Access Control

You can set access control using roles at the project level. Assign a role to a project member or service account to determine the level of access to your Google Cloud Platform project and its resources. By default, all Google Cloud Platform projects come with a single user: the original project creator. No other users have access to the project, and therefore, access to functions, until a user is added as a project team member.

Access control for users

You can add users as team members to your project and assign them roles using Identity and Access Management (IAM).

Cloud Functions supports the primitive roles Editor, Owner, and Viewer, which grant the following permissions:

• Editor and Owner: Read and write access to all functions-related resources. Allows users to deploy, update, and delete functions. Additional access to other resources in the project.
• Viewer: Read-only access to functions and locations. Allows users to list functions and see their details, but does not allow them to view the source code. Additional access to other resources in the project.

Cloud Functions also supports the Cloud Functions curated roles Developer and Viewer, which grant the following permissions:

• Developer: Read and write access to all functions-related resources. Allows users to deploy, update, and delete functions. No access to other resources in the project.
• Viewer: Read-only access to functions and locations. Allows users to list functions and see their details, but does not allow them to view the source code. No access to other resources in the project.

Runtime service account

At runtime, Cloud Functions defaults to using the App Engine default service account ([e-mail]), which has the Editor role on the project. You can change the roles of this service account to limit or extend the permissions for your running functions. You can also change which service account is used by providing a non-default service account on a per-function basis.

To learn more about service accounts, see the Service Accounts documentation.

Cloud Functions service account

For administrative actions on your project during the creation, updating, or deletion of functions, the Cloud Functions service uses the Google Cloud Functions service agent service account ([e-mail]).

By default, this service account has the cloudfunctions.serviceAgent role on your project. Creating, updating, and deleting functions may fail if you change this account's permissions.

Note: Authenticating as the runtime service account from inside your function may fail if you change the Cloud Functions service account's permissions.

The cloudfunctions.serviceAgent role has the following permissions:

Permission	Description
pubsub.subscriptions.*	Manage subscriptions in the user's project.
pubsub.topics.create	Create a new topic once a function is deployed.
pubsub.topics.attachSubscription	Attach subscription to an existing topic.
pubsub.topics.get	Get the existing topic on which the function should be triggered.
iam.serviceAccounts.actAs	Run the function as the runtime service account.
iam.serviceAccounts.{getAccessToken, signBlob}	Ability to get runtime service account credentials.
resourcemanager.projects.getIamPolicy	Determine the function origin.
firebasedatabase.instances.{get, update}	Create functions triggered by the Firebase Realtime Database.
storage.buckets.{get, update}, resourcemanager.projects.get	Create functions triggered by a Cloud Storage bucket.

You can reset this service account to the default role by removing whatever role it currently has, and adding the Cloud Functions Service Agent role:

gcloud projects add-iam-policy-binding PROJECT_ID \
  --member serviceAccount:[e-mail] \
  --role roles/cloudfunctions.serviceAgent

Troubleshooting permission errors

If you get permission errors when you deploy, update, delete, or execute functions in your project, perform the following steps:

1. Make sure that you have the Editor or Owner role on your project, or that you are using the Cloud Functions Developer role.
   If you are using the Cloud Functions Developer role, also ensure that you have granted the user the IAM Service Account User role.
2. Verify that the Cloud Functions service account ([e-mail]) has the cloudfunctions.serviceAgent role for your project.
3. Ensure that you have permissions for trigger sources, such as Pub/Sub or Cloud Storage.

If you get an ”insufficient permissions” error, or have other authentication problems when you run your functions, make sure that the runtime service account has the correct permissions to access the resources your functions need, then follow steps 2 and 3 above.

If you get a ”service unavailable” error during deployment, make sure that the runtime service account [e-mail] exists in your project. This thread on Stack Overflow discusses how to recreate this service account if it was deleted.