diff --git a/README.md b/README.md index 1a96120..07c33de 100644 --- a/README.md +++ b/README.md @@ -1,98 +1,130 @@ -## Configure AWS Credentials for GitHub Actions -Configure your AWS credentials and region environment variables for use in other -GitHub Actions. +Configure AWS Credentials +========================= +Autenticate to AWS in GitHub Actions! Works especially well with [AWS Secrets +Manager](https://github.com/aws-actions/aws-secretsmanager-get-secrets). -This action implements the AWS JavaScript SDK credential resolution chain -and exports session 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. +Quick Start (OIDC, recommended) +------------------------------- +1. Create an IAM Identity Provider in your AWS account for GitHub OIDC. (See +[OIDC configuration](#oidc-configuration) below for details.) +2. Create an IAM Role in your AWS account with a trust policy that allows GitHub +Actions to assume it: +
+ GitHub OIDC Trust Policy -## Overview -API calls to AWS need to be signed with credential information, so when you use -one of the AWS SDKs or an AWS tool, you must provide it with AWS credentials and -and AWS region. One way to do that in GitHub Actions is to use a repository -secret with IAM credentials, but this doesn't follow [AWS security -guidelines](https://docs.aws.amazon.com/IAM/latest/UserGuide/security-creds.html) -on using long term credentials. Instead, we recommend that you use a long term -credential or JWT to fetch a temporary credential, and use that with your tools -instead. This GitHub Action facilitates just that. + ```json + { + "Version": "2012-10-17", + "Statement": [ + { + "Effect": "Allow", + "Principal": { + "Federated": "arn:aws:iam:::oidc-provider/token.actions.githubusercontent.com" + }, + "Action": "sts:AssumeRoleWithWebIdentity", + "Condition": { + "StringEquals": { + "token.actions.githubusercontent.com:aud": "sts.amazonaws.com", + "token.actions.githubusercontent.com:sub": "repo:/:ref:refs/heads/" + } + } + } + ] + } + ``` +
+3. Attach permissions to the IAM Role that allow it to access the AWS resources +you need. +4. Add the following to your GitHub Actions workflow: +
+ Example Workflow -AWS SDKs and Tools look for your credentials in standardized environment -variables. In essence, this Action runs through the standard [credential -resolution flow](https://docs.aws.amazon.com/sdkref/latest/guide/standardized-credentials.html), -and at the end, exports environment variables for you to use later. + ```yaml + # Need ID token write permission to use OIDC + permissions: + id-token: write + jobs: + run_job_with_aws: + runs-on: ubuntu-latest + steps: + - name: Configure AWS Credentials + uses: aws-actions/configure-aws-credentials@main # Or a specific version + with: + role-to-assume: + aws-region: + - name: Additional steps + run: | + # Your commands that require AWS credentials + aws sts get-caller-identity + ``` +
+That's it! Your GitHub Actions workflow can now access AWS resources using the +IAM Role you created. Other authentication scenarios are also supported (see +below). -We support five 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. +Security Recommendations +------------------------ +* Use temporary credentials when possible. OIDC is recommended because it + provides temporary credentials and it's easy to set up. +* Do not store credentials in your repository's code. Consider using + [git-secrets](https://github.com/awslabs/git-secrets) to prevent committing + secrets to your repository. +* [Grant least privilege](https://docs.aws.amazon.com/IAM/latest/UserGuide/best-practices.html#grant-least-privilege) + to your workflows. Grant only those permissions that are necessary for the + workflow to run. +* [Monitor the activity](https://docs.aws.amazon.com/IAM/latest/UserGuide/best-practices.html#keep-a-log) + of the credentials used in workflows. +* Periodically rotate any long-lived credentials that you use. +* Store sensitive information in a secure way, such as using + [AWS Secrets Manager](https://aws.amazon.com/secrets-manager/) or + [GitHub Secrets](https://docs.github.com/en/actions/security-guides/encrypted-secrets). -For more information on how to do that, read on. +Other Authentication Scenarios +------------------------------ +This action supports five different authentication methods that are configured +by specifying different inputs. -### Note about GHES - -Some of this documentation may be inaccurate if you are using GHES (GitHub -Enterprise Server), please take note to review the GitHub documentation when -relevant. - -For example, the URL that the OIDC JWT is issued from is different than the -usual `token.actions.githubusercontent.com`, and will be unique to your -enterprise server. As a result, you will need to configure this differently when -you create the Identity Provider. - -We do not presently have a GHES testing environment to validate this action. If -you are running in GHES and encounter problems, please -[let us know](https://github.com/aws-actions/configure-aws-credentials/issues/new/choose). - -## Security recommendations - -We recommend following -[Amazon IAM best practices](https://docs.aws.amazon.com/IAM/latest/UserGuide/best-practices.html) -for the AWS credentials used in GitHub Actions workflows, including: - * Do not store credentials in your repository's code. - * [Grant least privilege](https://docs.aws.amazon.com/IAM/latest/UserGuide/best-practices.html#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. - Do not assume overly permissive roles, even for testing. - * [Monitor the activity](https://docs.aws.amazon.com/IAM/latest/UserGuide/best-practices.html#keep-a-log) - of the credentials used in GitHub Actions workflows. - * Use temporary credentials when possible. - * Periodically rotate any long-term credentials you use. - -## Using this action -There are five different supported ways to retrieve credentials: - -- Using GitHub's OIDC provider (`AssumeRoleWithWebIdentity`) -- Proceeding as an IAM user (No STS call is made) -- Using access keys as action input (`AssumeRole`) -- Using a WebIdentity Token File (`AssumeRoleWithWebIdentity`) -- Using existing credentials in your runner (`AssumeRole`) +1. Use a `core.getIDToken()` call to authenticate via OIDC. +2. Re-export existing long-lived IAM credentials (access key ID and secret + access key) as environment variables. +3. Use static credentials stored in GitHub Secrets to fetch temporary + credentials via STS AssumeRole. +4. Use a Web Identity Token to fetch temporary credentials via STS + AssumeRoleWithWebIdentity. +5. Use credentials stored in the Action environment to fetch temporary + credentials via STS AssumeRole. Because we use the AWS JavaScript SDK, we always will use the [credential resolution flow for Node.js](https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/setting-credentials-node.html). Depending on your inputs, the action might override parts of this flow. -We recommend using the first option above: [GitHub's OIDC provider](https://docs.github.com/en/actions/deployment/security-hardening-your-deployments/configuring-openid-connect-in-amazon-web-services). -This method uses OIDC to get short-lived credentials needed for your actions. -See [OIDC](#OIDC) for more information on how to setup your AWS account to -assume a role with OIDC. +
+Inputs and their effects on the credential resolution flow -The following table describes which method we'll use to get your credentials -based on which values are supplied to the Action: - -| **Identity Used** | `aws-access-key-id` | `role-to-assume` | `web-identity-token-file` | `role-chaining` | `id-token` permission -| --------------------------------------------------------------- | ------------------- | ---------------- | ------------------------- | - | - | -| [✅ 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 | | ✔ | | ✔ | | +| **Identity Used** | `aws-access-key-id` | `role-to-assume` | `web-identity-token-file` | `role-chaining` | +| ---------------------------------------- | ------------------- | ---------------- | ------------------------- | --------------- | +| [✅ Recommended] GitHub OIDC | | ✔ | | | +| IAM User (no AssumeRole) | ✔ | | | | +| AssumeRole using static IAM credentials | ✔ | ✔ | | | +| AssumeWithWebIdentity use a token file | | ✔ | ✔ | | +| AssumeRole using existing credentials | | ✔ | | ✔ | *Note: `role-chaining` is not always necessary to use existing credentials. If you're getting a "Credentials loaded by the SDK do not match" error, try enabling this option.* +
+Additionally, **`aws-region`** is always required. + +*Note: If you use GitHub Enterprise Server, you must use the you may need to +adjust examples here to match your environment.* + +Additional Options +------------------ ### Options See [action.yml](./action.yml) for more detail. +
+Options list and descriptions | Option | Description | Required | |---------------------------|---------------------------------------------------------------------------------------------------|----------| @@ -119,25 +151,67 @@ See [action.yml](./action.yml) for more detail. | retry-max-attempts | Limits the number of retry attempts before giving up. Defaults to 12. | No | | special-characters-workaround | Uncommonly, some environments cannot tolerate special characters in a secret key. This option will retry fetching credentials until the secret access key does not contain special characters. This option overrides disable-retry and retry-max-attempts. | No | | use-existing-credentials | When set, the action will check if existing credentials are valid and exit if they are. Defaults to false. | No | +
-#### Credential Lifetime -The default session duration is **1 hour**. +#### Adjust the retry mechanism +You can configure retry settings for if the STS call fails. By default, we +retry with exponential backoff `12` times. You can disable this behavior +altogether by setting the `disable-retry` input to `true`, or you can configure +the number of times it retries with the `retry-max-attempts` input. -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. +#### Mask account ID +Your account ID is not masked by default in workflow logs. You can set the +`mask-aws-account-id` input to `true` to mask your account ID in workflow logs +if desired. -#### External ID -If your role requires an external ID to assume, you can provide the external ID -with the `role-external-id` input +#### Unset current credentials +Sometimes, existing credentials in your runner can get in the way of the +intended outcome. You can set the `unset-current-credentials` input to `true` to +work around this issue. -#### Session tagging and name +#### Use an HTTP proxy + +If need use an HTTP proxy you can set it in the action manually. Additionally +this action will always consider the `HTTP_PROXY` environment variable. + +
+Proxy configuration + +Manually configured proxy: +```yaml +uses: aws-actions/configure-aws-credentials@v4.1.0 +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: +```bash +# Your environment configuration +HTTP_PROXY="http://companydomain.com:3128" +``` +
+ +#### Special characters in AWS_SECRET_ACCESS_KEY +Some edge cases are unable to properly parse an `AWS_SECRET_ACCESS_KEY` if it +contains special characters. For more information, please see the +[AWS CLI documentation](https://docs.aws.amazon.com/cli/latest/userguide/cli-chap-troubleshooting.html#tshoot-signature-does-not-match). +If you set the `special-characters-workaround` option, this action will +continually retry fetching credentials until we get one that does not have +special characters. This option overrides the `disable-retry` and +`retry-max-attempts` options. We recommend that you do not enable this option +unless required, because retrying APIs infinitely until they succeed is not best +practice. + +Session Naming and Policies +--------------------------- The default session name is "GitHubActions", and you can modify it by specifying the desired name in `role-session-name`. -_Note: you might find it helpful to set the `role-session-name` to `${{ github.run_id }}` +*Note: you might find it helpful to set the `role-session-name` to `${{ github.run_id }}` so as to clarify in audit logs which AWS actions were performed by which workflow -run._ +run.* The session will be tagged with the following tags: (Refer to [GitHub's documentation for `GITHUB_` environment @@ -159,21 +233,7 @@ 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, unless -you follow our recommendation and are assuming a role with a WebIdentity. 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 they cannot set during the AssumeRoleWithWebIdentity API call -within the Action. See [#419](https://github.com/aws-actions/configure-aws-credentials/issues/419) -for more information. - -You can skip this session tagging by providing -`role-skip-session-tagging` as true in the action's inputs: -```yaml - uses: aws-actions/configure-aws-credentials@v4 - with: - role-skip-session-tagging: true -``` +The action will use session tagging by default unless you are using OIDC. To forward session tags to subsequent sessions in a role chain, you can use the `transitive-tag-keys` input to specify the keys of the tags to be passed. Eg. @@ -196,7 +256,11 @@ session policy by its ARN. #### Inline session policies 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: +line. + +
+Inline session policy examples + ```yaml uses: aws-actions/configure-aws-credentials@v4 with: @@ -219,11 +283,16 @@ Or we can have a nicely formatted JSON as well: ] } ``` +
#### 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: +the role. + +
+Managed session policy examples + ```yaml uses: aws-actions/configure-aws-credentials@v4.1.0 with: @@ -237,38 +306,10 @@ And we can pass multiple managed policies likes this: arn:aws:iam::aws:policy/AmazonS3ReadOnlyAccess arn:aws:iam::aws:policy/AmazonS3OutpostsReadOnlyAccess ``` +
-### Misc - -#### Adjust the retry mechanism -You can now configure retry settings for when the STS call fails. By default, we -retry with exponential backoff `12` times. You can disable this behavior -altogether by setting the `disable-retry` input to `true`, or you can configure -the number of times it retries with the `retry-max-attempts` input. - -#### Mask account ID -Your account ID is not masked by default in workflow logs since it's not -considered sensitive information. However, you can set the `mask-aws-account-id` -input to `true` to mask your account ID in workflow logs if desired. - -#### Unset current credentials -Sometimes, existing credentials in your runner can get in the way of the -intended outcome. You can set the `unset-current-credentials` input to `true` to -work around this issue. - -#### Special characters in AWS_SECRET_ACCESS_KEY -Some edge cases are unable to properly parse an `AWS_SECRET_ACCESS_KEY` if it -contains special characters. For more information, please see the -[AWS CLI documentation](https://docs.aws.amazon.com/cli/latest/userguide/cli-chap-troubleshooting.html#tshoot-signature-does-not-match). -If you set the `special-characters-workaround` option, this action will -continually retry fetching credentials until we get one that does not have -special characters. This option overrides the `disable-retry` and -`retry-max-attempts` options. We recommend that you do not enable this option -unless required, because retrying APIs infinitely until they succeed is not best -practice. - -## OIDC - +OIDC Configuration +------------------- We recommend using [GitHub's OIDC provider](https://docs.github.com/en/actions/deployment/security-hardening-your-deployments/configuring-openid-connect-in-amazon-web-services) to get short-lived AWS credentials needed for your actions. When using OIDC, you @@ -287,15 +328,6 @@ To get this to work 5. Specify that role's ARN when setting up this action. -First, in order for this action to create the JWT, your workflow file must have -the `id-token: write` permission: - -```yaml - permissions: - id-token: write - contents: read -``` - ### OIDC Audience When the JWT is created, an audience needs to be specified. Normally, you would @@ -314,75 +346,25 @@ You can specify the audience through the `audience` input: ``` ### Configuring IAM to trust GitHub -To use GitHub's OIDC provider, you must first set up federation -with the provider 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). Here is a sample CloudFormation -template that will configure this trust for you. +To use GitHub's OIDC provider, you must first set up federation in your AWS +account. This involves creating an IAM Identity Provider that trusts GitHub's +OIDC endpoint. You can create an IAM Identity Provider in the AWS Management +Console by specifying the following details: +- **Provider Type**: OIDC +- **Provider URL**: `https://token.actions.githubusercontent.com` +- **Audience**: `sts.amazonaws.com` (or your custom audience if you specified + one in the `audience` input) -Note that the thumbprint below has been set to all F's because the thumbprint is -not used when authenticating `token.actions.githubusercontent.com`. This is a -special case used *only when GitHub's OIDC is authenticating to IAM*. IAM uses -its library of trusted CAs to authenticate. The value is still the API, so it -must be specified. +Prior versions of this documentation gave instructions for specifying the +certificate fingerprint, but this is no longer necessary. The thumbprint, if +specified, will be ignored. -You can copy the template below, or load it from here: -https://d38mtn6aq9zhn6.cloudfront.net/configure-aws-credentials-latest.yml +You can also create the IAM Identity Provider using the AWS CLI: -```yaml -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 +```bash +aws iam create-open-id-connect-provider \ + --url https://token.actions.githubusercontent.com \ + --client-id-list sts.amazonaws.com ``` ### Claims and scoping permissions @@ -424,80 +406,10 @@ For further information on OIDC and GitHub Actions, please see: * [GitHub docs: Configuring OpenID Connect in Amazon Web Services](https://docs.github.com/en/actions/deployment/security-hardening-your-deployments/configuring-openid-connect-in-amazon-web-services) * [GitHub changelog: GitHub Actions: Secure cloud deployments with OpenID Connect](https://github.blog/changelog/2021-10-27-github-actions-secure-cloud-deployments-with-openid-connect/) -## Self-Hosted Runners +Examples +-------- -If you run your GitHub Actions in a -[self-hosted runner](https://help.github.com/en/actions/hosting-your-own-runners/about-self-hosted-runners) 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](https://docs.aws.amazon.com/sdk-for-javascript/v3/developer-guide/setting-credentials-node.html). - -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: -```yaml -uses: aws-actions/configure-aws-credentials@v4.1.0 -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: -```yaml -uses: aws-actions/configure-aws-credentials@v4.1.0 -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](https://docs.aws.amazon.com/eks/latest/userguide/iam-roles-for-service-accounts-technical-overview.html). 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 need use a HTTP proxy you can set it in the action manually. - -Additionally this action will always consider the `HTTP_PROXY` environment -variable. - -Manually configured proxy: -```yaml -uses: aws-actions/configure-aws-credentials@v4.1.0 -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: -```bash -# Your environment configuration -HTTP_PROXY="http://companydomain.com:3128" -``` - -### Use with the AWS CLI -This workflow does _not_ install the [AWS CLI](https://aws.amazon.com/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](https://docs.aws.amazon.com/cli/latest/userguide/cli-chap-install.html) -if it's not already present. -Most [GitHub hosted runner environments](https://github.com/actions/virtual-environments) -should include the AWS CLI by default. - -## Examples - -### AssumeRoleWithWebIdentity (recommended) +### AssumeRoleWithWebIdentity ```yaml - name: Configure AWS Credentials uses: aws-actions/configure-aws-credentials@v4.1.0 @@ -578,12 +490,14 @@ This example shows that you can reference the fetched credentials as outputs if `output-credentials` is set to true. This example also shows that you can use the `aws-session-token` input in a situation where session tokens are fetched and passed to this action. - -## License Summary + +License +------- This code is made available under the MIT license. -## Security Disclosures +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](https://aws.amazon.com/security/vulnerability-reporting/) or [email AWS -security directly](mailto:aws-security@amazon.com). +do not create a GitHub issue. Instead, please follow the instructions +[here](https://aws.amazon.com/security/vulnerability-reporting/) or +[email AWS security](mailto:aws-security@amazon.com) directly.