Managing AWS CloudShell access and usage with IAM policies - AWS CloudShell

Managing AWS CloudShell access and usage with IAM policies

With the access management resources that can be provided by AWS Identity and Access Management (IAM), administrators can grant permissions to IAM users. That way, these users can access AWS CloudShell and use the environment's features. Administrators can also create policies that specify at a granular level what actions those users can perform with the shell environment.

The quickest way for an administrator to grant access to users is through an AWS managed policy. An AWS managed policy is a standalone policy that's created and administered by AWS. The following AWS managed policy for AWS CloudShell can be attached to IAM identities:

  • AWSCloudShellFullAccess: Grants permission to use AWS CloudShell with full access to all features.

The AWSCloudShellFullAccess policy uses the wildcard (*) character to give the IAM identity (user, role, or group) full access to CloudShell and features. For more information on this policy, see AWSCloudShellFullAccess in the AWS Managed Policy User Guide.

Note

IAM identities with the following AWS managed policies can also launch CloudShell. However, these policies provide extensive permissions. So, we recommend that you only grant these policies if they're essential for an IAM user's job role.

  • Administrator: Provides IAM users with full access and allows them to delegate permissions to every service and resource in AWS.

  • Developer power user: Enables IAM users to perform application development tasks and create and configure resources and services that support AWS aware application development.

For more information about attaching managed policies, see Adding IAM identity permissions (console) in the IAM User Guide.

Managing allowable actions in AWS CloudShell using custom policies

To manage the actions that an IAM user can perform with CloudShell, create a custom policy that uses the CloudShellPolicy managed policy as a template. Alternatively, edit an inline policy that's embedded in the relevant IAM identity (user, group, or role).

For example, you can allow IAM users to access CloudShell, but prevent them from forwarding the CloudShell environment credentials that are used to log in to AWS Management Console.

Important

To launch AWS CloudShell from the AWS Management Console, an IAM user needs permissions for the following actions:

  • CreateEnvironment

  • CreateSession

  • GetEnvironmentStatus

  • StartEnvironment

If one of these actions isn't explicitly allowed by an attached policy, an IAM permissions error is returned when you try to launch CloudShell.

AWS CloudShell permissions
Name Description of permission granted Required to launch CloudShell?

cloudshell:CreateEnvironment

Creates a CloudShell environment, retrieves the layout at the start of the CloudShell session, and saves the current layout from the web application in the backend. This permission only expects * as the value for Resource as outlined in Examples of IAM policies for CloudShell.

Yes

cloudshell:CreateSession

Connects to a CloudShell environment from the AWS Management Console.

Yes

cloudshell:GetEnvironmentStatus

Read the status of a CloudShell environment.

Yes

cloudshell:DeleteEnvironment

Deletes a CloudShell environment.

No

cloudshell:GetFileDownloadUrls

Generates pre-signed Amazon S3 URLs that are used to download files through CloudShell using the CloudShell web interface. This is not available for VPC environments.

No

cloudshell:GetFileUploadUrls

Generates pre-signed Amazon S3 URLs that are used to upload files through CloudShell using the CloudShell web interface. This is not available for VPC environments.

No

cloudshell:DescribeEnvironments Describes the environments. No

cloudshell:PutCredentials

Forwards the credentials used to log in to the AWS Management Console to CloudShell.

No

cloudshell:StartEnvironment

Starts a CloudShell environment that is stopped.

Yes

cloudshell:StopEnvironment

Stops a CloudShell environment that is running.

No

Examples of IAM policies for CloudShell

The following examples show how policies can be created to restrict who can access CloudShell. The examples also show the actions that can be performed in the shell environment.

This following policy enforces a complete denial of access to CloudShell and its features.

{ "Version": "2012-10-17", "Statement": [{ "Sid": "DenyCloudShell", "Effect": "Deny", "Action": [ "cloudshell:*" ], "Resource": "*" }] }

This following policy allows IAM users to access CloudShell but blocks them from generating pre-signed URLs for file upload and download. Users can still transfer files to and from the environment, using clients like wget for example.

{ "Version": "2012-10-17", "Statement": [ { "Sid": "AllowUsingCloudshell", "Effect": "Allow", "Action": [ "cloudshell:*" ], "Resource": "*" }, { "Sid": "DenyUploadDownload", "Effect": "Deny", "Action": [ "cloudshell:GetFileDownloadUrls", "cloudshell:GetFileUploadUrls" ], "Resource": "*" }] }

The following policy allows IAM users to access CloudShell. However, the policy prevents the credentials that you used to log in to AWS Management Console from being forwarded to the CloudShell environment. IAM users with this policy need to manually configure their credentials within CloudShell.

{ "Version": "2012-10-17", "Statement": [ { "Sid": "AllowUsingCloudshell", "Effect": "Allow", "Action": [ "cloudshell:*" ], "Resource": "*" }, { "Sid": "DenyCredentialForwarding", "Effect": "Deny", "Action": [ "cloudshell:PutCredentials" ], "Resource": "*" }] }

The following policy allows IAM users to create AWS CloudShell environments.

{ "Version": "2012-10-17", "Statement": [{ "Sid": "CloudShellUser", "Effect": "Allow", "Action": [ "cloudshell:CreateEnvironment", "cloudshell:CreateSession", "cloudshell:GetEnvironmentStatus", "cloudshell:StartEnvironment" ], "Resource": "*" }] }

Required IAM permissions for creating and using CloudShell VPC environments

To create and use CloudShell VPC environments, the IAM administrator must enable access to VPC specific Amazon EC2 permissions. This section lists the Amazon EC2 permissions needed to create and use VPC environments.

To create VPC environments, the IAM policy assigned to your role must include the following Amazon EC2 permissions:

  • ec2:DescribeVpcs

  • ec2:DescribeSubnets

  • ec2:DescribeSecurityGroups

  • ec2:DescribeDhcpOptions

  • ec2:DescribeNetworkInterfaces

  • ec2:CreateTags

  • ec2:CreateNetworkInterface

  • ec2:CreateNetworkInterfacePermission

We recommend also including:

  • ec2:DeleteNetworkInterface

Note

This permission is not mandatory, but this is required for CloudShell to clean up the ENI resource (ENIs created for CloudShell VPC environments are tagged with ManagedByCloudShell key) created by it. If this permission not in enabled, you must manually clean up the ENI resource after every CloudShell VPC environment use.

IAM policy granting full CloudShell access including access to VPC

The following example displays how to enable full permissions, including access to VPC, to CloudShell:

{ "Version": "2012-10-17", "Statement": [ { "Sid": "AllowCloudShellOperations", "Effect": "Allow", "Action": [ "cloudshell:*" ], "Resource": "*" }, { "Sid": "AllowDescribeVPC", "Effect": "Allow", "Action": [ "ec2:DescribeDhcpOptions", "ec2:DescribeNetworkInterfaces", "ec2:DescribeSubnets", "ec2:DescribeSecurityGroups", "ec2:DescribeVpcs" ], "Resource": "*" }, { "Sid": "AllowCreateTagWithCloudShellKey", "Effect": "Allow", "Action": [ "ec2:CreateTags" ], "Resource": "arn:aws:ec2:*:*:network-interface/*", "Condition": { "StringEquals": { "ec2:CreateAction": "CreateNetworkInterface" }, "ForAnyValue:StringEquals": { "aws:TagKeys": "ManagedByCloudShell" } } }, { "Sid": "AllowCreateNetworkInterfaceWithSubnetsAndSG", "Effect": "Allow", "Action": [ "ec2:CreateNetworkInterface" ], "Resource": [ "arn:aws:ec2:*:*:subnet/*", "arn:aws:ec2:*:*:security-group/*" ] }, { "Sid": "AllowCreateNetworkInterfaceWithCloudShellTag", "Effect": "Allow", "Action": [ "ec2:CreateNetworkInterface" ], "Resource": "arn:aws:ec2:*:*:network-interface/*", "Condition": { "ForAnyValue:StringEquals": { "aws:TagKeys": "ManagedByCloudShell" } } }, { "Sid": "AllowCreateNetworkInterfacePermissionWithCloudShellTag", "Effect": "Allow", "Action": [ "ec2:CreateNetworkInterfacePermission" ], "Resource": "arn:aws:ec2:*:*:network-interface/*", "Condition": { "StringEquals": { "aws:ResourceTag/ManagedByCloudShell": "" } } }, { "Sid": "AllowDeleteNetworkInterfaceWithCloudShellTag", "Effect": "Allow", "Action": [ "ec2:DeleteNetworkInterface" ], "Resource": "arn:aws:ec2:*:*:network-interface/*", "Condition": { "StringEquals": { "aws:ResourceTag/ManagedByCloudShell": "" } } } ] }

Using IAM condition keys for VPC environments

You can use CloudShell-specific condition keys for VPC settings to provide additional permission controls for your VPC environments. You can also specify the subnets and security groups that the VPC environment can and can't use.

CloudShell supports the following condition keys in IAM policies:

  • CloudShell:VpcIds – Allow or deny one or more VPCs

  • CloudShell:SubnetIds – Allow or deny one or more subnets

  • CloudShell:SecurityGroupIds – Allow or deny one or more security groups

Note

If the permissions for users with access to public CloudShell environments are modified to add restriction to the cloudshell:createEnvironment action, they can still access their existing public environment. However, if you want to modify an IAM policy with this restriction and disable their access to the existing public environment, you must first update the IAM policy with the restriction, and then ensure that every CloudShell user in your account manually deletes the existing public environment using the CloudShell web user interface (ActionsDelete CloudShell environment).

Example policies with condition keys for VPC settings

The following examples demonstrate how to use condition keys for VPC settings. After you create a policy statement with the desired restrictions, append the policy statement for the target user or role.

Ensure that users create only VPC environments and deny creation of public environments

To ensure that users can create only VPC environments, use the deny permission as shown in the following example:

{ "Statement": [ { "Sid": "DenyCloudShellNonVpcEnvironments", "Action": [ "cloudshell:CreateEnvironment" ], "Effect": "Deny", "Resource": "*", "Condition": { "Null": { "cloudshell:VpcIds": "true" } } } ] }

Deny users access to specific VPCs, subnets, or security groups

To deny users access to specific VPCs, use StringEquals to check the value of the cloudshell:VpcIds condition. The following example denies users access to vpc-1 and vpc-2:

{ "Version": "2012-10-17", "Statement": [ { "Sid": "EnforceOutOfVpc", "Action": [ "cloudshell:CreateEnvironment" ], "Effect": "Deny", "Resource": "*", "Condition": { "StringEquals": { "cloudshell:VpcIds": [ "vpc-1", "vpc-2" ] } } } ] }

To deny users access to specific VPCs, use StringEquals to check the value of the cloudshell:SubnetIds condition. The following example denies users access to subnet-1 and subnet-2:

{ "Version": "2012-10-17", "Statement": [ { "Sid": "EnforceOutOfVpc", "Action": [ "cloudshell:CreateEnvironment" ], "Effect": "Deny", "Resource": "*", "Condition": { "StringEquals": { "cloudshell:VpcIds": [ "vpc-1", "vpc-2" ] } } } ] }

To deny users access to specific VPCs, use StringEquals to check the value of the cloudshell:SecurityGroupIds condition. The following example denies users access to sg-1 and sg-2:

{ "Version": "2012-10-17", "Statement": [ { "Sid": "EnforceOutOfSecurityGroups", "Action": [ "cloudshell:CreateEnvironment" ], "Effect": "Deny", "Resource": "*", "Condition": { "ForAnyValue:StringEquals": { "cloudshell:SecurityGroupIds": [ "sg-1", "sg-2" ] } } } ] }

Allow users to create environments with specific VPC configurations

To allow users access to specific VPCs, use StringEquals to check the value of the cloudshell:VpcIds condition. The following example allows users access to vpc-1 and vpc-2:

{ "Version": "2012-10-17", "Statement": [ { "Sid": "EnforceStayInSpecificVpc", "Action": [ "cloudshell:CreateEnvironment" ], "Effect": "Allow", "Resource": "*", "Condition": { "StringEquals": { "cloudshell:VpcIds": [ "vpc-1", "vpc-2" ] } } } ] }

To allow users access to specific VPCs, use StringEquals to check the value of the cloudshell:SubnetIds condition. The following example allows users access to subnet-1 and subnet-2:

{ "Version": "2012-10-17", "Statement": [ { "Sid": "EnforceStayInSpecificSubnets", "Action": [ "cloudshell:CreateEnvironment" ], "Effect": "Allow", "Resource": "*", "Condition": { "ForAllValues:StringEquals": { "cloudshell:SubnetIds": [ "subnet-1", "subnet-2" ] } } } ] }

To allow users access to specific VPCs, use StringEquals to check the value of the cloudshell:SecurityGroupIds condition. The following example allows users access to sg-1 and sg-2:

{ "Version": "2012-10-17", "Statement": [ { "Sid": "EnforceStayInSpecificSecurityGroup", "Action": [ "cloudshell:CreateEnvironment" ], "Effect": "Allow", "Resource": "*", "Condition": { "ForAllValues:StringEquals": { "cloudshell:SecurityGroupIds": [ "sg-1", "sg-2" ] } } } ] }

Permissions for accessing AWS services

CloudShell uses the IAM credentials that you used to sign in to the AWS Management Console.

Note

To use the IAM credentials that you used to sign in to the AWS Management Console, you must have cloudshell:PutCredentials permission.

This pre-authentication feature of CloudShell makes it convenient to use AWS CLI. However, an IAM user still requires explicit permissions for the AWS services that are called from the command line.

For example, suppose that IAM users are required to create Amazon S3 buckets and upload files as objects to them. You can create a policy that explicitly allows those actions. The IAM console provides an interactive visual editor that guides through the process of building up a JSON-formatted policy document. After the policy is created, you can attach it to relevant IAM identity (user, group, or role).

For more information about attaching managed policies, see Adding IAM identity permissions (console) in the IAM User Guide.