AWS services are updated everyday and both the answers and questions might be outdated soon, so research accordingly.
AWS exam questions are not updated to keep up the pace with AWS updates, so even if the underlying feature has changed the question might not be updated
Open to further feedback, discussion and correction.

A company needs to monitor the read and write IOPs metrics for their AWS MySQL RDS instance and send real-time alerts to their operations team. Which AWS services can accomplish this? Choose 2 answers
1. Amazon Simple Email Service (Cannot be integrated with CloudWatch directly)
2. Amazon CloudWatch
3. Amazon Simple Queue Service
4. Amazon Route 53
5. Amazon Simple Notification Service

A customer needs to capture all client connection information from their load balancer every five minutes. The company wants to use this data for analyzing traffic patterns and troubleshooting their applications. Which of the following options meets the customer requirements?
1. Enable AWS CloudTrail for the load balancer.
2. Enable access logs on the load balancer. (Refer link)
3. Install the Amazon CloudWatch Logs agent on the load balancer.
4. Enable Amazon CloudWatch metrics on the load balancer (does not provide Client connection information)
A user is running a batch process on EBS backed EC2 instances. The batch process starts a few instances to process Hadoop Map reduce jobs, which can run between 50 – 600 minutes or sometimes for more time. The user wants to configure that the instance gets terminated only when the process is completed. How can the user configure this with CloudWatch?
1. Setup the CloudWatch action to terminate the instance when the CPU utilization is less than 5%
2. Setup the CloudWatch with Auto Scaling to terminate all the instances
3. Setup a job which terminates all instances after 600 minutes
4. It is not possible to terminate instances automatically
A user has two EC2 instances running in two separate regions. The user is running an internal memory management tool, which captures the data and sends it to CloudWatch in US East, using a CLI with the same namespace and metric. Which of the below mentioned options is true with respect to the above statement?
1. The setup will not work as CloudWatch cannot receive data across regions
2. CloudWatch will receive and aggregate the data based on the namespace and metric
3. CloudWatch will give an error since the data will conflict due to two sources
4. CloudWatch will take the data of the server, which sends the data first

A user is sending the data to CloudWatch using the CloudWatch API. The user is sending data 90 minutes in the future. What will CloudWatch do in this case?
1. CloudWatch will accept the data
2. It is not possible to send data of the future
3. It is not possible to send the data manually to CloudWatch
4. The user cannot send data for more than 60 minutes in the future
A user is having data generated randomly based on a certain event. The user wants to upload that data to CloudWatch. It may happen that event may not have data generated for some period due to randomness. Which of the below mentioned options is a recommended option for this case?
1. For the period when there is no data, the user should not send the data at all
2. For the period when there is no data the user should send a blank value
3. For the period when there is no data the user should send the value as 0 (Refer User Guide)
4. The user must upload the data to CloudWatch as having no data for some period will cause an error at CloudWatch monitoring
A user has a weighing plant. The user measures the weight of some goods every 5 minutes and sends data to AWS CloudWatch for monitoring and tracking. Which of the below mentioned parameters is mandatory for the user to include in the request list?
1. Value
2. Namespace (refer put-metric request)
3. Metric Name
4. Timezone
A user has a refrigerator plant. The user is measuring the temperature of the plant every 15 minutes. If the user wants to send the data to CloudWatch to view the data visually, which of the below mentioned statements is true with respect to the information given above?
1. The user needs to use AWS CLI or API to upload the data
2. The user can use the AWS Import Export facility to import data to CloudWatch
3. The user will upload data from the AWS console
4. The user cannot upload data to CloudWatch since it is not an AWS service metric
A user has launched an EC2 instance. The user is planning to setup the CloudWatch alarm. Which of the below mentioned actions is not supported by the CloudWatch alarm?
1. Notify the Auto Scaling launch config to scale up
2. Send an SMS using SNS
3. Notify the Auto Scaling group to scale down
4. Stop the EC2 instance
A user has a refrigerator plant. The user is measuring the temperature of the plant every 15 minutes. If the user wants to send the data to CloudWatch to view the data visually, which of the below mentioned statements is true with respect to the information given above?
1. The user needs to use AWS CLI or API to upload the data
2. The user can use the AWS Import Export facility to import data to CloudWatch
3. The user will upload data from the AWS console
4. The user cannot upload data to CloudWatch since it is not an AWS service metric
A user is trying to aggregate all the CloudWatch metric data of the last 1 week. Which of the below mentioned statistics is not available for the user as a part of data aggregation?
1. Aggregate
2. Sum
3. Sample data
4. Average
A user has setup a CloudWatch alarm on an EC2 action when the CPU utilization is above 75%. The alarm sends a notification to SNS on the alarm state. If the user wants to simulate the alarm action how can he achieve this?
1. Run activities on the CPU such that its utilization reaches above 75%
2. From the AWS console change the state to ‘Alarm’
3. The user can set the alarm state to ‘Alarm’ using CLI
4. Run the SNS action manually
A user is publishing custom metrics to CloudWatch. Which of the below mentioned statements will help the user understand the functionality better?
1. The user can use the CloudWatch Import tool
2. The user should be able to see the data in the console after around 15 minutes
3. If the user is uploading the custom data, the user must supply the namespace, timezone, and metric name as part of the command
4. The user can view as well as upload data using the console, CLI and APIs
An application that you are managing has EC2 instances and DynamoDB tables deployed to several AWS Regions. In order to monitor the performance of the application globally, you would like to see two graphs 1) Avg CPU Utilization across all EC2 instances and 2) Number of Throttled Requests for all DynamoDB tables. How can you accomplish this? [PROFESSIONAL]
1. Tag your resources with the application name, and select the tag name as the dimension in the CloudWatch Management console to view the respective graphs (CloudWatch metrics are regional)
2. Use the CloudWatch CLI tools to pull the respective metrics from each regional endpoint. Aggregate the data offline & store it for graphing in CloudWatch.
3. Add SNMP traps to each instance and DynamoDB table. Leverage a central monitoring server to capture data from each instance and table. Put the aggregate data into CloudWatch for graphing (Can’t add SNMP traps to DynamoDB as it is a managed service)
4. Add a CloudWatch agent to each instance and attach one to each DynamoDB table. When configuring the agent set the appropriate application name & view the graphs in CloudWatch. (Can’t add agents to DynamoDB as it is a managed service)
You have set up Individual AWS accounts for each project. You have been asked to make sure your AWS Infrastructure costs do not exceed the budget set per project for each month. Which of the following approaches can help ensure that you do not exceed the budget each month? [PROFESSIONAL]
1. Consolidate your accounts so you have a single bill for all accounts and projects (Consolidation will not help limit per account)
2. Set up auto scaling with CloudWatch alarms using SNS to notify you when you are running too many Instances in a given account (many instances do not directly map to cost and would not give exact cost)
3. Set up CloudWatch billing alerts for all AWS resources used by each project, with a notification occurring when the amount for each resource tagged to a particular project matches the budget allocated to the project. (as each project already has a account, no need for resource tagging)
4. Set up CloudWatch billing alerts for all AWS resources used by each account, with email notifications when it hits 50%. 80% and 90% of its budgeted monthly spend
You meet once per month with your operations team to review the past month’s data. During the meeting, you realize that 3 weeks ago, your monitoring system which pings over HTTP from outside AWS recorded a large spike in latency on your 3-tier web service API. You use DynamoDB for the database layer, ELB, EBS, and EC2 for the business logic tier, and SQS, ELB, and EC2 for the presentation layer. Which of the following techniques will NOT help you figure out what happened?
1. Check your CloudTrail log history around the spike’s time for any API calls that caused slowness.
2. Review CloudWatch Metrics graphs to determine which component(s) slowed the system down. (Metrics data was available for 2 weeks before, however it has been extended now)
3. Review your ELB access logs in S3 to see if any ELBs in your system saw the latency.
4. Analyze your logs to detect bursts in traffic at that time.
You have a high security requirement for your AWS accounts. What is the most rapid and sophisticated setup you can use to react to AWS API calls to your account?
1. Subscription to AWS Config via an SNS Topic. Use a Lambda Function to perform in-flight analysis and reactivity to changes as they occur.
2. Global AWS CloudTrail setup delivering to S3 with an SNS subscription to the deliver notifications, pushing into a Lambda, which inserts records into an ELK stack for analysis.
3. Use a CloudWatch Rule ScheduleExpression to periodically analyze IAM credential logs. Push the deltas for events into an ELK stack and perform ad-hoc analysis there.
4. CloudWatch Events Rules, which trigger based on all AWS API calls, submitting all events to an AWS Kinesis Stream for arbitrary downstream analysis. (CloudWatch Events allow subscription to AWS API calls, and direction of these events into Kinesis Streams. This allows a unified, near real-time stream for all API calls, which can be analyzed with any tool(s). Refer link)
To monitor API calls against our AWS account by different users and entities, we can use ____ to create a history of calls in bulk for later review, and use ____ for reacting to AWS API calls in real-time.
1. AWS Config; AWS Inspector
2. AWS CloudTrail; AWS Config
3. AWS CloudTrail; CloudWatch Events (CloudTrail is a batch API call collection service, CloudWatch Events enables real-time monitoring of calls through the Rules object interface. Refer link)
4. AWS Config; AWS Lambda
You are hired as the new head of operations for a SaaS company. Your CTO has asked you to make debugging any part of your entire operation simpler and as fast as possible. She complains that she has no idea what is going on in the complex, service-oriented architecture, because the developers just log to disk, and it’s very hard to find errors in logs on so many services. How can you best meet this requirement and satisfy your CTO? [PROFESSIONAL]
1. Copy all log files into AWS S3 using a cron job on each instance. Use an S3 Notification Configuration on the <code>PutBucket</code> event and publish events to AWS Lambda. Use the Lambda to analyze logs as soon as they come in and flag issues. (is not fast in search and introduces delay)
2. Begin using CloudWatch Logs on every service. Stream all Log Groups into S3 objects. Use AWS EMR cluster jobs to perform adhoc MapReduce analysis and write new queries when needed. (is not fast in search and introduces delay)
3. Copy all log files into AWS S3 using a cron job on each instance. Use an S3 Notification Configuration on the <code>PutBucket</code> event and publish events to AWS Kinesis. Use Apache Spark on AWS EMR to perform at-scale stream processing queries on the log chunks and flag issues. (is not fast in search and introduces delay)
4. Begin using CloudWatch Logs on every service. Stream all Log Groups into an AWS Elasticsearch Service Domain running Kibana 4 and perform log analysis on a search cluster. (ELK – Elasticsearch, Kibana stack is designed specifically for real-time, ad-hoc log analysis and aggregation)
Your EC2-Based Multi-tier application includes a monitoring instance that periodically makes application -level read only requests of various application components and if any of those fail more than three times 30 seconds calls CloudWatch to fire an alarm, and the alarm notifies your operations team by email and SMS of a possible application health problem. However, you also need to watch the watcher -the monitoring instance itself – and be notified if it becomes unhealthy. Which of the following is a simple way to achieve that goal? [PROFESSIONAL]
1. Run another monitoring instance that pings the monitoring instance and fires a could watch alarm mat notifies your operations team should the primary monitoring instance become unhealthy.
2. Set a CloudWatch alarm based on EC2 system and instance status checks and have the alarm notify your operations team of any detected problem with the monitoring instance.
3. Set a CloudWatch alarm based on the CPU utilization of the monitoring instance and nave the alarm notify your operations team if C r the CPU usage exceeds 50% few more than one minute: then have your monitoring application go into a CPU-bound loop should it Detect any application problems.
4. Have the monitoring instances post messages to an SOS queue and then dequeue those messages on another instance should the queue cease to have new messages, the second instance should first terminate the original monitoring instance start another backup monitoring instance and assume (the role of the previous monitoring instance and beginning adding messages to the SQS queue.

AWS IAM – Identity Access Management

December 31, 2022 ~ Last updated on : January 2, 2023 ~ jayendrapatil ~ 36 Comments

AWS IAM – Identity Access Management

AWS IAM – Identity and Access Management is a web service that helps you securely control access to AWS resources for your users.

IAM is used to control
- Identity – who can use your AWS resources (authentication)
- Access – what resources they can use and in what ways (authorization)
IAM can also keep the account credentials private.
With IAM, multiple users can be created under the umbrella of the AWS account or temporary access can be enabled through identity federation with the corporate directory or third-party providers.

IAM also enables access to resources across AWS accounts.

IAM Features

Shared access to your AWS account
- Grant other people permission to administer and use resources in your AWS account without having to share your password or access key.

Granular permissions
- Each user can be granted a different set of granular permissions as required to perform their job
Secure access to AWS resources for applications that run on EC2
- can help provide applications running on EC2 instance temporary credentials that they need in order to access other AWS resources
Identity federation
- allows users to access AWS resources, without requiring the user to have accounts with AWS, by providing temporary credentials for e.g. through corporate network or Google or Amazon authentication

Identity information for assurance
- CloudTrail can be used to receive log records that include information about those who made requests for resources in the account.
PCI DSS Compliance
- supports the processing, storage, and transmission of credit card data by a merchant or service provider, and has been validated as being Payment Card Industry Data Security Standard (PCI DSS) compliant
Integrated with many AWS services
- integrates with almost all the AWS services

Eventually Consistent
- is eventually consistent and achieves high availability by replicating data across multiple servers within Amazon’s data centers around the world.
- Changes made to IAM would be eventually consistent and hence would take some time to reflect

Free to use
- is offered at no additional charge and charges are applied only for use of other AWS products by your IAM users.
AWS Security Token Service
- provides STS which is an included feature of the AWS account offered at no additional charge.
- AWS charges only for the use of other AWS services accessed by the AWS STS temporary security credentials.

Identities

IAM identities determine who can access and help to provide authentication for people and processes in your AWS account

IAM Identities

Account Root User

Root Account Credentials are the email address and password with which you sign in to the AWS account.
Root Credentials has full unrestricted access to AWS account including the account security credentials which include sensitive information

IAM Best Practice – Do not use or share the Root account once the AWS account is created, instead create a separate user with admin privilege
An Administrator account can be created for all the activities which also have full access to the AWS account except for the accounts security credentials, billing information, and ability to change the password.

IAM Users

IAM user represents the person or service who uses the access to interact with AWS.

IAM Best Practice – Create Individual Users, do not share credentials.
User credentials can consist of the following
- Password to access AWS services through AWS Management Console
- Access Key/Secret Access Key to access AWS services through API, CLI, or SDK
A user starts with no permissions and is not authorized to perform any AWS actions on any AWS resources and should be granted permissions as per the job function requirement
IAM Best Practice – Grant Least Privilege

Each user is associated with one and only one AWS account.
A user cannot be renamed from the AWS management console and has to be done from CLI or SDK tools.
IAM handles the renaming of user w.r.t unique id, groups, and policies where the user was mentioned as a principal. However, you need to handle the renaming in the policies where the user was mentioned as a resource

IAM Groups

IAM group is a collection of IAM users
Groups can be used to specify permissions for a collection of users sharing the same job function making it easier to manage
IAM Best Practice – Use groups to assign permissions to IAM Users

A group is not truly an identity because it cannot be identified as a Principal in an access policy. It is only a way to attach policies to multiple users at one time
A group can have multiple users, while a user can belong to multiple groups (10 max)
Groups cannot be nested and can only have users within it

AWS does not provide any default group to hold all users in it and if one is required it should be created with all users assigned to it.
IAM handles the renaming of a group name or path w.r.t to policies attached to the group, unique ids, and users within the group. However, IAM does not update the policies where the group is mentioned as a resource and must be handled manually
Deletion of the groups requires you to detach users and managed policies and delete any inline policies before deleting the group. With the AWS management console, the deletion and detachment are taken care of.

IAM Roles

IAM role is very similar to a user, in that it is an identity with permission policies that determine what the identity can and cannot do in AWS.
IAM role is not intended to be uniquely associated with a particular user, group, or service and is intended to be assumable by anyone who needs it.
Role does not have any static credentials (password or access keys) associated with it and whoever assumes the role is provided with dynamic temporary credentials.

Role helps in access delegation to grant permissions to someone that allows access to resources that you control.
Roles can help to prevent accidental access to or modification of sensitive resources.
Modification of a Role can be done anytime and the changes are reflected across all the entities associated with the Role immediately.

IAM Role plays a very important role in the following scenarios
- Services like EC2 instances running an application that needs to access other AWS services.
- Cross-Account access – Allowing users from different AWS accounts to have access to AWS resources in a different account, instead of having to create users.
- Identity Providers & Federation
  - Company uses a Corporate Authentication mechanism and doesn’t want the User to authenticate twice or create duplicate users in AWS
  - Applications allowing login through external authentication mechanisms e.g. Amazon, Facebook, Google, etc

Role can be assumed by
- IAM user within the same AWS account
- IAM user from a different AWS account
- AWS services such as EC2, EMR to interact with other services
- An external user authenticated by an external identity provider (IdP) service that is compatible with SAML 2.0 or OpenID Connect (OIDC), or a custom-built identity broker.
Role involves defining two policies
- Trust policy
  - Trust policy defines – who can assume the role
  - Trust policy involves setting up a trust between the account that owns the resource (trusting account) and the account that owns the user that needs access to the resources (trusted account).
- Permissions policy
  - Permissions policy defines – what they can access
  - Permissions policy determines authorization, which grants the user of the role with the needed permissions to carry out the desired tasks on the resource

Federation is creating a trust relationship between an external Identity Provider (IdP) and AWS.
- Users can also sign in to an enterprise identity system that is compatible with SAML
- Users can sign in to a web identity provider, such as Login with Amazon, Facebook, Google, or any IdP that is compatible with OpenID connect (OIDC).
- When using OIDC and SAML 2.0 to configure a trust relationship between these external identity providers and AWS, the user is assigned to an IAM role and receives temporary credentials that enable the user to access AWS resources.
IAM Best Practice – Use roles for applications running on EC2 instances
IAM Best Practice – Delegate using roles instead of sharing credentials

Multi-Factor Authentication – MFA

For increased security and to help protect the AWS resources, Multi-Factor authentication can be configured
IAM Best Practice – Enable MFA on Root accounts and privilege users
Multi-Factor Authentication can be configured using
- Security token-based
  - AWS Root user or IAM user can be assigned a hardware/virtual MFA device
  - Device generates a six-digit numeric code based upon a time-synchronized one-time password algorithm which needs to be provided during authentication
- SMS text message-based (Preview Mode)
  - IAM user can be configured with the phone number of the user’s SMS-compatible mobile device which would receive a 6 digit code from AWS
  - SMS-based MFA is available only for IAM users and does not work for AWS root account

MFA needs to be enabled on the Root user and IAM user separately as they are distinct entities.
Enabling MFA on Root does not enable it for all other users
MFA devices can be associated with only one AWS account or IAM user and vice versa.

If the MFA device stops working or is lost, you won’t be able to login into the AWS console and would need to reach out to AWS support to deactivate MFA.
MFA protection can be enabled for service API’s calls using "Condition": {"Bool": {"aws:MultiFactorAuthPresent": "true"}} and is available only if the service supports temporary security credentials.

IAM Access Management

Refer Blog Post @ IAM Policy and Permissions

IAM Credential Report

IAM allows you to generate and download a credential report that lists all users in the account and the status of their various credentials, including passwords, access keys, and MFA devices.
Credential report can be used to assist in auditing and compliance efforts
Credential report can be used to audit the effects of credential lifecycle requirements, such as password and access key rotation.

IAM Best Practice – Perform Audits and Remove all unused users and credentials
Credential report is generated as often as once every four hours. If the existing report was generated in less than four hours, the same is available for download. If more than four hours, IAM generates and downloads a new report.

IAM Access Analyzer

IAM Access Analyzer helps
- identify resources in the organization and accounts that are shared with an external entity.
- validate IAM policies against policy grammar and best practices.
- generate IAM policies based on access activity in your CloudTrail logs.

AWS Certification Exam Practice Questions

Which service enables AWS customers to manage users and permissions in AWS?
1. AWS Access Control Service (ACS)
2. AWS Identity and Access Management (IAM)
3. AWS Identity Manager (AIM)
IAM provides several policy templates you can use to automatically assign permissions to the groups you create. The _____ policy template gives the Admins group permission to access all account resources, except your AWS account information
1. Read Only Access
2. Power User Access
3. AWS Cloud Formation Read Only Access
4. Administrator Access
Every user you create in the IAM system starts with _________.
1. Partial permissions
2. Full permissions
3. No permissions
Groups can’t _____.
1. be nested more than 3 levels
2. be nested at all
3. be nested more than 4 levels
4. be nested more than 2 levels
The _____ service is targeted at organizations with multiple users or systems that use AWS products such as Amazon EC2, Amazon SimpleDB, and the AWS Management Console.
1. Amazon RDS
2. AWS Integrity Management
3. AWS Identity and Access Management
4. Amazon EMR

An AWS customer is deploying an application that is composed of an AutoScaling group of EC2 Instances. The customers security policy requires that every outbound connection from these instances to any other service within the customers Virtual Private Cloud must be authenticated using a unique x.509 certificate that contains the specific instanceid. In addition an x.509 certificates must be designed by the customer’s Key management service in order to be trusted for authentication. Which of the following configurations will support these requirements?
1. Configure an IAM Role that grants access to an Amazon S3 object containing a signed certificate and configure the Auto Scaling group to launch instances with this role. Have the instances bootstrap get the certificate from Amazon S3 upon first boot.
2. Embed a certificate into the Amazon Machine Image that is used by the Auto Scaling group. Have the launched instances generate a certificate signature request with the instance’s assigned instance-id to the Key management service for signature.
3. Configure the Auto Scaling group to send an SNS notification of the launch of a new instance to the trusted key management service. Have the Key management service generate a signed certificate and send it directly to the newly launched instance.
4. Configure the launched instances to generate a new certificate upon first boot. Have the Key management service poll the AutoScaling group for associated instances and send new instances a certificate signature that contains the specific instance-id.
When assessing an organization AWS use of AWS API access credentials which of the following three credentials should be evaluated? Choose 3 answers
1. Key pairs
2. Console passwords
3. Access keys
4. Signing certificates
5. Security Group memberships (required for EC2 instance access)
An organization has created 50 IAM users. The organization wants that each user can change their password but cannot change their access keys. How can the organization achieve this?
1. The organization has to create a special password policy and attach it to each user
2. The root account owner has to use CLI which forces each IAM user to change their password on first login
3. By default each IAM user can modify their passwords
4. Root account owner can set the policy from the IAM console under the password policy screen
An organization has created 50 IAM users. The organization has introduced a new policy which will change the access of an IAM user. How can the organization implement this effectively so that there is no need to apply the policy at the individual user level?
1. Use the IAM groups and add users as per their role to different groups and apply policy to group
2. The user can create a policy and apply it to multiple users in a single go with the AWS CLI
3. Add each user to the IAM role as per their organization role to achieve effective policy setup
4. Use the IAM role and implement access at the role level

Your organization’s security policy requires that all privileged users either use frequently rotated passwords or one-time access credentials in addition to username/password. Which two of the following options would allow an organization to enforce this policy for AWS users? Choose 2 answers
1. Configure multi-factor authentication for privileged IAM users
2. Create IAM users for privileged accounts (can set password policy)
3. Implement identity federation between your organization’s Identity provider leveraging the IAM Security Token Service
4. Enable the IAM single-use password policy option for privileged users (no such option the password expiration can be set from 1 to 1095 days)
Your organization is preparing for a security assessment of your use of AWS. In preparation for this assessment, which two IAM best practices should you consider implementing? Choose 2 answers
1. Create individual IAM users for everyone in your organization
2. Configure MFA on the root account and for privileged IAM users
3. Assign IAM users and groups configured with policies granting least privilege access
4. Ensure all users have been assigned and are frequently rotating a password, access ID/secret key, and X.509 certificate
A company needs to deploy services to an AWS region which they have not previously used. The company currently has an AWS identity and Access Management (IAM) role for the Amazon EC2 instances, which permits the instance to have access to Amazon DynamoDB. The company wants their EC2 instances in the new region to have the same privileges. How should the company achieve this?
1. Create a new IAM role and associated policies within the new region
2. Assign the existing IAM role to the Amazon EC2 instances in the new region
3. Copy the IAM role and associated policies to the new region and attach it to the instances
4. Create an Amazon Machine Image (AMI) of the instance and copy it to the desired region using the AMI Copy feature
After creating a new IAM user which of the following must be done before they can successfully make API calls?
1. Add a password to the user.
2. Enable Multi-Factor Authentication for the user.
3. Assign a Password Policy to the user.
4. Create a set of Access Keys for the user
An organization is planning to create a user with IAM. They are trying to understand the limitations of IAM so that they can plan accordingly. Which of the below mentioned statements is not true with respect to the limitations of IAM?
1. One IAM user can be a part of a maximum of 5 groups (Refer link)
2. Organization can create 100 groups per AWS account
3. One AWS account can have a maximum of 5000 IAM users
4. One AWS account can have 250 roles
Within the IAM service a GROUP is regarded as a:
1. A collection of AWS accounts
2. It’s the group of EC2 machines that gain the permissions specified in the GROUP.
3. There’s no GROUP in IAM, but only USERS and RESOURCES.
4. A collection of users.
Is there a limit to the number of groups you can have?
1. Yes for all users except root
2. No
3. Yes unless special permission granted
4. Yes for all users
What is the default maximum number of MFA devices in use per AWS account (at the root account level)?
1. 1
2. 5
3. 15
4. 10
When you use the AWS Management Console to delete an IAM user, IAM also deletes any signing certificates and any access keys belonging to the user.
1. FALSE
2. This is configurable
3. TRUE
You are setting up a blog on AWS. In which of the following scenarios will you need AWS credentials? (Choose 3)
1. Sign in to the AWS management console to launch an Amazon EC2 instance
2. Sign in to the running instance to instance some software (needs ssh keys)
3. Launch an Amazon RDS instance
4. Log into your blog’s content management system to write a blog post (need to authenticate using blog authentication)
5. Post pictures to your blog on Amazon S3
An organization has 500 employees. The organization wants to set up AWS access for each department. Which of the below mentioned options is a possible solution?
1. Create IAM roles based on the permission and assign users to each role
2. Create IAM users and provide individual permission to each
3. Create IAM groups based on the permission and assign IAM users to the groups
4. It is not possible to manage more than 100 IAM users with AWS
An organization has hosted an application on the EC2 instances. There will be multiple users connecting to the instance for setup and configuration of application. The organization is planning to implement certain security best practices. Which of the below mentioned pointers will not help the organization achieve better security arrangement?
1. Apply the latest patch of OS and always keep it updated.
2. Allow only IAM users to connect with the EC2 instances with their own secret access key. (Refer link)
3. Disable the password-based login for all the users. All the users should use their own keys to connect with the instance securely.
4. Create a procedure to revoke the access rights of the individual user when they are not required to connect to EC2 instance anymore for the purpose of application configuration.

AWS Application Discovery Service

December 30, 2022 ~ jayendrapatil

AWS Application Discovery Service

AWS Application Discovery Service helps plan migration to the AWS cloud by collecting usage and configuration data about the on-premises servers.

helps enterprises obtain a snapshot of the current state of their data center servers by collecting server specification information, hardware configuration, performance data, details of running processes, and network connections
is integrated with AWS Migration Hub,
- which simplifies migration tracking as it aggregates migration status information into a single console.
- can help view the discovered servers, group them into applications, and then track the migration status of each application.
discovered data for all the regions is stored in the AWS Migration Hub home Region.

The data can be exported for analysis in Microsoft Excel or AWS analysis tools such as Amazon Athena and Amazon QuickSight.
supports both agent and agentless-based on-premises tooling, in addition to file-based import for performing discovery and collecting data about the on-premises servers.

Application Discovery Service Modes

Agentless discovery

is an on-premises application that collects information through agentless methods.

can be performed by deploying the Agentless Collector (OVA file) through the VMware vCenter.
After Agentless Collector is configured,
- it identifies VMs and hosts associated with vCenter.
- collects the following static configuration data: Server hostnames, IP addresses, MAC addresses, and disk resource allocations.
- Additionally, it collects the utilization data for each VM and computes average and peak utilization for metrics such as CPU, RAM, and Disk I/O.

Agent-based discovery

can be performed by deploying the Application Discovery Agent on each of the VMs and physical servers.

supports most Windows and Linux operating systems.
can be deployed on physical on-premises servers, EC2 instances, and virtual machines.
collects static configuration data, detailed time-series system-performance information, inbound and outbound network connections, and processes that are running.

pings the Discovery Service at 15-minute intervals for configuration information.
transmits data securely to the Discovery Service using TLS encryption.

AWS Certification Exam Practice Questions

A company is migrating its on-premises systems to AWS. The user environment consists of the following systems:
• Windows and Linux virtual machines running on VMware.
• Physical servers running Red Hat Enterprise Linux.
The company wants to be able to perform the following steps before migrating to AWS:
• Identify dependencies between on-premises systems.
• Group systems together into applications to build migration plans.
How can these requirements be met?
1. Install the AWS Systems Manager Discovery Agent on each of the on-premises systems.
2. Install the AWS Application Discovery Service Discovery Agent on each of the on-premises systems.
3. Install the AWS Application Discovery Service Discovery Connector on each of the on-premises systems and in VMware vCenter.
4. Install the AWS Application Discovery Service Discovery Agent on the physical on-premises servers. Install the AWS Application Discovery Service Discovery Connector in VMware vCenter.

References

AWS_Application_Discovery_Service

AWS Simple Notification Service – SNS

December 30, 2022 ~ Last updated on : December 30, 2022 ~ jayendrapatil ~ 8 Comments

Simple Notification Service – SNS

Simple Notification Service – SNS is a web service that coordinates and manages the delivery or sending of messages to subscribing endpoints or clients.

SNS provides the ability to create a Topic which is a logical access point and communication channel.
Each topic has a unique name that identifies the SNS endpoint for publishers to post messages and subscribers to register for notifications.

Producers and Consumers communicate asynchronously with subscribers by producing and sending a message on a topic.
Producers push messages to the topic, they created or have access to, and SNS matches the topic to a list of subscribers who have subscribed to that topic and delivers the message to each of those subscribers.
Subscribers receive all messages published to the topics to which they subscribe, and all subscribers to a topic receive the same messages.

Subscribers (i.e., web servers, email addresses, SQS queues, AWS Lambda functions) consume or receive the message or notification over one of the supported protocols (i.e., SQS, HTTP/S, email, SMS, Lambda) when they are subscribed to the topic.

Accessing SNS

Amazon Management console
- Amazon Management console is the web-based user interface that can be used to manage SNS
AWS Command-line Interface (CLI)
- Provides commands for a broad set of AWS products, and is supported on Windows, Mac, and Linux.

AWS Tools for Windows Powershell
- Provides commands for a broad set of AWS products for those who script in the PowerShell environment
AWS SNS Query API
- Query API allows for requests are HTTP or HTTPS requests that use the HTTP verbs GET or POST and a Query parameter named Action
AWS SDK libraries
- AWS provides libraries in various languages which provide basic functions that automate tasks such as cryptographically signing your requests, retrying requests, and handling error responses

SNS Supported Transport Protocols

HTTP, HTTPS – Subscribers specify a URL as part of the subscription registration; notifications will be delivered through an HTTP POST to the specified URL.
Email, Email-JSON – Messages are sent to registered addresses as email. Email-JSON sends notifications as a JSON object, while Email sends text-based email.
SQS – Users can specify an SQS queue as the endpoint; SNS will enqueue a notification message to the specified queue (which subscribers can then process using SQS APIs such as ReceiveMessage, DeleteMessage, etc.)

SMS – Messages are sent to registered phone numbers as SMS text messages

SNS Supported Endpoints

Email Notifications
- SNS provides the ability to send Email notifications

Mobile Push Notifications
- SNS provides an ability to send push notification messages directly to apps on mobile devices. Push notification messages sent to a mobile endpoint can appear in the mobile app as message alerts, badge updates, or even sound alerts
- Supported push notification services
  - Amazon Device Messaging (ADM)
  - Apple Push Notification Service (APNS)
  - Google Cloud Messaging (GCM)
  - Windows Push Notification Service (WNS) for Windows 8+ and Windows Phone 8.1+
  - Microsoft Push Notification Service (MPNS) for Windows Phone 7+
  - Baidu Cloud Push for Android devices in China

SQS Queues
- SNS with SQS provides the ability for messages to be delivered to applications that require immediate notification of an event, and also persist in an SQS queue for other applications to process at a later time
- SNS allows applications to send time-critical messages to multiple subscribers through a “push” mechanism, eliminating the need to periodically check or “poll” for updates.
- SQS can be used by distributed applications to exchange messages through a polling model, and can be used to decouple sending and receiving components, without requiring each component to be concurrently available.
SMS Notifications
- SNS provides the ability to send and receive Short Message Service (SMS) notifications to SMS-enabled mobile phones and smart phones

HTTP/HTTPS Endpoints
- SNS provides the ability to send notification messages to one or more HTTP or HTTPS endpoints.When you subscribe an endpoint to a topic, you can publish a notification to the topic and Amazon SNS sends an HTTP POST request delivering the contents of the notification to the subscribed endpoint
Lambda
- SNS and Lambda are integrated so Lambda functions can be invoked with SNS notifications.
- When a message is published to an SNS topic that has a Lambda function subscribed to it, the Lambda function is invoked with the payload of the published message
Kinesis Data Firehose
- Deliver events to delivery streams for archiving and analysis purposes.
- Through delivery streams, events can be delivered to AWS destinations like S3, Redshift, and OpenSearch Service, or to third-party destinations such as Datadog, New Relic, MongoDB, and Splunk.

AWS Certification Exam Practice Questions

Which of the following notification endpoints or clients does Amazon Simple Notification Service support? Choose 2 answers
1. Email
2. CloudFront distribution
3. File Transfer Protocol
4. Short Message Service
5. Simple Network Management Protocol

What happens when you create a topic on Amazon SNS?
1. The topic is created, and it has the name you specified for it.
2. An ARN (Amazon Resource Name) is created
3. You can create a topic on Amazon SQS, not on Amazon SNS.
4. This question doesn’t make sense.
A user has deployed an application on his private cloud. The user is using his own monitoring tool. He wants to configure that whenever there is an error, the monitoring tool should notify him via SMS. Which of the below mentioned AWS services will help in this scenario?
1. None because the user infrastructure is in the private cloud/
2. AWS SNS
3. AWS SES
4. AWS SMS
A user wants to make so that whenever the CPU utilization of the AWS EC2 instance is above 90%, the redlight of his bedroom turns on. Which of the below mentioned AWS services is helpful for this purpose?
1. AWS CloudWatch + AWS SES
2. AWS CloudWatch + AWS SNS
3. It is not possible to configure the light with the AWS infrastructure services
4. AWS CloudWatch and a dedicated software turning on the light

A user is trying to understand AWS SNS. To which of the below mentioned end points is SNS unable to send a notification?
1. Email JSON
2. HTTP
3. AWS SQS
4. AWS SES
A user is running a webserver on EC2. The user wants to receive the SMS when the EC2 instance utilization is above the threshold limit. Which AWS services should the user configure in this case?
1. AWS CloudWatch + AWS SES
2. AWS CloudWatch + AWS SNS
3. AWS CloudWatch + AWS SQS
4. AWS EC2 + AWS CloudWatch
A user is planning to host a mobile game on EC2 which sends notifications to active users on either high score or the addition of new features. The user should get this notification when he is online on his mobile device. Which of the below mentioned AWS services can help achieve this functionality?
1. AWS Simple Notification Service
2. AWS Simple Queue Service
3. AWS Mobile Communication Service
4. AWS Simple Email Service

You are providing AWS consulting service for a company developing a new mobile application that will be leveraging amazon SNS push for push notifications. In order to send direct notification messages to individual devices each device registration identifier or token needs to be registered with SNS, however the developers are not sure of the best way to do this. You advise them to: –
1. Bulk upload the device tokens contained in a CSV file via the AWS Management Console
2. Let the push notification service (e.g. Amazon Device messaging) handle the registration
3. Implement a token vending service to handle the registration
4. Call the CreatePlatformEndpoint API function to register multiple device tokens. (Refer documentation)
A company is running a batch analysis every hour on their main transactional DB running on an RDS MySQL instance to populate their central Data Warehouse running on Redshift. During the execution of the batch their transactional applications are very slow. When the batch completes they need to update the top management dashboard with the new data. The dashboard is produced by another system running on-premises that is currently started when a manually-sent email notifies that an update is required The on-premises system cannot be modified because is managed by another team. How would you optimize this scenario to solve performance issues and automate the process as much as possible?
1. Replace RDS with Redshift for the batch analysis and SNS to notify the on-premises system to update the dashboard
2. Replace RDS with Redshift for the batch analysis and SQS to send a message to the on-premises system to update the dashboard
3. Create an RDS Read Replica for the batch analysis and SNS to notify me on-premises system to update the dashboard
4. Create an RDS Read Replica for the batch analysis and SQS to send a message to the on-premises system to update the dashboard.
Which of the following are valid SNS delivery transports? Choose 2 answers.
1. HTTP
2. UDP
3. SMS
4. DynamoDB
5. Named Pipes
What is the format of structured notification messages sent by Amazon SNS?
1. An XML object containing MessageId, UnsubscribeURL, Subject, Message and other values
2. An JSON object containing MessageId, DuplicateFlag, Message and other values
3. An XML object containing MessageId, DuplicateFlag, Message and other values
4. An JSON object containing MessageId, unsubscribeURL, Subject, Message and other values

Which of the following are valid arguments for an SNS Publish request? Choose 3 answers.
1. TopicAm
2. Subject
3. Destination
4. Format
5. Message
6. Language

References

Amazon_SNS – Developer Guide

AWS Migration Hub

December 30, 2022 ~ Last updated on : December 30, 2022 ~ jayendrapatil

AWS Migration Hub

AWS Migration Hub provides a centralized, single place to discover the existing servers, plan migrations, and track the status of each application migration.

provides visibility into the application portfolio and streamlines planning and tracking.
helps visualize the connections and the status of the migrating servers and databases, regardless of which migration tool is used.

stores all the data in the selected Home Region and provides a single repository of discovery and migration planning information for the entire portfolio and a single view of migrations into multiple AWS Regions.
helps track the status of the migrations in all AWS Regions, provided the migration tools are available in that Region.
helps understand the environment by letting you explore information collected by AWS discovery tools and stored in the AWS Application Discovery Service’s repository.

supports migration status updates from the following tools:
- AWS Application Migration Service
- AWS Server Migration Service
- AWS Database Migration Service – DMS
migration tools send migration status to the selected Home Region
supports EC2 instance recommendations, that provide you with the ability to estimate the cost of running the existing servers in AWS.

supports Strategy Recommendations, that help easily build a migration and modernization strategy for the applications running on-premises or in AWS.

Migration Hub’s Strategy Recommendations

AWS Migration Hub’s Strategy Recommendations help easily build a migration and modernization strategy for the applications running on-premises or in AWS.

Strategy Recommendations provides guidance on the strategy and tools that help you migrate and modernize at scale.
Strategy Recommendations supports analysis for potential rehost (EC2) and replatform (managed environments such as RDS and Elastic BeanStalk, Containers, and OS upgrades) options for applications running on Windows Server 2003 or above or a wide variety of Linux distributions, including Ubuntu, RedHat, Oracle Linux, Debian, and Fedora.
Strategy Recommendations offers additional refactor analysis for custom applications written in C# and Java, and licensed databases (such as Microsoft SQL Server and Oracle).

EC2 Instance Recommendations

EC2 instance recommendations help analyze the data collected from each on-premises server, including server specification, CPU, and memory utilization, to recommend the most cost-effective, least expensive EC2 instance required to run the on-premises workload.
EC2 instance recommendations can be fine-tuned by specifying preferences for AWS purchasing options, AWS Region, EC2 instance type exclusions, and CPU/RAM utilization metric (average, peak, or percentile).

AWS Certification Exam Practice Questions

A company wants to migrate its on-premises data center to the AWS Cloud. This includes thousands of virtualized Linux and Microsoft Windows servers, SAN storage, Java and PHP applications with MYSQL, and Oracle databases. There are many department services hosted either in the same data center or externally.
The technical documentation is incomplete and outdated. A solutions architect needs to understand the current environment and estimate the cloud resource costs after the migration.
Which tools or services should be used to plan the cloud migration (Choose TWO.)
1. AWS Application Discovery Service
2. AWS SMS
3. AWS X-Ray
4. Amazon Inspector
5. AWS Migration Hub

References

AWS_Migration_Hub

AWS Cloud Migration Services

December 29, 2022 ~ Last updated on : December 30, 2022 ~ jayendrapatil ~ 6 Comments

AWS Cloud Migration Services

AWS Cloud Migration services help to address a lot of common use cases such as
- cloud migration,
- disaster recovery,
- data center decommission, and
- content distribution.
For migrating data from on-premises to AWS, the major aspect for consideration are
- amount of data and network speed
- data security in transit
- existing application knowledge for recreation

Application & Database Cloud Migration Services

AWS Migration Hub

provides a centralized, single place to discover the existing servers, plan migrations, and track the status of each application migration.
provides visibility into the application portfolio and streamlines planning and tracking.
helps visualize the connections and the status of the migrating servers and databases, regardless of which migration tool is used.

stores all the data in the selected Home Region and provides a single repository of discovery and migration planning information for the entire portfolio and a single view of migrations into multiple AWS Regions.
helps track the status of the migrations in all AWS Regions, provided the migration tools are available in that Region.
helps understand the environment by letting you explore information collected by AWS discovery tools and stored in the AWS Application Discovery Service’s repository.

supports migration status updates from the following tools:
- AWS Application Migration Service
- AWS Server Migration Service
- AWS Database Migration Service – DMS
migration tools send migration status to the selected Home Region
supports EC2 instance recommendations, that provide you with the ability to estimate the cost of running the existing servers in AWS.

supports Strategy Recommendations, that help easily build a migration and modernization strategy for the applications running on-premises or in AWS.

AWS Application Discovery Service

AWS Application Discovery Service helps plan migration to the AWS cloud by collecting usage and configuration data about the on-premises servers.

helps enterprises obtain a snapshot of the current state of their data center servers by collecting server specification information, hardware configuration, performance data, details of running processes, and network connections
is integrated with AWS Migration Hub,
- which simplifies migration tracking as it aggregates migration status information into a single console.
- can help view the discovered servers, group them into applications, and then track the migration status of each application.
discovered data for all the regions is stored in the AWS Migration Hub home Region.
The data can be exported for analysis in Microsoft Excel or AWS analysis tools such as Amazon Athena and Amazon QuickSight.

supports both agent and agentless-based on-premises tooling, in addition to file-based import for performing discovery and collecting data about the on-premises servers.

AWS Server Migration Service (SMS)

is an agentless service that makes it easier and faster to migrate thousands of on-premises workloads to AWS.
helps automate, schedule, and track incremental replications of live server volumes, making it easier to coordinate large-scale server migrations.

currently supports migration of virtual machines from VMware vSphere, Windows Hyper-V and Azure VM to AWS
supports migrating Windows Server 2003, 2008, 2012, and 2016, and Windows 7, 8, and 10; Red Hat Enterprise Linux (RHEL), SUSE/SLES, CentOS, Ubuntu, Oracle Linux, Fedora, and Debian Linux OS
replicates each server volume, which is saved as a new AMI, which can be launched as an EC2 instance

is a significant enhancement of EC2 VM Import/Export service
is used to Re-host

AWS Database Migration Service (DMS)

helps migrate databases to AWS quickly and securely.

source database remains fully operational during the migration, minimizing downtime to applications that rely on the database.
supports homogeneous migrations such as Oracle to Oracle, as well as heterogeneous migrations between different database platforms, such as Oracle or Microsoft SQL Server to Amazon Aurora.
monitors for replication tasks, network or host failures, and automatically provisions a host replacement in case of failures that can’t be repaired

supports both one-time data migration into RDS and EC2-based databases as well as for continuous data replication
supports continuous replication of the data with high availability and consolidate databases into a petabyte-scale data warehouse by streaming data to Amazon Redshift and Amazon S3
provides free AWS Schema Conversion Tool (SCT) that automates the conversion of Oracle PL/SQL and SQL Server T-SQL code to equivalent code in the Amazon Aurora / MySQL dialect of SQL or the equivalent PL/pgSQL code in PostgreSQL

AWS EC2 VM Import/Export

allows easy import of virtual machine images from existing environment to EC2 instances and export them back to on-premises environment
allows leveraging of existing investments in the virtual machines, built to meet compliance requirements, configuration management and IT security by bringing those virtual machines into EC2 as ready-to-use instances

Common usages include
- Migrate Existing Applications and Workloads to EC2, allowing preserving of the software and settings configured in the existing VMs.
- Copy Your VM Image Catalog to EC2
- Create a Disaster Recovery Repository for your VM images

Data Transfer Services

VPN

connection utilizes IPSec to establish encrypted network connectivity between on-premises network and VPC over the Internet.
connections can be configured in minutes and a good solution for an immediate need, have low to modest bandwidth requirements, and can tolerate the inherent variability in Internet-based connectivity.

still requires internet and be configured using VGW and CGW

AWS Direct Connect

provides a dedicated physical connection between the corporate network and AWS Direct Connect location with no data transfer over the Internet.
helps bypass Internet service providers (ISPs) in the network path

helps reduce network costs, increase bandwidth throughput, and provide a more consistent network experience than with Internet-based connection
takes time to setup and involves third parties
are not redundant and would need another direct connect connection or a VPN connection

Security
- provides a dedicated physical connection without internet
- For additional security can be used with VPN

AWS Import/Export (upgraded to Snowball)

accelerates moving large amounts of data into and out of AWS using secure Snowball appliances
AWS transfers the data directly onto and off of the storage devices using Amazon’s high-speed internal network, bypassing the Internet
Data Migration
- for significant data size, AWS Import/Export is faster than Internet transfer is and more cost-effective than upgrading the connectivity
- if loading the data over the Internet would take a week or more, AWS Import/Export should be considered
- data from appliances can be imported to S3, Glacier and EBS volumes and exported from S3
- not suitable for applications that cannot tolerate offline transfer time
Security
- Snowball uses an industry-standard Trusted Platform Module (TPM) that has a dedicated processor designed to detect any unauthorized modifications to the hardware, firmware, or software to physically secure the AWS Snowball device.

Snow Family

AWS Snowball
- is a petabyte-scale data transfer service built around a secure suitcase-sized device that moves data into and out of the AWS Cloud quickly and efficiently.
- transfers the data to S3 bucket
- transfer times are about a week from start to finish.
- are commonly used to ship terabytes or petabytes of analytics data, healthcare and life sciences data, video libraries, image repositories, backups, and archives as part of data center shutdown, tape replacement, or application migration projects.
AWS Snowball Edge devices
- contain slightly larger capacity and an embedded computing platform that helps perform simple processing tasks.
- can be rack shelved and may also be clustered together, making it simpler to collect and store data in extremely remote locations.
- commonly used in environments with intermittent connectivity (such as manufacturing, industrial, and transportation); or in extremely remote locations (such as military or maritime operations) before shipping them back to AWS data centers.
- delivers serverless computing applications at the network edge using AWS Greengrass and Lambda functions.
- common use cases include capturing IoT sensor streams, on-the-fly media transcoding, image compression, metrics aggregation and industrial control signaling and alarming.
AWS Snowmobile
- moves up to 100PB of data (equivalent to 1,250 AWS Snowball devices) in a 45-foot long ruggedized shipping container and is ideal for multi-petabyte or Exabyte-scale digital media migrations and datacenter shutdowns.
- arrives at the customer site and appears as a network-attached data store for more secure, high-speed data transfer. After data is transferred to Snowmobile, it is driven back to an AWS Region where the data is loaded into S3.
- is tamper-resistant, waterproof, and temperature controlled with multiple layers of logical and physical security — including encryption, fire suppression, dedicated security personnel, GPS tracking, alarm monitoring, 24/7 video surveillance, and an escort security vehicle during transit.

AWS Storage Gateway

connects an on-premises software appliance with cloud-based storage to provide seamless and secure integration between an organization’s on-premises IT environment and the AWS storage infrastructure
provides low-latency performance by maintaining frequently accessed data on-premises while securely storing all of the data encrypted in S3 or Glacier.
for disaster recovery scenarios, Storage Gateway, together with EC2, can serve as a cloud-hosted solution that mirrors the entire production environment

Data Migration
- with gateway-cached volumes, S3 can be used to hold primary data while frequently accessed data is cached locally for faster access reducing the need to scale on premises storage infrastructure
- with gateway-stored volumes, entire data is stored locally while asynchronously backing up data to S3
- with gateway-VTL, offline data archiving can be performed by presenting existing backup application with an iSCSI-based VTL consisting of a virtual media changer and virtual tape drives
Security
- Encrypts all data in transit to and from AWS by using SSL/TLS.
- All data in AWS Storage Gateway is encrypted at rest using AES-256.
- Authentication between the gateway and iSCSI initiators can be secured by using Challenge-Handshake Authentication Protocol (CHAP).

Simple Storage Service – S3

Data Transfer
- Files up to 5GB can be transferred using single operation
- Multipart uploads can be used to upload files up to 5 TB and speed up data uploads by dividing the file into multiple parts
- transfer rate still limited by the network speed

Security
- Data in transit can be secured by using SSL/TLS or client-side encryption.
- Encrypt data at-rest by performing server-side encryption using Amazon S3-Managed Keys (SSE-S3), AWS Key Management Service (KMS)-Managed Keys (SSE-KMS), or Customer Provided Keys (SSE-C). Or by performing client-side encryption using AWS KMS–Managed Customer Master Key (CMK) or Client-Side Master Key.

AWS Certification Exam Practice Questions

Questions are collected from Internet and the answers are marked as per my knowledge and understanding (which might differ with yours).
AWS services are updated everyday and both the answers and questions might be outdated soon, so research accordingly.
AWS exam questions are not updated to keep up the pace with AWS updates, so even if the underlying feature has changed the question might not be updated

Open to further feedback, discussion and correction.

Your must architect the migration of a web application to AWS. The application consists of Linux web servers running a custom web server. You are required to save the logs generated from the application to a durable location. What options could you select to migrate the application to AWS? (Choose 2)
1. Create an AWS Elastic Beanstalk application using the custom web server platform. Specify the web server executable and the application project and source files. Enable log file rotation to Amazon Simple Storage Service (S3). (EB does not work with Custom server executable)
2. Create Dockerfile for the application. Create an AWS OpsWorks stack consisting of a custom layer. Create custom recipes to install Docker and to deploy your Docker container using the Dockerfile. Create custom recipes to install and configure the application to publish the logs to Amazon CloudWatch Logs (although this is one of the option, the last sentence mentions configure the application to push the logs to S3, which would need changes to application as it needs to use SDK or CLI)
3. Create Dockerfile for the application. Create an AWS OpsWorks stack consisting of a Docker layer that uses the Dockerfile. Create custom recipes to install and configure Amazon Kinesis to publish the logs into Amazon CloudWatch. (Kinesis not needed)
4. Create a Dockerfile for the application. Create an AWS Elastic Beanstalk application using the Docker platform and the Dockerfile. Enable logging the Docker configuration to automatically publish the application logs. Enable log file rotation to Amazon S3. (Use Docker configuration with awslogs and EB with Docker)
5. Use VM import/Export to import a virtual machine image of the server into AWS as an AMI. Create an Amazon Elastic Compute Cloud (EC2) instance from AMI, and install and configure the Amazon CloudWatch Logs agent. Create a new AMI from the instance. Create an AWS Elastic Beanstalk application using the AMI platform and the new AMI. (Use VM Import/Export to create AMI and CloudWatch logs agent to log)
Your company hosts an on-premises legacy engineering application with 900GB of data shared via a central file server. The engineering data consists of thousands of individual files ranging in size from megabytes to multiple gigabytes. Engineers typically modify 5-10 percent of the files a day. Your CTO would like to migrate this application to AWS, but only if the application can be migrated over the weekend to minimize user downtime. You calculate that it will take a minimum of 48 hours to transfer 900GB of data using your company’s existing 45-Mbps Internet connection. After replicating the application’s environment in AWS, which option will allow you to move the application’s data to AWS without losing any data and within the given timeframe?
1. Copy the data to Amazon S3 using multiple threads and multi-part upload for large files over the weekend, and work in parallel with your developers to reconfigure the replicated application environment to leverage Amazon S3 to serve the engineering files. (Still limited by 45 Mbps speed with minimum 48 hours when utilized to max)
2. Sync the application data to Amazon S3 starting a week before the migration, on Friday morning perform a final sync, and copy the entire data set to your AWS file server after the sync completes. (Works best as the data changes can be propagated over the week and are fractional and downtime would be know)
3. Copy the application data to a 1-TB USB drive on Friday and immediately send overnight, with Saturday delivery, the USB drive to AWS Import/Export to be imported as an EBS volume, mount the resulting EBS volume to your AWS file server on Sunday. (Downtime is not known when the data upload would be done, although Amazon says the same day the package is received)
4. Leverage the AWS Storage Gateway to create a Gateway-Stored volume. On Friday copy the application data to the Storage Gateway volume. After the data has been copied, perform a snapshot of the volume and restore the volume as an EBS volume to be attached to your AWS file server on Sunday. (Still uses the internet)

You are tasked with moving a legacy application from a virtual machine running inside your datacenter to an Amazon VPC. Unfortunately this app requires access to a number of on-premises services and no one who configured the app still works for your company. Even worse there’s no documentation for it. What will allow the application running inside the VPC to reach back and access its internal dependencies without being reconfigured? (Choose 3 answers)
1. An AWS Direct Connect link between the VPC and the network housing the internal services
2. An Internet Gateway to allow a VPN connection. (Virtual and Customer gateway is needed)
3. An Elastic IP address on the VPC instance
4. An IP address space that does not conflict with the one on-premises
5. Entries in Amazon Route 53 that allow the Instance to resolve its dependencies’ IP addresses
6. A VM Import of the current virtual machine
An enterprise runs 103 line-of-business applications on virtual machines in an on-premises data center. Many of the applications are simple PHP, Java, or Ruby web applications, are no longer actively developed, and serve little traffic. Which approach should be used to migrate these applications to AWS with the LOWEST infrastructure costs?
1. Deploy the applications to single-instance AWS Elastic Beanstalk environments without a load balancer.
2. Use AWS SMS to create AMIs for each virtual machine and run them in Amazon EC2.
3. Convert each application to a Docker image and deploy to a small Amazon ECS cluster behind an Application Load Balancer.
4. Use VM Import/Export to create AMIs for each virtual machine and run them in single-instance AWS Elastic Beanstalk environments by configuring a custom image.

References

AWS_Cloud_Migration_Services

AWS VPN

December 29, 2022 ~ Last updated on : December 29, 2022 ~ jayendrapatil ~ 21 Comments

AWS VPC VPN

AWS VPN connections are used to extend on-premises data centers to AWS.

VPN connections provide secure IPSec connections between the data center or branch office and the AWS resources.
AWS Site-to-Site VPN or AWS Hardware VPN or AWS Managed VPN
- Connectivity can be established by creating an IPSec, hardware VPN connection between the VPC and the remote network.
- On the AWS side of the VPN connection, a Virtual Private Gateway (VGW) provides two VPN endpoints for automatic failover.
- On the customer side, a customer gateway (CGW) needs to be configured, which is the physical device or software application on the remote side of the VPN connection

AWS Client VPN
- AWS Client VPN is a managed client-based VPN service that enables secure access to AWS resources and resources in the on-premises network.
AWS VPN CloudHub
- For more than one remote network e.g. multiple branch offices, multiple AWS hardware VPN connections can be created via the VPC to enable communication between these networks
AWS Software VPN
- A VPN connection can be created to the remote network by using an EC2 instance in the VPC that’s running a third-party software VPN appliance.
- AWS does not provide or maintain third-party software VPN appliances; however, there is a range of products provided by partners and open source communities.
AWS Direct Connect provides a dedicated private connection from a remote network to the VPC. Direct Connect can be combined with an AWS hardware VPN connection to create an IPsec-encrypted connection

VPN Components

Virtual Private Gateway – VGW
- A virtual private gateway is the VPN concentrator on the AWS side of the VPN connection
Customer Gateway – CGW
- A customer gateway is a physical device or software application on the customer side of the VPN connection.
- When a VPN connection is created, the VPN tunnel comes up when traffic is generated from the remote side of the VPN connection.
- By default, VGW is not the initiator; CGW must bring up the tunnels for the Site-to-Site VPN connection by generating traffic and initiating the Internet Key Exchange (IKE) negotiation process.
- If the VPN connection experiences a period of idle time, usually 10 seconds, depending on the configuration, the tunnel may go down. To prevent this, a network monitoring tool to generate keepalive pings; for e.g. by using IP SLA.
Transit Gateway
- A transit gateway is a transit hub that can be used to interconnect VPCs and on-premises networks.
- A Site-to-Site VPN connection on a transit gateway can support either IPv4 traffic or IPv6 traffic inside the VPN tunnels.
A Site-to-Site VPN connection offers two VPN tunnels between a VGW or a transit gateway on the AWS side, and a CGW (which represents a VPN device) on the remote (on-premises) side.

VPN Routing Options

For a VPN connection, the route table for the subnets should be updated with the type of routing (static or dynamic) that you plan to use.

Route tables determine where network traffic is directed. Traffic destined for the VPN connections must be routed to the virtual private gateway.
The type of routing can depend on the make and model of the CGW device
- Static Routing
  - If your device does not support BGP, specify static routing.
  - Using static routing, the routes (IP prefixes) can be specified that should be communicated to the virtual private gateway.
  - Devices that don’t support BGP may also perform health checks to assist failover to the second tunnel when needed.
- BGP Dynamic Routing
  - If the VPN device supports Border Gateway Protocol (BGP), specify dynamic routing with the VPN connection.
  - When using a BGP device, static routes need not be specified to the VPN connection because the device uses BGP for auto-discovery and to advertise its routes to the virtual private gateway.
  - BGP-capable devices are recommended as the BGP protocol offers robust liveness detection checks that can assist failover to the second VPN tunnel if the first tunnel goes down.
Only IP prefixes known to the virtual private gateway, either through BGP advertisement or static route entry, can receive traffic from the VPC.
Virtual private gateway does not route any other traffic destined outside of the advertised BGP, static route entries, or its attached VPC CIDR.

VPN Route Priority

Longest prefix match applies.
If the prefixes are the same, then the VGW prioritizes routes as follows, from most preferred to least preferred:
- BGP propagated routes from an AWS Direct Connect connection
- Manually added static routes for a Site-to-Site VPN connection
- BGP propagated routes from a Site-to-Site VPN connection
- Prefix with the shortest AS PATH is preferred for matching prefixes where each Site-to-Site VPN connection uses BGP
- Path with the lowest multi-exit discriminators (MEDs) value is preferred when the AS PATHs are the same length and if the first AS in the AS_SEQUENCE is the same across multiple paths.

VPN Limitations

supports only IPSec tunnel mode. Transport mode is currently not supported.
supports only one VGW can be attached to a VPC at a time.

does not support IPv6 traffic on a virtual private gateway.
does not support Path MTU Discovery.
does not support overlapping CIDR blocks for the networks. It is recommended to use non-overlapping CIDR blocks.

does not support transitive routing. So for traffic from on-premises to AWS via a virtual private gateway, it
- does not support Internet connectivity through Internet Gateway
- does not support Internet connectivity through NAT Gateway
- does not support VPC Peered resources access through VPC Peering
- does not support S3, DynamoDB access through VPC Gateway Endpoint
- However, Internet connectivity through NAT instance and VPC Interface Endpoint or PrivateLink services are accessible.

provides a bandwidth of 1.25 Gbps, currently.

VPN Monitoring

AWS Site-to-Site VPN automatically sends notifications to the AWS AWS Health Dashboard
AWS Site-to-Site VPN is integrated with CloudWatch with the following metrics available
- TunnelState
  - The state of the tunnels.
  - For static VPNs, 0 indicates DOWN and 1 indicates UP.
  - For BGP VPNs, 1 indicates ESTABLISHED and 0 is used for all other states.
  - For both types of VPNs, values between 0 and 1 indicate at least one tunnel is not UP.
- TunnelDataIn
  - The bytes received on the AWS side of the connection through the VPN tunnel from a customer gateway.
- TunnelDataOut
  - The bytes sent from the AWS side of the connection through the VPN tunnel to the customer gateway.

VPN Connection Redundancy

A VPN connection is used to connect the customer network to a VPC.
Each VPN connection has two tunnels to help ensure connectivity in case one of the VPN connections becomes unavailable, with each tunnel using a unique virtual private gateway public IP address.

Both tunnels should be configured for redundancy.
When one tunnel becomes unavailable, for e.g. down for maintenance, network traffic is automatically routed to the available tunnel for that specific VPN connection.
To protect against a loss of connectivity in case the customer gateway becomes unavailable, a second VPN connection can be set up to the VPC and virtual private gateway by using a second customer gateway.

Customer gateway IP address for the second VPN connection must be publicly accessible.
By using redundant VPN connections and CGWs, maintenance on one of the customer gateways can be performed while traffic continues to flow over the second customer gateway’s VPN connection.
Dynamically routed VPN connections using the Border Gateway Protocol (BGP) are recommended, if available, to exchange routing information between the customer gateways and the virtual private gateways.

Statically routed VPN connections require static routes for the network to be entered on the customer gateway side.
BGP-advertised and statically entered route information allow gateways on both sides to determine which tunnels are available and reroute traffic if a failure occurs.

Multiple Site-to-Site VPN Connections

VPC has an attached virtual private gateway, and the remote network includes a customer gateway, which must be configured to enable the
VPN connection.

Routing must be set up so that any traffic from the VPC bound for the remote network is routed to the virtual private gateway.
Each VPN has two tunnels associated with it that can be configured on the customer router, as is not a single point of failure
Multiple VPN connections to a single VPC can be created, and a second CGW can be configured to create a redundant connection to the same external location or to create VPN connections to multiple geographic locations.

VPN CloudHub

VPN CloudHub can be used to provide secure communication between multiple on-premises sites if you have multiple VPN connections
VPN CloudHub operates on a simple hub-and-spoke model using a Virtual Private gateway in a detached mode that can be used without a VPC.
Design is suitable for customers with multiple branch offices and existing
Internet connections who’d like to implement a convenient, potentially low-cost hub-and-spoke model for primary or backup connectivity between these remote offices

VPN CloudHub architecture with blue dashed lines indicates network
traffic between remote sites being routed over their VPN connections.
AWS VPN CloudHub requires a virtual private gateway with multiple customer gateways.

Each customer gateway must use a unique Border Gateway Protocol (BGP) Autonomous System Number (ASN)
Customer gateways advertise the appropriate routes (BGP prefixes) over their VPN connections.
Routing advertisements are received and re-advertised to each BGP peer, enabling each site to send data to and receive data from the other sites.

Routes for each spoke must have unique ASNs and the sites must not have overlapping IP ranges.
Each site can also send and receive data from the VPC as if they were using a standard VPN connection.
Sites that use AWS Direct Connect connections to the virtual private gateway can also be part of the AWS VPN CloudHub.

To configure the AWS VPN CloudHub,
- multiple customer gateways can be created, each with the unique public IP address of the gateway and the ASN.
- a VPN connection can be created from each customer gateway to a common virtual private gateway.
- each VPN connection must advertise its specific BGP routes. This is done using the network statements in the VPN configuration files for the VPN connection.

VPN vs Direct Connect

AWS Certification Exam Practice Questions

You have in total 5 offices, and the entire employee-related information is stored under AWS VPC instances. Now all the offices want to connect the instances in VPC using VPN. Which of the below help you to implement this?
1. you can have redundant customer gateways between your data center and your VPC
2. you can have multiple locations connected to the AWS VPN CloudHub
3. You have to define 5 different static IP addresses in route table.
4. 1 and 2
5. 1,2 and 3

You have in total of 15 offices, and the entire employee-related information is stored under AWS VPC instances. Now all the offices want to connect the instances in VPC using VPN. What problem do you see in this scenario?
1. You can not create more than 1 VPN connections with single VPC (Can be created)
2. You can not create more than 10 VPN connections with single VPC (soft limit can be extended)
3. When you create multiple VPN connections, the virtual private gateway can not sends network traffic to the appropriate VPN connection using statically assigned routes. (Can route the traffic to correct connection)
4. Statically assigned routes cannot be configured in case of more than 1 VPN with the virtual private gateway. (can be configured)
5. None of above

You have been asked to virtually extend two existing data centers into AWS to support a highly available application that depends on existing, on-premises resources located in multiple data centers and static content that is served from an Amazon Simple Storage Service (S3) bucket. Your design currently includes a dual-tunnel VPN connection between your CGW and VGW. Which component of your architecture represents a potential single point of failure that you should consider changing to make the solution more highly available?
1. Add another VGW in a different Availability Zone and create another dual-tunnel VPN connection.
2. Add another CGW in a different data center and create another dual-tunnel VPN connection. (Refer link)
3. Add a second VGW in a different Availability Zone, and a CGW in a different data center, and create another dual-tunnel.
4. No changes are necessary: the network architecture is currently highly available.
You are designing network connectivity for your fat client application. The application is designed for business travelers who must be able to connect to it from their hotel rooms, cafes, public Wi-Fi hotspots, and elsewhere on the Internet. You do not want to publish the application on the Internet. Which network design meets the above requirements while minimizing deployment and operational costs? [PROFESSIONAL]
1. Implement AWS Direct Connect, and create a private interface to your VPC. Create a public subnet and place your application servers in it. (High Cost and does not minimize deployment)
2. Implement Elastic Load Balancing with an SSL listener that terminates the back-end connection to the application. (Needs to be published to internet)
3. Configure an IPsec VPN connection, and provide the users with the configuration details. Create a public subnet in your VPC, and place your application servers in it. (Instances still in public subnet are internet accessible)
4. Configure an SSL VPN solution in a public subnet of your VPC, then install and configure SSL VPN client software on all user computers. Create a private subnet in your VPC and place your application servers in it. (Cost effective and can be in private subnet as well)
You are designing a connectivity solution between on-premises infrastructure and Amazon VPC Your server’s on-premises will De communicating with your VPC instances You will De establishing IPSec tunnels over the internet You will be using VPN gateways and terminating the IPsec tunnels on AWS-supported customer gateways. Which of the following objectives would you achieve by implementing an IPSec tunnel as outlined above? (Choose 4 answers) [PROFESSIONAL]
1. End-to-end protection of data in transit
2. End-to-end Identity authentication
3. Data encryption across the Internet
4. Protection of data in transit over the Internet
5. Peer identity authentication between VPN gateway and customer gateway
6. Data integrity protection across the Internet
A development team that is currently doing a nightly six-hour build which is lengthening over time on-premises with a large and mostly under utilized server would like to transition to a continuous integration model of development on AWS with multiple builds triggered within the same day. However, they are concerned about cost, security and how to integrate with existing on-premises applications such as their LDAP and email servers, which cannot move off-premises. The development environment needs a source code repository; a project management system with a MySQL database resources for performing the builds and a storage location for QA to pick up builds from. What AWS services combination would you recommend to meet the development team’s requirements? [PROFESSIONAL]
1. A Bastion host Amazon EC2 instance running a VPN server for access from on-premises, Amazon EC2 for the source code repository with attached Amazon EBS volumes, Amazon EC2 and Amazon RDS MySQL for the project management system, EIP for the source code repository and project management system, Amazon SQL for a build queue, An Amazon Auto Scaling group of Amazon EC2 instances for performing builds and Amazon Simple Email Service for sending the build output. (Bastion is not for VPN connectivity also SES should not be used)
2. An AWS Storage Gateway for connecting on-premises software applications with cloud-based storage securely, Amazon EC2 for the resource code repository with attached Amazon EBS volumes, Amazon EC2 and Amazon RDS MySQL for the project management system, EIPs for the source code repository and project management system, Amazon Simple Notification Service for a notification initiated build, An Auto Scaling group of Amazon EC2 instances for performing builds and Amazon S3 for the build output. (Storage Gateway does provide secure connectivity but still needs VPN. SNS alone cannot handle builds)
3. An AWS Storage Gateway for connecting on-premises software applications with cloud-based storage securely, Amazon EC2 for the resource code repository with attached Amazon EBS volumes, Amazon EC2 and Amazon RDS MySQL for the project management system, EIPs for the source code repository and project management system, Amazon SQS for a build queue, An Amazon Elastic Map Reduce (EMR) cluster of Amazon EC2 instances for performing builds and Amazon CloudFront for the build output. (Storage Gateway does not provide secure connectivity, still needs VPN. EMR is not ideal for performing builds as it needs normal EC2 instances)
4. A VPC with a VPN Gateway back to their on-premises servers, Amazon EC2 for the source-code repository with attached Amazon EBS volumes, Amazon EC2 and Amazon RDS MySQL for the project management system, EIPs for the source code repository and project management system, SQS for a build queue, An Auto Scaling group of EC2 instances for performing builds and S3 for the build output. (VPN gateway is required for secure connectivity. SQS for build queue and EC2 for builds)

References

AWS VPC VPN Connections User Guide

AWS VPC Interface Endpoints – PrivateLink

December 29, 2022 ~ Last updated on : April 29, 2023 ~ jayendrapatil

VPC Interface Endpoints – PrivateLink

VPC Interface endpoints enable connectivity to services powered by AWS PrivateLink.

Services include AWS services like CloudTrail, CloudWatch, etc., services hosted by other AWS customers and partners in their own VPCs (referred to as endpoint services), and supported AWS Marketplace partner services.
VPC Interface Endpoints only allow traffic from VPC resources to the endpoints and not vice versa

PrivateLink endpoints can be accessed across both intra- and inter-region VPC peering connections, Direct Connect, and VPN connections.
VPC Interface Endpoints, by default, have an address like vpce-svc-01234567890abcdef.us-east-1.vpce.amazonaws.com which needs application changes to point to the service.
Private DNS name feature allows consumers to use AWS service public default DNS names which would point to the private VPC endpoint service.

Interface Endpoints can be used to create custom applications in VPC and configure them as an AWS PrivateLink-powered service (referred to as an endpoint service) exposed through a Network Load Balancer.
Custom applications can be hosted within AWS or on-premises (via Direct Connect or VPN)

Interface Endpoints Configuration

Create an interface endpoint, and provide the name of the AWS service, endpoint service, or AWS Marketplace service

Choose the subnet to use the interface endpoint by creating an endpoint network interface.
An endpoint network interface is assigned a private IP address from the IP address range of the subnet and keeps this IP address until the interface endpoint is deleted
A private IP address also ensures the traffic remains private without any changes to the route table.

VPC Endpoint policy

VPC Endpoint policy is an IAM resource policy attached to an endpoint for controlling access from the endpoint to the specified service.
Endpoint policy, by default, allows full access to any user or service within the VPC, using credentials from any AWS account to any S3 resource; including S3 resources for an AWS account other than the account with which the VPC is associated
Endpoint policy does not override or replace IAM user policies or service-specific policies (such as S3 bucket policies).

Endpoint policy can be used to restrict which specific resources can be accessed using the VPC Endpoint.

{
  "Sid": "AccessToSpecificBucket",
  "Effect": "Allow",
  "Principal": "*",
  "Action": [
     "s3:ListBucket",
     "s3:GetObject",
  ],
  "Resource": [
     "arn:aws:s3:::example-bucket",
     "arn:aws:s3:::example-bucket/*"
  ]
}

{

"Sid": "AccessToSpecificBucket",

"Effect": "Allow",

"Principal": "*",

"Action": [

"s3:ListBucket",

"s3:GetObject",

"Resource": [

"arn:aws:s3:::example-bucket",

"arn:aws:s3:::example-bucket/*"

]

}

Interface Endpoint Limitations

For each interface endpoint, only one subnet per AZ can be selected.
Interface Endpoint supports TCP traffic only.

Endpoints are supported within the same region only.
Endpoints support IPv4 traffic only.
Each interface endpoint can support a bandwidth of up to 10 Gbps per AZ, by default, and automatically scales to 40 Gbps. Additional capacity may be added by reaching out to AWS support.

NACLs for the subnet can restrict traffic, and needs to be configured properly
Endpoints cannot be transferred from one VPC to another, or from one service to another.

AWS Certification Exam Practice Questions

An application server needs to be in a private subnet without access to the internet. The solution must retrieve and upload data to an Amazon Kinesis. How should a Solutions Architect design a solution to meet these requirements?
1. Use Amazon VPC Gateway endpoints
2. Use a NAT Gateway
3. Use Amazon VPC Interface endpoints
4. Use a private Amazon Kinesis Data Stream

References

AWS_PrivateLink

AWS VPC Gateway Endpoints

December 29, 2022 ~ Last updated on : April 29, 2023 ~ jayendrapatil

AWS VPC Gateway Endpoints

A VPC Gateway Endpoint is a gateway that is a target for a specified route in the route table, used for traffic destined for a supported AWS service.

VPC Gateway Endpoints currently supports S3 and DynamoDB services
VPC Gateway Endpoints do not require an Internet gateway or a NAT device for the VPC.

Gateway endpoints do not enable AWS PrivateLink.
VPC Endpoint policy and Resource-based policies can be used for fine-grained access control.

Gateway Endpoint Configuration

Endpoint requires the VPC and the service to be accessed via the endpoint.
The endpoint needs to be associated with the Route table and the route table cannot be modified to remove the route entry. It can only be deleted by removing the Endpoint association with the Route table

A route is automatically added to the Route table with a destination that specifies the prefix list of service and the target with the endpoint id for e.g. A rule with destination pl-68a54001 (com.amazonaws.us-west-2.s3) and a target with this endpoints’ ID (e.g. vpce-12345678) will be added to the route tables
Access to the resources in other services can be controlled by endpoint policies
Security groups need to be modified to allow outbound traffic from the VPC to the service that is specified in the endpoint. Use the service prefix list ID for e.g. com.amazonaws.us-east-1.s3 as the destination in the outbound rule

Multiple endpoints can be created in a single VPC, for e.g., to multiple services.
Multiple endpoints can be created for the same service but in different route tables.
Multiple endpoints to the same service CAN NOT be specified in a single route table

Gateway Endpoint Limitations

are regional and supported within the same Region only.
cannot be created between a VPC and an AWS service in a different region.
support IPv4 traffic only.

cannot be transferred from one VPC to another, or from one service to another service.
connections cannot be extended out of a VPC i.e. resources across the VPN, VPC peering, Direct Connect connection cannot use the endpoint.

VPC Endpoint policy

VPC Endpoint policy is an IAM resource policy attached to an endpoint for controlling access from the endpoint to the specified service.

Endpoint policy, by default, allows full access to any user or service within the VPC, using credentials from any AWS account to any S3 resource; including S3 resources for an AWS account other than the account with which the VPC is associated
Endpoint policy does not override or replace IAM user policies or service-specific policies (such as S3 bucket policies).
Endpoint policy can be used to restrict which specific resources can be accessed using the VPC Endpoint.

{
  "Sid": "AccessToSpecificBucket",
  "Effect": "Allow",
  "Principal": "*",
  "Action": [
     "s3:ListBucket",
     "s3:GetObject",
  ],
  "Resource": [
     "arn:aws:s3:::example-bucket",
     "arn:aws:s3:::example-bucket/*"
  ]
}

{

"Sid": "AccessToSpecificBucket",

"Effect": "Allow",

"Principal": "*",

"Action": [

"s3:ListBucket",

"s3:GetObject",

"Resource": [

"arn:aws:s3:::example-bucket",

"arn:aws:s3:::example-bucket/*"

]

}

S3 Bucket Policies

IAM policy or bucket policy can’t be used to allow access from a VPC IPv4 CIDR range as the VPC CIDR blocks can be overlapping or identical, which might lead to unexpected results.
aws:SourceIp condition can’t be used in the IAM policies for requests to S3 through a VPC endpoint.
S3 Bucket Policies can be used to restrict access through the VPC endpoint only.

{
  "Version": "2012-10-17",
  "Id": "Access-to-bucket-using-specific-endpoint",
  "Statement": [
    {
      "Sid": "Access-to-specific-VPCE-only",
      "Effect": "Deny",
      "Principal": "*",
      "Action": "s3:*",
      "Resource": ["arn:aws:s3:::example_bucket",
                   "arn:aws:s3:::example_bucket/*"],
      "Condition": {
        "StringNotEquals": {
          "aws:sourceVpce": "vpce-1a2b3c4d"
        }
      }
    }
  ]
}

{

"Version": "2012-10-17",

"Id": "Access-to-bucket-using-specific-endpoint",

"Statement": [

{

"Sid": "Access-to-specific-VPCE-only",

"Effect": "Deny",

"Principal": "*",

"Action": "s3:*",

"Resource": ["arn:aws:s3:::example_bucket",

"arn:aws:s3:::example_bucket/*"],

"Condition": {

"StringNotEquals": {

"aws:sourceVpce": "vpce-1a2b3c4d"

}

]

}

VPC Gateway Endpoint Troubleshooting

Verify the services are within the same region.
DNS resolution must be enabled in the VPC
Route table should have a route to S3 using the gateway VPC endpoint.

Security groups should have outbound traffic allowed VPC endpoint.
NACLs should allow inbound and outbound traffic.
Gateway Endpoint Policy should define access to the resource

Resource-based policies like the S3 bucket policy should allow access to the VPC endpoint or the VPC.

AWS Certification Exam Practice Questions

You have an application running on an Amazon EC2 instance that uploads 10 GB video objects to amazon S3. Video uploads are taking longer than expected inspite of using multipart upload cause of internet bandwidth, resulting in poor application performance. Which action can help improve the upload performance?
1. Apply an Amazon S3 bucket policy
2. Use Amazon EBS provisioned IOPS
3. Use VPC endpoints for S3
4. Request a service limit increase

What are the services supported by VPC endpoints, using Gateway endpoint type? Choose 2 answers
1. Amazon S3
2. Amazon EFS
3. Amazon DynamoDB
4. Amazon Glacier
5. Amazon SQS

An application running on EC2 instances processes sensitive information stored on Amazon S3. The information is accessed over the Internet. The security team is concerned that the Internet connectivity to Amazon S3 is a security risk. Which solution will resolve the security concern?
1. Access the data through an Internet Gateway.
2. Access the data through a VPN connection.
3. Access the data through a NAT Gateway.
4. Access the data through a VPC endpoint for Amazon S3.

References

AWS_VPC_Gateway_Endpoints