Impersonating Tokens with Their Respective Service Accounts in GCP
Access tokens are crucial for authenticating and authorizing various services within Google Cloud Platform (GCP). Typically, these tokens are generated using admin account credentials, allowing them to act as global tokens. However, there might be scenarios where you need to generate access tokens for specific service accounts. This can be achieved through impersonation.
What is Impersonation?
Impersonation allows one service account to assume the identity of another, enabling it to perform actions on behalf of the impersonated account. This is particularly useful when you need to segregate duties and manage permissions more granularly.
How to Print an Access Token Using Impersonation
1. Login to your google account using this command:
google auth login
2. To generate an access token for a service account using impersonation, you can use the gcloud command-line tool(google cloud sdk shell). Here’s the command you need:
gcloud auth print-access-token --impersonate-service-account=YOUR_SERVICE_ACCOUNT
Replace YOUR_SERVICE_ACCOUNT with the email address of the service account you wish to impersonate.
Prerequisites for Generating the Token
Before you can generate the access token through impersonation, certain prerequisites must be met:
1. Principals and Roles
To enable impersonation, you need to assign specific roles to the service account. Here’s a step-by-step guide:
- Enable the Service Account Token Creator Role:
- At the owner level, you must assign the Service Account Token Creator role to the service account that will perform the impersonation. This role allows the service account to generate access tokens.
- You can do this through the GCP Console or using the gcloud command-line tool.
- Navigate to the IAM & Admin section.
- Select the appropriate service account.
- Assign the Service Account Token Creator role.
Here is the documentation for better understanding :
Use service account impersonation
Conclusion
By following these steps, you can generate access tokens for specific service accounts using impersonation. Properly configuring roles and permissions ensures that only authorized accounts can perform actions, maintaining the integrity and security of your cloud resources.