Managing IAM permissions for service accounts in Google Cloud is a critical aspect of configuring access and security. Service accounts are special accounts used by applications, virtual machines, and other workloads to authenticate and access Google Cloud resources.
To manage IAM permissions for …Managing IAM permissions for service accounts in Google Cloud is a critical aspect of configuring access and security. Service accounts are special accounts used by applications, virtual machines, and other workloads to authenticate and access Google Cloud resources.
To manage IAM permissions for service accounts, you work with three key concepts: roles, bindings, and policies. Roles define a collection of permissions that determine what actions can be performed on resources. You can assign predefined roles like Service Account User, Service Account Admin, or Service Account Token Creator, or create custom roles for specific needs.
There are two perspectives when managing service account permissions. First, you control what the service account itself can do by granting it roles on various resources. For example, giving a service account the Storage Object Viewer role allows it to read objects in Cloud Storage buckets. Second, you control who can use or manage the service account by granting users roles on the service account resource.
You can manage these permissions through the Google Cloud Console, gcloud CLI, or the IAM API. Using gcloud, commands like 'gcloud projects add-iam-policy-binding' and 'gcloud iam service-accounts add-iam-policy-binding' are commonly used.
Best practices include following the principle of least privilege, granting only necessary permissions. Avoid using primitive roles like Owner or Editor for service accounts. Instead, use more granular predefined or custom roles. Regularly audit service account permissions using Cloud Asset Inventory or IAM Recommender.
Service account impersonation allows users or other service accounts to act as a target service account when they have the Service Account Token Creator role. This provides flexible access patterns while maintaining security controls.
Key management is also essential. You can create and rotate service account keys, though using attached service accounts or Workload Identity Federation is preferred over managing key files manually.
Managing IAM Permissions of a Service Account
Why It Is Important
Service accounts are essential for enabling applications, virtual machines, and other Google Cloud resources to authenticate and interact with Google Cloud APIs. Properly managing IAM permissions for service accounts is critical for maintaining security, implementing the principle of least privilege, and ensuring that automated workloads have appropriate access to resources. Misconfigured service account permissions can lead to security vulnerabilities or operational failures.
What Is a Service Account?
A service account is a special type of Google Cloud account that belongs to an application or compute workload rather than an individual user. Service accounts are identified by their email address, which follows the format: service-account-name@project-id.iam.gserviceaccount.com. There are three types of service accounts:
• Default service accounts - Automatically created when certain services are enabled • User-managed service accounts - Created by users for specific purposes • Google-managed service accounts - Created and managed by Google for internal processes
How IAM Permissions Work for Service Accounts
Service accounts interact with IAM in two ways:
1. As an Identity (Principal) Service accounts can be granted IAM roles to access resources. You assign roles to service accounts just like you would assign roles to users. For example, granting the roles/storage.objectViewer role allows the service account to read objects in Cloud Storage buckets.
2. As a Resource Service accounts themselves are resources that can be managed. Users need specific permissions to create, modify, or impersonate service accounts. Key roles include: • roles/iam.serviceAccountUser - Allows attaching service accounts to resources • roles/iam.serviceAccountAdmin - Full control over service accounts • roles/iam.serviceAccountTokenCreator - Allows creating tokens for service accounts
Managing Service Account Permissions
Granting Roles to Service Accounts:
Using gcloud CLI: gcloud projects add-iam-policy-binding PROJECT_ID --member=serviceAccount:SA_EMAIL --role=ROLE_NAME
Granting Users Permission to Use Service Accounts:
gcloud iam service-accounts add-iam-policy-binding SA_EMAIL --member=user:USER_EMAIL --role=roles/iam.serviceAccountUser
Best Practices
• Apply the principle of least privilege - Grant only necessary permissions • Use custom roles when predefined roles are too broad • Regularly audit service account permissions using Policy Analyzer • Disable unused service accounts rather than deleting them initially • Use short-lived credentials when possible • Avoid granting the Owner or Editor roles to service accounts
Exam Tips: Answering Questions on Managing IAM Permissions of a Service Account
• Understand the difference between acting as a service account versus managing it - Questions may test whether you know that serviceAccountUser allows using the account while serviceAccountAdmin allows managing it
• Know the scope of permissions - Service accounts can be granted permissions at project, folder, or organization levels
• Recognize least privilege scenarios - When asked about the most secure approach, choose options that grant minimal necessary permissions
• Remember service account impersonation - Users need the serviceAccountTokenCreator role to generate access tokens for a service account
• Identify default service accounts - Know that default service accounts often have excessive permissions (Editor role) and should be replaced with custom service accounts
• Watch for key management questions - Understand the difference between Google-managed keys and user-managed keys
• Pay attention to resource hierarchy - Permissions granted at higher levels (organization, folder) are inherited by lower levels (projects, resources)