Configure Workload Identity Federation with AWS or Azure

This guide describes how to use Workload Identity Federation to let AWS and Azure workloads authenticate to Google Cloud without a service account key.

Using Workload Identity Federation, workloads that run on AWS EC2 and Azure can exchange their environment-specific credentials for short-lived Google Cloud Security Token Service tokens.

Environment-specific credentials include the following:

By setting up Workload Identity Federation, you can let these workloads exchange these environment-specific credentials against short-lived Google Cloud credentials. Workloads can use these short-lived credentials to access Google Cloud APIs.

Before you begin

  • Set up authentication.

    Select the tab for how you plan to use the samples on this page:

    Console

    When you use the Google Cloud console to access Google Cloud services and APIs, you don't need to set up authentication.

    gcloud

    In the Google Cloud console, activate Cloud Shell.

    Activate Cloud Shell

    At the bottom of the Google Cloud console, a Cloud Shell session starts and displays a command-line prompt. Cloud Shell is a shell environment with the Google Cloud CLI already installed and with values already set for your current project. It can take a few seconds for the session to initialize.

    Python

    To use the Python samples on this page in a local development environment, install and initialize the gcloud CLI, and then set up Application Default Credentials with your user credentials.

    1. Install the Google Cloud CLI.

    2. If you're using an external identity provider (IdP), you must first sign in to the gcloud CLI with your federated identity.

    3. If you're using a local shell, then create local authentication credentials for your user account: 

      gcloud auth application-default login

      You don't need to do this if you're using Cloud Shell.

      If an authentication error is returned, and you are using an external identity provider (IdP), confirm that you have signed in to the gcloud CLI with your federated identity.

    For more information, see Set up ADC for a local development environment in the Google Cloud authentication documentation.

Prepare your external identity provider

You only need to perform these steps once for each Microsoft Entra ID tenant or AWS account.

AWS

You don't need to make any configuration changes in your AWS account.

After you configure a workload identity pool to trust your AWS account, you can let AWS users and AWS roles use permanent or temporary AWS security credentials to obtain short-lived Google Cloud credentials.

Azure

You must create a new Microsoft Entra ID application in your Microsoft Entra ID tenant and configure it so that it can be used for Workload Identity Federation.

After you configure a workload identity pool to trust the application, Azure users and service principals can request access tokens for this application and exchange these access tokens against short-lived Google Cloud credentials.

To create the application, do the following:

  1. Create a Microsoft Entra ID application and service principal.

  2. Set an Application ID URI for the application. You can use the default Application ID URI (APPID) or specify a custom URI.

    You need the Application ID URI later when you configure the workload identity pool provider.

To let an application obtain access tokens for the Microsoft Entra ID application, you can use managed identities:

  1. Create a managed identity. Note the Object ID of the managed identity. You need it later when you configure impersonation.

  2. Assign the managed identity to a virtual machine or another resource that runs your application.

Configure Workload Identity Federation

You only need to perform these steps once per AWS account or Microsoft Entra ID tenant. You can then use the same workload identity pool and provider for multiple workloads and across multiple Google Cloud projects.

To start configuring Workload Identity Federation, do the following:

  1. In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

    Go to project selector

    2. It's best to use a dedicated project to manage workload identity pools and providers.

  2. Make sure that billing is enabled for your Google Cloud project.

    3. Enable the IAM, Resource Manager, Service Account Credentials, and Security Token Service APIs.

    Enable the APIs

Define an attribute mapping and condition

The environment-specific credentials of your AWS or Azure workload contain multiple attributes, and you must decide which attribute you want to use as subject identifier (google.subject) in Google Cloud.

Google Cloud uses the subject identifier in Cloud Audit Logs and in principal identifiers to uniquely identify an AWS or Azure user or role.

Optionally, you can map additional attributes. You can then refer to these additional attributes when granting access to resources.

AWS

Your attribute mapping can use the response fields for GetCallerIdentity as source attributes. These fields include the following:

  • account: the AWS account number.
  • arn: the AWS ARN of the external entity.
  • userid: the unique identifier of the calling entity.

If your application runs on an Amazon Elastic Compute Cloud (EC2) instance with an attached role, you can use the following attribute mapping:

google.subject=assertion.arn
attribute.account=assertion.account
attribute.aws_role=assertion.arn.extract('assumed-role/{role}/')
attribute.aws_ec2_instance=assertion.arn.extract('assumed-role/{role_and_session}').extract('/{session}')

The mapping does the following:

  • Uses the ARN as subject identifier—for example: "arn:aws:sts::000000000000:assumed-role/ec2-my-role/i-00000000000000000
  • Introduces a custom attribute account and assigns it the AWS account ID
  • Introduces a custom attribute aws_role and assigns it the AWS role name—for example: ec2-my-role
  • Introduces a custom attribute aws_ec2_instance and assigns it the EC2 instance ID—for example: i-00000000000000000

Using this mapping, you can grant access to:

  • A specific EC2 instance: 

    principalSet://iam.googleapis.com/projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/attribute.aws_ec2_instance/EC2_INSTANCE_ID

  • All users and instances in a role: 

    principalSet://iam.googleapis.com/projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/attribute.aws_role/ROLE_NAME

Azure

Your attribute mappings can use the claims embedded in Azure access tokens, including custom claims, as source attributes. In most cases, it's best to use the sub claim as subject identifier:

google.subject=assertion.sub
When the `sub` claim surpasses the 127-character limit for google.subject, employing an [`extract` function](/iam/docs/conditions-attribute-reference#extract) to derive meaningful claims for use as the subject identifier is recommended: 
google.subject=assertion.sub.extract('/eid1/c/pub/t/{sub_claim}')

For an access token issued to a managed identity, the sub claim contains the Object ID of the managed identity. If you use a different claim, make sure that the claim is unique and can't be reassigned.

If you're unsure about the list of claims you can reference, do the following:

  1. Connect to an Azure VM that has an assigned managed identity.

  2. Obtain an access token from the Azure Instance Metadata Service (IMDS):

    Bash

    curl \
  "http://169.254.169.254/metadata/identity/oauth2/token?resource=APP_ID_URI&api-version=2018-02-01" \
  -H "Metadata: true" | jq -r .access_token

    This command uses the jq tool. jq is available by default in Cloud Shell.

    PowerShell

    $SubjectTokenType = "urn:ietf:params:oauth:token-type:jwt"
$SubjectToken = (Invoke-RestMethod `
  -Uri "http://169.254.169.254/metadata/identity/oauth2/token?resource=APP_ID_URI&api-version=2018-02-01" `
  -Headers @{Metadata="true"}).access_token
Write-Host $SubjectToken

    Replace APP_ID_URI with the Application ID URI of the application that you've configured for Workload Identity Federation.

  3. In a web browser, go to https://jwt.ms/ and paste the access token into the field.

  4. Click Claims to view the list of claims embedded in the access token.

For service identities, it's typically not necessary to create a mapping for google.groups or any custom attributes.

Optionally, define an attribute condition. Attribute conditions are CEL expressions that can check assertion attributes and target attributes. If the attribute condition evaluates to true for a given credential, the credential is accepted. Otherwise, the credential is rejected.

AWS

You can use an attribute condition to restrict which IAM users and roles can use Workload Identity Federation to obtain short-lived Google Cloud tokens.

For example, the following condition restricts access to AWS roles and disallows other IAM identifiers:

assertion.arn.startsWith('arn:aws:sts::AWS_ACCOUNT_ID:assumed-role/')

Azure

You can use an attribute condition to restrict which users and service principals can use Workload Identity Federation to obtain short-lived Google Cloud tokens. Alternatively, you can configure your Microsoft Entra ID application to use app role assignments.

Create the workload identity pool and provider

Required roles

To get the permissions that you need to configure Workload Identity Federation, ask your administrator to grant you the following IAM roles on the project:

For more information about granting roles, see Manage access to projects, folders, and organizations.

You might also be able to get the required permissions through custom roles or other predefined roles.

Alternatively, the IAM Owner (roles/owner) basic role also includes permissions to configure identity federation. You should not grant basic roles in a production environment, but you can grant them in a development or test environment.

You now have collected all of the information that you need to create a workload identity pool and provider:

Console

  1. In the Google Cloud console, go to the New workload provider and pool page.

    Go to New workload provider and pool

  2. In the Create an identity pool section, enter the following:

    • Name: Name for the pool. The name is also used as the pool ID. You can't change the pool ID later.
    • Description: Text that describes the purpose of the pool.

  3. Click Continue.

  4. Configure provider settings:

    AWS

    Configure the following provider settings:

    • Select a provider: AWS.
    • Provider name: the name for the provider. The name is also used as the provider ID. You cannot change the provider ID later.

    Azure

    Configure the following provider settings:

    • Select a provider: OpenID Connect (OIDC).
    • Provider name: Name for the provider. The name is also used as the provider ID. You cannot change the provider ID later.
    • Issuer URL: https://sts.windows.net/TENANT_ID. Replace TENANT_ID with the tenant ID (GUID) of your Microsoft Entra ID tenant.
    • Allowed audiences: Application ID URI that you used when you registered the application in Microsoft Entra ID.

  5. Click Continue.

  6. In the Configure provider attributes section, add the attribute mappings that you've identified previously.

  7. In the Attribute conditions section, enter the attribute condition that you identified previously. Leave the field blank if you don't have an attribute condition.

  8. Click Save to create the workload identity pool and provider.

gcloud

  1. Create a new workload identity pool:

    gcloud iam workload-identity-pools create POOL_ID \
    --location="global" \
    --description="DESCRIPTION" \
    --display-name="DISPLAY_NAME"

    Replace the following:

    • POOL_ID: the unique ID for the pool.
    • DISPLAY_NAME: the name of the pool.
    • DESCRIPTION: the description of the pool. This description appears when granting access to pool identities.

  2. Add a workload identity pool provider:

    AWS

    To create the workload identity pool provider for AWS, execute the following command:

    gcloud iam workload-identity-pools providers create-aws PROVIDER_ID \
  --location="global" \
  --workload-identity-pool="POOL_ID" \
  --account-id="ACCOUNT_ID" \
  --attribute-mapping="MAPPINGS" \
  --attribute-condition="CONDITIONS"

    Replace the following:

    Example:

    gcloud iam workload-identity-pools providers create-aws example-provider \
  --location="global" \
  --workload-identity-pool="pool-1" \
  --account-id="123456789000" \
  --attribute-mapping="google.subject=assertion.arn"

    Azure

    To create the workload identity pool provider for Azure, execute the following command:

    gcloud iam workload-identity-pools providers create-oidc PROVIDER_ID \
    --location="global" \
    --workload-identity-pool="POOL_ID" \
    --issuer-uri="ISSUER_URI" \
    --allowed-audiences="APPLICATION_ID_URI" \
    --attribute-mapping="MAPPINGS" \
    --attribute-condition="CONDITIONS"

    Replace the following:

    • PROVIDER_ID: The unique ID for the provider.
    • POOL_ID: The ID of the pool.
    • ISSUER_URI: The tenant ID (GUID) of your Microsoft Entra ID tenant, sometimes formatted as https://sts.windows.net/TENANT_ID. The issuer URI can vary, and to find your issuer URI, you can debug your JWT using JWT.io.
    • APPLICATION_ID_URI: Application ID URI that you used when you registered the application in Microsoft Entra ID.
    • MAPPINGS: The comma-separated list of attribute mappings that you previously identified.
    • CONDITIONS: (Optional) The attribute condition that you previously identified.

    Example:

    gcloud iam workload-identity-pools providers create-oidc example-provider \
    --location="global" \
    --workload-identity-pool="pool-1" \
    --issuer-uri="https://sts.windows.net/00000000-1111-2222-3333-444444444444" \
    --allowed-audiences="api://my-app" \
    --attribute-mapping="google.subject=assertion.sub,google.groups=assertion.groups"

Authenticate a workload

You must perform these steps once per workload.

Allow your external workload to access Google Cloud resources

To provide your workload with access to Google Cloud resources, we recommend that you grant direct resource access to the principal. In this case, the principal is the federated user. Some Google Cloud products have Google Cloud API limitations. If your workload calls an API endpoint that has a limitation, you can instead use service account impersonation. In this case, the principal is the Google Cloud service account, which acts as the identity. You grant access to the service account on the resource.

Direct resource access

You can grant access to a federated identity directly on resources by using the Google Cloud console or the gcloud CLI.

Console

To use the Google Cloud console to grant IAM roles directly on a resource, you must go to the resource's page, and then grant the role. The following example shows you how to go to the Cloud Storage page and grant the role Storage Object Viewer (roles/storage.objectViewer) to a federated identity directly on a Cloud Storage bucket.

  1. In the Google Cloud console, go to the Cloud Storage Buckets page.

    Go to Buckets

  2. In the list of buckets, click the name of the bucket for which you want to grant the role.

  3. Select the Permissions tab near the top of the page.

  4. Click the Grant access button.

    The Add principals dialog appears.

  5. In the New principals field, enter one or more identities that need access to your bucket.

    By subject 

    principal://iam.googleapis.com/projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/subject/SUBJECT

    Replace the following:

    • PROJECT_NUMBER: the project number
    • POOL_ID: the workload pool ID
    • SUBJECT: the individual subject mapped from your IdP—for example, administrator@example.com

    By group 

    principalSet://iam.googleapis.com/projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/group/GROUP

    Replace the following:

    • PROJECT_NUMBER: the project number
    • WORKLOAD_POOL_ID: the workload pool ID
    • GROUP: the group mapped from your IdP—for example: administrator-group@example.com

    By attribute 

    principalSet://iam.googleapis.com/projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/attribute.ATTRIBUTE_NAME/ATTRIBUTE_VALUE

    Replace the following:

    • PROJECT_NUMBER: the project number
    • WORKLOAD_POOL_ID: the workload pool ID
    • ATTRIBUTE_NAME: one of the attributes that was mapped from your IdP
    • ATTRIBUTE_VALUE: the value of the attribute

  6. Select a role (or roles) from the Select a role drop-down menu. The roles you select appear in the pane with a short description of the permissions they grant.

  7. Click Save.

gcloud

To use the gcloud CLI to grant IAM roles on a resource in a project, do the following:

  1. Obtain the project number of the project in which the resource is defined.

    gcloud projects describe $(gcloud config get-value core/project) --format=value\(projectNumber\)

  2. Grant access to the resource.

    To use the gcloud CLI to grant the role Storage Object Viewer (roles/storage.objectViewer) to external identities that meet certain criteria, run the following command.

    By subject

    gcloud storage buckets add-iam-policy-binding BUCKET_ID \
    --role=roles/storage.objectViewer \
    --member="principal://iam.googleapis.com/projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/subject/SUBJECT"

    By group

    gcloud storage buckets add-iam-policy-binding BUCKET_ID \
    --role=roles/storage.objectViewer \
    --member="principalSet://iam.googleapis.com/projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/group/GROUP"

    By attribute

    gcloud storage buckets add-iam-policy-binding BUCKET_ID \
    --role=roles/storage.objectViewer \
    --member="principalSet://iam.googleapis.com/projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/attribute.ATTRIBUTE_NAME/ATTRIBUTE_VALUE"

    Replace the following:

    • BUCKET_ID: the bucket on which to grant access
    • PROJECT_NUMBER: the project number. of the project that contains the workload identity pool
    • POOL_ID: the pool ID of the workload identity pool
    • SUBJECT: the expected value for the attribute that you've mapped to google.subject
    • GROUP: the expected value for the attribute that you've mapped to google.groups
    • ATTRIBUTE_NAME: the name of a custom attribute in your attribute mapping
    • ATTRIBUTE_VALUE: the value of the custom attribute in your attribute mapping

    You can grant roles on any Google Cloud resource that supports IAM allow policies.

Service account impersonation

  1. To create a service account for the external workload, do the following:

    1. Enable the IAM, Security Token Service, and Service Account Credentials APIs.

      Enable the APIs

    2. Create a service account that represents the workload. We recommend that you use a dedicated service account for each workload. The service account doesn't need to be in the same project as the workload identity pool, but you must refer to the project that contains the service account.

    3. Grant the service account access to resources that you want external identities to access.

  2. To let the federated identity impersonate the service account, do the following:

Console

To use the Google Cloud console to grant IAM roles to a federated identity with service account, do the following:

Service Account in the same project

  1. To grant access using service account impersonation for a service account in the same project, do the following:

    1. Go to the Workload Identity Pools page.

      Go to Workload Identity Pools

    2. Select Grant access.

    3. In the Grant access to service account dialog, select Grant access using Service Account impersonation.

    4. In the Service accounts list, select the service account for the external identities to impersonate, and do the following:

    5. To choose which identities in the pool can impersonate the service account, perform one of the following actions:

      • To allow only specific identities of the workload identity pool to impersonate the service account, select Only identities matching the filter.

      • In the Attribute name list, select the attribute that you want to filter on.

      • In the Attribute value field, enter the expected value of the attribute; for example, if you use an attribute mapping google.subject=assertion.sub, set Attribute name to subject and Attribute value to the value of the sub claim in tokens that are issued by your external identity provider.

    6. To save the configuration, click Save and then Dismiss.

Service account in a different project

  1. To grant access using service account impersonation for a service account in a different project, do the following:

    1. Go to the Service Accounts page.

      Go to Service Accounts

    2. Select the service account that you want to impersonate.

    3. Click Manage access.

    4. Click Add principal.

    5. In the New principal field, enter one of the following principal identifiers for the identities in your pool that will impersonate the service account.

      By subject 

      principal://iam.googleapis.com/projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/subject/SUBJECT

      Replace the following:

      • PROJECT_NUMBER: the project number
      • POOL_ID: the workload pool ID
      • SUBJECT: the individual subject mapped from your IdP—for example, administrator@example.com

      By group 

      principalSet://iam.googleapis.com/projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/group/GROUP

      Replace the following:

      • PROJECT_NUMBER: the project number
      • WORKLOAD_POOL_ID: the workload pool ID
      • GROUP: the group mapped from your IdP—for example: administrator-group@example.com

      By attribute 

      principalSet://iam.googleapis.com/projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/attribute.ATTRIBUTE_NAME/ATTRIBUTE_VALUE

      Replace the following:

      • PROJECT_NUMBER: the project number
      • WORKLOAD_POOL_ID: the workload pool ID
      • ATTRIBUTE_NAME: one of the attributes that was mapped from your IdP
      • ATTRIBUTE_VALUE: the value of the attribute

      By pool

      principalSet://iam.googleapis.com/projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/*

      Replace the following:

      • PROJECT_NUMBER: the project number
      • WORKLOAD_POOL_ID: the workload pool ID

    6. In Select a role, select the Workload Identity User role (roles/iam.workloadIdentityUser).

    7. To save the configuration, click Save.

gcloud

To grant the Workload Identity User role (roles/iam.workloadIdentityUser) to a federated principal or principal set, run the following command. To learn more about Workload Identity Federation principal identifiers, see Principal types.

By subject

gcloud iam service-accounts add-iam-policy-binding SERVICE_ACCOUNT_EMAIL \
    --role=roles/iam.workloadIdentityUser \
    --member="principal://iam.googleapis.com/projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/subject/SUBJECT"

By group

gcloud iam service-accounts add-iam-policy-binding SERVICE_ACCOUNT_EMAIL \
    --role=roles/iam.workloadIdentityUser \
    --member="principalSet://iam.googleapis.com/projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/group/GROUP"

By attribute

gcloud iam service-accounts add-iam-policy-binding SERVICE_ACCOUNT_EMAIL \
    --role=roles/iam.workloadIdentityUser \
    --member="principalSet://iam.googleapis.com/projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/attribute.ATTRIBUTE_NAME/ATTRIBUTE_VALUE"

Replace the following:

  • SERVICE_ACCOUNT_EMAIL: the email address of the service account
  • PROJECT_NUMBER: the project number. of the project that contains the workload identity pool
  • POOL_ID: the pool ID of the workload identity pool
  • SUBJECT: the expected value for the attribute that you've mapped to google.subject
  • GROUP: the expected value for the attribute that you've mapped to google.groups
  • ATTRIBUTE_NAME: the name of a custom attribute in your attribute mapping
  • ATTRIBUTE_VALUE: the value of the custom attribute in your attribute mapping

Download or create a credential configuration

The Cloud Client Libraries, the gcloud CLI, and Terraform, can automatically obtain external credentials, and use these credentials to impersonate a service account. To let libraries and tools complete this process, you have to provide a credential configuration file. This file defines the following:

  • Where to obtain external credentials from
  • Which workload identity pool and provider to use
  • Which service account to impersonate

To create a credential configuration file, do the following:

Console

To download a credential configuration file in the Google Cloud console, do the following:

  1. In the Google Cloud console, go to the Workload Identity Pools page.

    Go to Workload Identity Pools

  2. Find the workload identity pool for the IdP that you want to use and click it.

  3. If you chose to use direct resource access, do the following:

    1. Click Grant access.

    2. Select Grant access using federated identities (Recommended).

    3. Click Download.

    4. Continue with instructions to Configure your application dialog, later in this procedure.

  4. If you chose to use service account impersonation, do the following:

    1. Select Connected service accounts.

    2. Find the service account you want to use and click Download.

    3. Continue with instructions to Configure your application dialog, later in this procedure.

  5. In the Configure your application dialog, select the provider that contains the external identities.

  6. Provide the following additional settings:

    AWS

    No additional settings required.

    Azure

    Application ID URL: Application ID URI of the Azure application

  7. Select Download config to download the credential configuration file, then click Dismiss.

gcloud

To create a credential configuration file by using gcloud iam workload-identity-pools create-cred-config, do the following:

AWS

To create a credential configuration file that lets the library obtain an access token from EC2 instance metadata, do the following:

gcloud iam workload-identity-pools create-cred-config \
    projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/providers/PROVIDER_ID \
    --service-account=SERVICE_ACCOUNT_EMAIL \
    --service-account-token-lifetime-seconds=SERVICE_ACCOUNT_TOKEN_LIFETIME \
    --aws \
    --output-file=FILEPATH.json

Replace the following:

  • PROJECT_NUMBER: The project number of the project that contains the workload identity pool
  • POOL_ID: The ID of the workload identity pool.
  • PROVIDER_ID: The ID of the workload identity pool provider.
  • SERVICE_ACCOUNT_EMAIL: If you use service account impersonation, replace with the email address of the service account. Omit this flag if you don't use service account impersonation.
  • SERVICE_ACCOUNT_TOKEN_LIFETIME: If you use service account impersonation, replace with the lifetime of the service account access token, in seconds; this defaults to one hour when not provided. Omit this flag if you don't use service account impersonation. To specify a lifetime longer than one hour, you must configure the constraints/iam.allowServiceAccountCredentialLifetimeExtension organizational policy constraint.
  • FILEPATH: The file to save configuration to.

If you use AWS IMDSv2, an additional flag --enable-imdsv2 needs to be added to the gcloud iam workload-identity-pools create-cred-config command:

gcloud iam workload-identity-pools create-cred-config \
    projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/providers/PROVIDER_ID \
    --service-account=SERVICE_ACCOUNT_EMAIL \
    --aws \
    --enable-imdsv2 \
    --output-file=FILEPATH.json

If using the AWS metadata server isn't an option, you can provide AWS security credentials through the following AWS environment variables:

  • AWS_ACCESS_KEY_ID
  • AWS_SECRET_ACCESS_KEY
  • Either of AWS_REGION or AWS_DEFAULT_REGION
  • Optional: AWS_SESSION_TOKEN

The gcloud CLI and libraries use these AWS environment variables when the AWS metadata server is unavailable.

Azure

Create a credential configuration file that lets the library obtain an access token from the Azure Instance Metadata Service (IMDS):

gcloud iam workload-identity-pools create-cred-config \
    projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/providers/PROVIDER_ID \
    --service-account=SERVICE_ACCOUNT_EMAIL \
    --service-account-token-lifetime-seconds=SERVICE_ACCOUNT_TOKEN_LIFETIME \
    --azure \
    --app-id-uri APPLICATION_ID_URI \
    --output-file=FILEPATH.json

Replace the following:

  • PROJECT_NUMBER: The project number of the project that contains the workload identity pool.
  • POOL_ID: The ID of the workload identity pool.
  • PROVIDER_ID: The ID of the workload identity pool provider.
  • SERVICE_ACCOUNT_EMAIL: If you use service account impersonation, replace with the email address of the service account. Omit this flag if you don't use service account impersonation.
  • APPLICATION_ID_URI: The Application ID URI of the Azure application.
  • SERVICE_ACCOUNT_TOKEN_LIFETIME: If you use service account impersonation,lifetime of the service account access token, in seconds; this defaults to one hour when not provided. Omit this flag if you don't use service account impersonation. To specify a lifetime longer than one hour, you must configure the constraints/iam.allowServiceAccountCredentialLifetimeExtension organizational policy constraint.
  • FILEPATH: The file to save configuration to.

Use the credential configuration to access Google Cloud

To let tools and client libraries use your credential configuration, do the following in your AWS or Azure environment:

  1. Initialize an environment variable GOOGLE_APPLICATION_CREDENTIALS and point it to the credential configuration file:

    Bash

      export GOOGLE_APPLICATION_CREDENTIALS=`pwd`/FILEPATH.json
    where FILEPATH is the relative path to the credential configuration file.

    PowerShell

      $env:GOOGLE_APPLICATION_CREDENTIALS = Resolve-Path 'FILEPATH.json'
    where FILEPATH is the relative path to the credential configuration file.

  2. Use a client library or tool that supports Workload Identity Federation and can find credentials automatically:

    C++

    The Google Cloud Client Libraries for C++ support Workload Identity Federation since version v2.6.0. To use Workload Identity Federation, you must build the client libraries with version 1.36.0 or later of gRPC.

    Go

    Client libraries for Go support Workload Identity Federation if they use version v0.0.0-20210218202405-ba52d332ba99 or later of the golang.org/x/oauth2 module.

    To check which version of this module your client library uses, run the following commands:

    cd $GOPATH/src/cloud.google.com/go
go list -m golang.org/x/oauth2

    Java

    Client libraries for Java support Workload Identity Federation if they use version 0.24.0 or later of the com.google.auth:google-auth-library-oauth2-http artifact.

    To check which version of this artifact your client library uses, run the following Maven command in your application directory:

    mvn dependency:list -DincludeArtifactIds=google-auth-library-oauth2-http

    Node.js

    Client libraries for Node.js support Workload Identity Federation if they use version 7.0.2 or later of the google-auth-library package.

    To check which version of this package your client library uses, run the following command in your application directory:

    npm list google-auth-library

    When you create a GoogleAuth object, you can specify a project ID, or you can allow GoogleAuth to find the project ID automatically. To find the project ID automatically, the service account in the configuration file must have the Browser role (roles/browser), or a role with equivalent permissions, on your project. For details, see the README for the google-auth-library package.

    Python

    Client libraries for Python support Workload Identity Federation if they use version 1.27.0 or later of the google-auth package.

    To check which version of this package your client library uses, run the following command in the environment where the package is installed:

    pip show google-auth

    To specify a project ID for the authentication client, you can set the GOOGLE_CLOUD_PROJECT environment variable, or you can allow the client to find the project ID automatically. To find the project ID automatically, the service account in the configuration file must have the Browser role (roles/browser), or a role with equivalent permissions, on your project. For details, see the user guide for the google-auth package.

    gcloud

    To authenticate using Workload Identity Federation, use the gcloud auth login command:

    gcloud auth login --cred-file=FILEPATH.json

    Replace FILEPATH with the path to the credential configuration file.

    Support for Workload Identity Federation in gcloud CLI is available in version 363.0.0 and later versions of the gcloud CLI.

    Terraform

    The Google Cloud provider supports Workload Identity Federation if you use version 3.61.0 or later:

    terraform {
  required_providers {
    google = {
      source  = "hashicorp/google"
      version = "~> 3.61.0"
    }
  }
}

    bq

    To authenticate using Workload Identity Federation, use the gcloud auth login command, as follows:

    gcloud auth login --cred-file=FILEPATH.json

    Replace FILEPATH with the path to the credential configuration file.

    Support for Workload Identity Federation in bq is available in version 390.0.0 and later versions of the gcloud CLI.

    If you can't use a client library that supports Workload Identity Federation, you can authenticate programmatically by using the REST API.

Advanced scenarios

Authenticate a workload using the REST API

If you can't use the client libraries, you can follow these steps to let an external workload obtain a short-lived access token by using the REST API:

  1. Obtain credentials from your external IdP:

    AWS

    Create a JSON document that contains the information that you would normally include in a request to the AWS GetCallerIdentity() endpoint, including a valid request signature.

    Workload Identity Federation refers to this JSON document as a GetCallerIdentity token. The token lets Workload Identity Federation verify the identity without revealing the AWS secret access key.

    A GetCallerIdentity token looks similar to the following:

    {
  "url": "https://sts.amazonaws.com?Action=GetCallerIdentity&Version=2011-06-15",
  "method": "POST",
  "headers": [
    {
      "key": "Authorization",
      "value" : "AWS4-HMAC-SHA256 Credential=AKIASOZTBDV4D7ABCDEDF/20200228/us-east-1/sts/aws4_request, SignedHeaders=host;x-amz-date,Signature=abcedefdfedfd"
    },
    {
      "key": "host",
      "value": "sts.amazonaws.com"
    },
    {
      "key": "x-amz-date",
      "value": "20200228T225005Z"
    },
    {
      "key": "x-goog-cloud-target-resource",
      "value": "//iam.googleapis.com/projects/12345678/locations/global/workloadIdentityPools/my-pool/providers/my-aws-provider"
    },
    {
      "key": "x-amz-security-token",
      "value": "GizFWJTqYX...xJ55YoJ8E9HNU="
    }
  ]
}

    The token contains the following fields:

    • url: The URL of the AWS STS endpoint for GetCallerIdentity(), with the body of a standard GetCallerIdentity() request appended as query parameters. For example, https://sts.amazonaws.com?Action=GetCallerIdentity&Version=2011-06-15. We recommend that you use regional STS endpoints and design a reliable infrastructure for your workloads. For more information, see Regional AWS STS endpoints.
    • method: The HTTP request method: POST.
    • headers: The HTTP request headers, which must include:
      • Authorization: The request signature.
      • host: The hostname of the url field; for example, sts.amazonaws.com.
      • x-amz-date: The time you will send the request, formatted as an ISO 8601 Basic string. This value is typically set to the current time and is used to help prevent replay attacks.
      • x-goog-cloud-target-resource: The full resource name of the identity provider without a https: prefix. For example: 
        //iam.googleapis.com/projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/providers/PROVIDER_ID
      • x-amz-security-token: Session token. Only required if you are using temporary security credentials.

    The following example creates a URL-encoded GetCallerIdentity token. Extract the URL-encoded token for later use. It also creates a human-readable token just for your reference:

    import json
import urllib

import boto3
from botocore.auth import SigV4Auth
from botocore.awsrequest import AWSRequest


def create_token_aws(project_number: str, pool_id: str, provider_id: str) -> None:
    # Prepare a GetCallerIdentity request.
    request = AWSRequest(
        method="POST",
        url="https://sts.amazonaws.com/?Action=GetCallerIdentity&Version=2011-06-15",
        headers={
            "Host": "sts.amazonaws.com",
            "x-goog-cloud-target-resource": f"//iam.googleapis.com/projects/{project_number}/locations/global/workloadIdentityPools/{pool_id}/providers/{provider_id}",
        },
    )

    # Set the session credentials and Sign the request.
    # get_credentials loads the required credentials as environment variables.
    # Refer:
    # https://boto3.amazonaws.com/v1/documentation/api/latest/guide/credentials.html
    SigV4Auth(boto3.Session().get_credentials(), "sts", "us-east-1").add_auth(request)

    # Create token from signed request.
    token = {"url": request.url, "method": request.method, "headers": []}
    for key, value in request.headers.items():
        token["headers"].append({"key": key, "value": value})

    # The token lets workload identity federation verify the identity without revealing the AWS secret access key.
    print("Token:\n%s" % json.dumps(token, indent=2, sort_keys=True))
    print("URL encoded token:\n%s" % urllib.parse.quote(json.dumps(token)))


def main() -> None:
    # TODO(Developer): Replace the below credentials.
    # project_number: Google Project number (not the project id)
    project_number = "my-project-number"
    pool_id = "my-pool-id"
    provider_id = "my-provider-id"

    create_token_aws(project_number, pool_id, provider_id)


if __name__ == "__main__":
    main()

    Initialize the following variables:

    Bash

    SUBJECT_TOKEN_TYPE="urn:ietf:params:aws:token-type:aws4_request"
SUBJECT_TOKEN=TOKEN

    PowerShell

    $SubjectTokenType = "urn:ietf:params:aws:token-type:aws4_request"
$SubjectToken = "TOKEN"

    Where TOKEN is the URL encoded GetCallerIdentity token that was generated by the script.

    Azure

    Connect to an Azure VM that has an assigned managed identity and obtain an access token from the Azure Instance Metadata Service (IMDS):

    Bash

    SUBJECT_TOKEN_TYPE="urn:ietf:params:oauth:token-type:jwt"
SUBJECT_TOKEN=$(curl \
  "http://169.254.169.254/metadata/identity/oauth2/token?resource=APP_ID_URI&api-version=2018-02-01" \
  -H "Metadata: true" | jq -r .access_token)
echo $SUBJECT_TOKEN

    This command uses the jq tool. jq is available by default in Cloud Shell.

    PowerShell

    $SubjectTokenType = "urn:ietf:params:oauth:token-type:jwt"
$SubjectToken = (Invoke-RestMethod `
  -Uri "http://169.254.169.254/metadata/identity/oauth2/token?resource=APP_ID_URI&api-version=2018-02-01" `
  -Headers @{Metadata="true"}).access_token
Write-Host $SubjectToken

    Where APP_ID_URI is the Application ID URI of the application that you've configured for Workload Identity Federation.

  2. Use the Security Token Service API to exchange the credential against a short-lived access token:

    Bash

    STS_TOKEN=$(curl https://sts.googleapis.com/v1/token \
    --data-urlencode "audience=//iam.googleapis.com/projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/providers/PROVIDER_ID" \
    --data-urlencode "grant_type=urn:ietf:params:oauth:grant-type:token-exchange" \
    --data-urlencode "requested_token_type=urn:ietf:params:oauth:token-type:access_token" \
    --data-urlencode "scope=https://www.googleapis.com/auth/cloud-platform" \
    --data-urlencode "subject_token_type=$SUBJECT_TOKEN_TYPE" \
    --data-urlencode "subject_token=$SUBJECT_TOKEN" | jq -r .access_token)
echo $STS_TOKEN

    PowerShell

    [System.Net.ServicePointManager]::SecurityProtocol = [System.Net.SecurityProtocolType]::Tls12
$StsToken = (Invoke-RestMethod `
    -Method POST `
    -Uri "https://sts.googleapis.com/v1/token" `
    -ContentType "application/json" `
    -Body (@{
        "audience"           = "//iam.googleapis.com/projects/PROJECT_NUMBER/locations/global/workloadIdentityPools/POOL_ID/providers/PROVIDER_ID"
        "grantType"          = "urn:ietf:params:oauth:grant-type:token-exchange"
        "requestedTokenType" = "urn:ietf:params:oauth:token-type:access_token"
        "scope"              = "https://www.googleapis.com/auth/cloud-platform"
        "subjectTokenType"   = $SubjectTokenType
        "subjectToken"       = $SubjectToken
    } | ConvertTo-Json)).access_token
Write-Host $StsToken

    Replace the following values:

    • PROJECT_NUMBER: Project number of the project that contains the workload identity pool
    • POOL_ID: ID of the workload identity pool
    • PROVIDER_ID: ID of the workload identity pool provider

  3. If you use service account impersonation, use the token from the Security Token Service to invoke the generateAccessToken method of the IAM Service Account Credentials API to obtain an access token.

Tokens for Cloud Run services

When accessing a Cloud Run service, you must use an ID token.

Bash

TOKEN=$(curl -0 -X POST https://iamcredentials.googleapis.com/v1/projects/-/serviceAccounts/SERVICE_ACCOUNT_EMAIL:generateIdToken \
    -H "Content-Type: text/json; charset=utf-8" \
    -H "Authorization: Bearer $STS_TOKEN" \
    -d @- <<EOF | jq -r .token
    {
        "audience": "SERVICE_URL"
    }
EOF
)
echo $TOKEN

PowerShell

$Token = (Invoke-RestMethod `
    -Method POST `
    -Uri "https://iamcredentials.googleapis.com/v1/projects/-/serviceAccounts/SERVICE_ACCOUNT_EMAIL:generateIdToken" `
    -Headers @{ "Authorization" = "Bearer $StsToken" } `
    -ContentType "application/json" `
    -Body (@{
        "audience" = "SERVICE_URL"
    } | ConvertTo-Json)).token
Write-Host $Token

Replace the following:

  • SERVICE_ACCOUNT_EMAIL: the email address of the service account.
  • SERVICE_URL: the URL of the service—for example, https://my-service-12345-us-central1.run.app. You can also set it to your custom service endpoint. For more information, see Understanding custom audiences.

Tokens for other platforms

When accessing another service, you must use an access token.

Bash

TOKEN=$(curl -0 -X POST https://iamcredentials.googleapis.com/v1/projects/-/serviceAccounts/SERVICE_ACCOUNT_EMAIL:generateAccessToken \
    -H "Content-Type: text/json; charset=utf-8" \
    -H "Authorization: Bearer $STS_TOKEN" \
    -d @- <<EOF | jq -r .accessToken
    {
        "scope": [ "https://www.googleapis.com/auth/cloud-platform" ]
    }
EOF
)
echo $TOKEN

PowerShell

$Token = (Invoke-RestMethod `
    -Method POST `
    -Uri "https://iamcredentials.googleapis.com/v1/projects/-/serviceAccounts/SERVICE_ACCOUNT_EMAIL:generateAccessToken" `
    -Headers @{ "Authorization" = "Bearer $StsToken" } `
    -ContentType "application/json" `
    -Body (@{
        "scope" = , "https://www.googleapis.com/auth/cloud-platform"
    } | ConvertTo-Json)).accessToken
Write-Host $Token

Replace the following:

  • SERVICE_ACCOUNT_EMAIL: the email address of the service account.

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