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Configure AWS Credentials for GitHub Actions

Configure your AWS credentials and region environment variables for use in other GitHub Actions. This action implements the AWS SDK credential resolution chain and exports environment variables for your other Actions to use. Environment variable exports are detected by both the AWS SDKs and the AWS CLI for AWS API calls.

Recent updates

GitHub OIDC Changes

In #357, we observed that GitHub recently started offering one of several intermediate OIDC endpoint thumbprints. Because IAM requires statically configured endpoint thumbprints, AWS customers that had only one thumbprint configured could see intermittent authentication failures. As of July 6, 2023, AWS has made a change to IAM that will no longer require any particular certificate thumbprint for tokens.actions.githubusercontent.com, which is the GitHub OIDC endpoint. Instead, AWS secures communication with GitHub OIDC using our library of trusted CAs rather than using a certificate thumbprint to verify the server certificate. The IAM APIs still require that a thumbprint is configured, but those thumbprints will be ignored when authenticating tokens.actions.githubusercontent.com.

GitHub Enterprise Server customers use a different endpoint so they are not affected by this change.

Original message: There are now two possible intermediary certificates for the Actions SSL certificate. Previously, the certificate with the thumbprint 6938fd4d98bab03faadb97b34396831e3780aea1 was guaranteed to return. Now, the certificate with the thumbprint 1c58a3a8518e8759bf075b76b750d4f2df264fcd can also be returned, so you will need to update your identity provider with this additional new thumbprint.

Usage
Credentials
Assuming a Role
- Session tagging
- Sample IAM Role Permissions
Self-Hosted Runners
- Proxy Configuration
License Summary
Security Disclosures

Usage

We support four methods for fetching credentials from AWS, but we recommend that you use GitHub's OIDC provider in conjunction with a configured AWS IAM Identity Provider endpoint.

To do that, you would add the following step to your workflow:

    - name: Configure AWS Credentials
      uses: aws-actions/configure-aws-credentials@v2
      with:
        role-to-assume: arn:aws:iam::123456789100:role/my-github-actions-role
        aws-region: us-east-2

This will cause the action to perform an AssumeRoleWithWebIdentity call and return temporary security credentials for use by other actions. In order for this to work, you'll need to preconfigure the IAM IdP in your AWS account (see Assuming a Role for details).

You can use this action with the AWS CLI available in GitHub's hosted virtual environments or run this action multiple times to use different AWS accounts, regions, or IAM roles in the same GitHub Actions workflow. As an example, here is a complete workflow file that uploads artifacts to Amazon S3.

jobs:
  deploy:
    name: Upload to Amazon S3
    runs-on: ubuntu-latest
    # These permissions are needed to interact with GitHub's OIDC Token endpoint.
    permissions:
      id-token: write
      contents: read
    steps:
    - name: Checkout
      uses: actions/checkout@v3
    - name: Configure AWS credentials from Test account
      uses: aws-actions/configure-aws-credentials@v2
      with:
        role-to-assume: arn:aws:iam::111111111111:role/my-github-actions-role-test
        aws-region: us-east-1
    - name: Copy files to the test website with the AWS CLI
      run: |
        aws s3 sync . s3://my-s3-test-website-bucket
    - name: Configure AWS credentials from Production account
      uses: aws-actions/configure-aws-credentials@v2
      with:
        role-to-assume: arn:aws:iam::222222222222:role/my-github-actions-role-prod
        aws-region: us-west-2
    - name: Copy files to the production website with the AWS CLI
      run: |
        aws s3 sync . s3://my-s3-prod-website-bucket

See action.yml for the full documentation for this action's inputs and outputs.

Credentials

We recommend following Amazon IAM best practices for the AWS credentials used in GitHub Actions workflows, including:

Do not store credentials in your repository's code.
Grant least privilege to the credentials used in GitHub Actions workflows. Grant only the permissions required to perform the actions in your GitHub Actions workflows.
Monitor the activity of the credentials used in GitHub Actions workflows.

Assuming a Role

There are four different supported ways to retrieve credentials. We recommend using GitHub's OIDC provider to get short-lived credentials needed for your actions. Specifying role-to-assume without providing an aws-access-key-id or a web-identity-token-file, or setting role-chaining, will signal to the action that you wish to use the OIDC provider. If role-chaining is true, existing credentials in the environment will be used to assume role-to-assume.

The following table describes which identity is used based on which values are supplied to the Action:

Identity Used	`aws-access-key-id`	`role-to-assume`	`web-identity-token-file`	`role-chaining`
[✅ Recommended] Assume Role directly using GitHub OIDC provider		✔
IAM User	✔
Assume Role using IAM User credentials	✔	✔
Assume Role using WebIdentity Token File credentials		✔	✔
Assume Role using existing credentials		✔		✔

Credential Lifetime

The default session duration is 1 hour when using the OIDC provider to directly assume an IAM Role or when an aws-session-token is directly provided. The default session duration is 6 hours when using an IAM User to assume an IAM Role (by providing an aws-access-key-id, aws-secret-access-key, and a role-to-assume) .

If you would like to adjust this you can pass a duration to role-duration-seconds, but the duration cannot exceed the maximum that was defined when the IAM Role was created. The default session name is GitHubActions, and you can modify it by specifying the desired name in role-session-name. The default audience is sts.amazonaws.com which you can replace by specifying the desired audience name in audience.

Examples

AssumeRoleWithWebIdentity (recommended)

    - name: Configure AWS Credentials
      uses: aws-actions/configure-aws-credentials@v2
      with:
        aws-region: us-east-2
        role-to-assume: arn:aws:iam::123456789100:role/my-github-actions-role
        role-session-name: MySessionName

In this example, the Action will load the OIDC token from the GitHub-provided environment variable and use it to assume the role arn:aws:iam::123456789100:role/my-github-actions-role with the session name MySessionName.

AssumeRole with static IAM credentials in repository secrets

    - name: Configure AWS Credentials
      uses: aws-actions/configure-aws-credentials@v2
      with:
        aws-region: us-east-2
        role-to-assume: arn:aws:iam::123456789100:role/my-github-actions-role
        role-session-name: MySessionName
    - name: Configure other AWS Credentials
      uses: aws-actions/configure-aws-credentials@v2
      with:
        aws-region: us-east-2
        role-to-assume: arn:aws:iam::987654321000:role/my-second-role
        role-session-name: MySessionName
        role-chaining: true

In this two-step example, the first step will use OIDC to assume the role arn:aws:iam::123456789100:role/my-github-actions-role just as in the prior example. Following that, a second step will use this role to assume a different role, arn:aws:iam::987654321000:role/my-second-role.

    - name: Configure AWS Credentials
      uses: aws-actions/configure-aws-credentials@v2
      with:
        aws-access-key-id: ${{ secrets.AWS_ACCESS_KEY_ID }}
        aws-secret-access-key: ${{ secrets.AWS_SECRET_ACCESS_KEY }}
        aws-region: us-east-2
        role-to-assume: ${{ secrets.AWS_ROLE_TO_ASSUME }}
        role-external-id: ${{ secrets.AWS_ROLE_EXTERNAL_ID }}
        role-duration-seconds: 1200
        role-session-name: MySessionName

In this example, the secret AWS_ROLE_TO_ASSUME contains a string like arn:aws:iam::123456789100:role/my-github-actions-role. To assume a role in the same account as the static credentials, you can simply specify the role name, like role-to-assume: my-github-actions-role.

AssumeRoleWithWebIdentity using a custom audience

    - name: Configure AWS Credentials for Beta Customers
      uses: aws-actions/configure-aws-credentials@v2
      with:
        audience: beta-customers
        aws-region: us-east-3
        role-to-assume: arn:aws:iam::123456789100:role/my-github-actions-role
        role-session-name: MySessionName

In this example, the audience has been changed from the default to use a different audience name beta-customers. This can help ensure that the role can only affect those AWS accounts whose GitHub OIDC providers have explicitly opted in to the beta-customers label.

Changing the default audience may be necessary when using non-default AWS partitions.

AssumeRoleWithWebIdentity and disable secure Action outputs

    - name: Configure AWS Credentials
      uses: aws-actions/configure-aws-credentials@v2
      with:
        aws-region: us-east-2
        role-to-assume: arn:aws:iam::123456789100:role/my-github-actions-role
        role-session-name: MySessionName
        mask-aws-account-id: false

In this example, account ID masking has been disabled. By default, the AWS account ID will be obscured in the action's output. This may be helpful when debugging action failures.

Sample IAM OIDC CloudFormation Template

If you choose to use GitHub's OIDC provider, you must first set up federation with the provider in as an IAM IdP. The GitHub OIDC provider only needs to be created once per account (i.e. multiple IAM Roles that can be assumed by the GitHub's OIDC can share a single OIDC Provider).

Note that the thumbprint has been set to all F's because the thumbprint is not used when authenticating tokens.actions.githubusercontent.com. Instead, IAM uses its library of trusted CAs to authenticate. However, this value is still required by the API.

This CloudFormation template will configure the IdP for you. You can copy the template below, or load it from here: https://d38mtn6aq9zhn6.cloudfront.net/configure-aws-credentials-latest.yml

Parameters:
  GitHubOrg:
    Description: Name of GitHub organization/user (case sensitive)
    Type: String
  RepositoryName:
    Description: Name of GitHub repository (case sensitive)
    Type: String
  OIDCProviderArn:
    Description: Arn for the GitHub OIDC Provider.
    Default: ""
    Type: String
  OIDCAudience:
    Description: Audience supplied to configure-aws-credentials.
    Default: "sts.amazonaws.com"
    Type: String

Conditions:
  CreateOIDCProvider: !Equals 
    - !Ref OIDCProviderArn
    - ""

Resources:
  Role:
    Type: AWS::IAM::Role
    Properties:
      AssumeRolePolicyDocument:
        Statement:
          - Effect: Allow
            Action: sts:AssumeRoleWithWebIdentity
            Principal:
              Federated: !If 
                - CreateOIDCProvider
                - !Ref GithubOidc
                - !Ref OIDCProviderArn
            Condition:
              StringEquals:
                token.actions.githubusercontent.com:aud: !Ref OIDCAudience
              StringLike:
                token.actions.githubusercontent.com:sub: !Sub repo:${GitHubOrg}/${RepositoryName}:*

  GithubOidc:
    Type: AWS::IAM::OIDCProvider
    Condition: CreateOIDCProvider
    Properties:
      Url: https://token.actions.githubusercontent.com
      ClientIdList: 
        - sts.amazonaws.com
      ThumbprintList:
        - ffffffffffffffffffffffffffffffffffffffff

Outputs:
  Role:
    Value: !GetAtt Role.Arn

To align with the Amazon IAM best practice of granting least privilege, the assume role policy document should contain a Condition that specifies a subject allowed to assume the role. Without a subject condition, any GitHub user or repository could potentially assume the role. The subject can be scoped to a GitHub organization and repository as shown in the CloudFormation template. Additional claim conditions can be added for higher specificity as explained in the GitHub documentation. Due to implementation details, not every OIDC claim is presently supported by IAM.

For further information on OIDC and GitHub Actions, please see:

Session tagging

The session will have the name "GitHubActions" and be tagged with the following tags: (GITHUB_ environment variable definitions can be found here)

Key	Value
GitHub	"Actions"
Repository	GITHUB_REPOSITORY
Workflow	GITHUB_WORKFLOW
Action	GITHUB_ACTION
Actor	GITHUB_ACTOR
Branch	GITHUB_REF
Commit	GITHUB_SHA

Note: all tag values must conform to the requirements. Particularly, GITHUB_WORKFLOW will be truncated if it's too long. If GITHUB_ACTOR or GITHUB_WORKFLOW contain invalid characters, the characters will be replaced with an '*'.

The action will use session tagging by default during role assumption. Note that for WebIdentity role assumption, the session tags have to be included in the encoded WebIdentity token. This means that Tags can only be supplied by the OIDC provider and not set during the AssumeRoleWithWebIdentity API call within the Action. You can skip this session tagging by providing role-skip-session-tagging as true in the action's inputs:

      uses: aws-actions/configure-aws-credentials@v2
      with:
        role-skip-session-tagging: true

Inline session policy

An IAM policy in stringified JSON format that you want to use as an inline session policy. Depending on preferences, the JSON could be written on a single line like this:

      uses: aws-actions/configure-aws-credentials@v2
      with:
         inline-session-policy: '{"Version":"2012-10-17","Statement":[{"Sid":"Stmt1","Effect":"Allow","Action":"s3:List*","Resource":"*"}]}'

Or we can have a nicely formatted JSON as well:

      uses: aws-actions/configure-aws-credentials@v2
      with:
         inline-session-policy: >-
          {
           "Version": "2012-10-17",
           "Statement": [
            {
             "Sid":"Stmt1",
             "Effect":"Allow",
             "Action":"s3:List*",
             "Resource":"*"
            }
           ]
          }

Managed session policies

The Amazon Resource Names (ARNs) of the IAM managed policies that you want to use as managed session policies. The policies must exist in the same account as the role. You can pass a single managed policy like this:

      uses: aws-actions/configure-aws-credentials@v2
      with:
         managed-session-policies: arn:aws:iam::aws:policy/AmazonS3ReadOnlyAccess

And we can pass multiple managed policies likes this:

      uses: aws-actions/configure-aws-credentials@v2
      with:
         managed-session-policies: |
          arn:aws:iam::aws:policy/AmazonS3ReadOnlyAccess
          arn:aws:iam::aws:policy/AmazonS3OutpostsReadOnlyAccess

Self-Hosted Runners

If you run your GitHub Actions in a self-hosted runner that already has access to AWS credentials, such as an EC2 instance, then you do not need to provide IAM user access key credentials to this action. We will use the standard AWS JavaScript SDK credential resolution methods to find your credentials, so if the AWS JS SDK can authenticate on your runner, this Action will as well.

If no access key credentials are given in the action inputs, this action will use credentials from the runner environment using the default methods for the AWS SDK for Javascript.

You can use this action to simply configure the region and account ID in the environment, and then use the runner's credentials for all AWS API calls made by your Actions workflow:

uses: aws-actions/configure-aws-credentials@v2
with:
  aws-region: us-east-2

In this case, your runner's credentials must have permissions to call any AWS APIs called by your Actions workflow.

Or, you can use this action to assume a role, and then use the role credentials for all AWS API calls made by your Actions workflow:

uses: aws-actions/configure-aws-credentials@v2
with:
  aws-region: us-east-2
  role-to-assume: my-github-actions-role

In this case, your runner's credentials must have permissions to assume the role.

You can also assume a role using a web identity token file, such as if using Amazon EKS IRSA. Pods running in EKS worker nodes that do not run as root can use this file to assume a role with a web identity.

Proxy Configuration

If you run in self-hosted environments and in secured environment where you need use a specific proxy you can set it in the action manually.

Additionally this action will always consider already configured proxy in the environment.

Manually configured proxy:

uses: aws-actions/configure-aws-credentials@v2
with:
  aws-region: us-east-2
  role-to-assume: my-github-actions-role
  http-proxy: "http://companydomain.com:3128"

Proxy configured in the environment variable:

# Your environment configuration
HTTP_PROXY="http://companydomain.com:3128"

The action will read the underlying proxy configuration from the environment and you don't need to configure it in the action.

Use with the AWS CLI

This workflow does not install the AWS CLI into your environment. Self-hosted runners that intend to run this action prior to executing aws commands need to have the AWS CLI installed if it's not already present. Most GitHub hosted runner environments should include the AWS CLI by default.

License Summary

This code is made available under the MIT license.

Security Disclosures

If you would like to report a potential security issue in this project, please do not create a GitHub issue. Instead, please follow the instructions here or email AWS security directly.

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