Projects

This page describes the relationship between Google Cloud console projects and Cloud Storage resources. To learn more about Google Cloud console projects in general, read about Projects in Google Cloud.

What is a project?

A project organizes all your Google Cloud resources. All data in Cloud Storage belongs inside a project. A project consists of a set of users; a set of APIs; and billing, authentication, and monitoring settings for those APIs. So, for example, all of your Cloud Storage buckets and objects, along with user permissions for accessing them, reside in a project. You can have one project, or you can create multiple projects and use them to organize your Google Cloud resources, including your Cloud Storage data, into logical groups.

When to specify a project

Most of the time, you do not need to specify a project when performing actions in Cloud Storage; however you should include either the project ID or the project number in the following cases:

Console

  • When using Cloud Storage with the Google Cloud console, you're automatically associated with a project. You can change projects by using the drop-down menu at the top of the Google Cloud console window.

  • When first accessing a bucket that has enabled Requester Pays, you're prompted to select a project to bill requests to. You can subsequently change the billing project by using the Change project button located above the list of objects in the bucket.

Command line

The following commands use the project property set in your Google Cloud CLI configuration, unless you use the global --project flag in the command to specify a different project:

Use the global --billing-project flag, along with a project identifier, to indicate the project to charge for bucket access. This is required when accessing a bucket that has enabled Requester Pays and is optional otherwise.

Client libraries

The Cloud Storage Client Libraries require a project to be specified under the same circumstances as the JSON API.

JSON API

The following methods require you to specify a project:

The project is sent as a parameter in the request URL, as in the following example:

GET https://storage.googleapis.com/storage/v1/b?project=PROJECT_IDENTIFIER

  • To indicate a project to charge for bucket access, use the 'userProject' query paratemer, along with a project identifier, as in the following example:

    GET https://storage.googleapis.com/storage/v1/b?userProject=PROJECT_IDENTIFIER

    This query parameter is required when accessing a bucket that has enabled Requester Pays and is optional otherwise.

XML API

The following requests require you to specify a project, unless you have set a default project for interoperable access:

The project associated with these XML API requests is specified in the x-goog-project-id HTTP header, as in the following example:

x-goog-project-id: PROJECT_ID

The header is optional for other XML API requests.

  • To indicate a project to charge for bucket access, use the 'x-goog-user-project' header, along with a project ID, as in the following example:

    x-goog-user-project: PROJECT_ID

    This header is required when accessing a bucket that has enabled Requester Pays and is optional otherwise.

Projects and permissions

For each project, you use Identity and Access Management (IAM) to grant the ability to manage and work on your project. When you grant an IAM role to a principal, such as a user account, that principal obtains certain permissions that allow them to perform actions. When you grant a role at the project level, the access provided by the role applies to every bucket and object within the project. Alternatively, when you grant a role for an individual bucket, the access provided by the role is limited to just that bucket and the objects the bucket contains.

For a list of available roles that apply to Cloud Storage, as well as a discussion about how a special set of roles, called basic roles, apply to Cloud Storage, see Cloud Storage IAM roles.

For instructions for viewing, granting, and revoking a principal's roles at the bucket and project level, see Using IAM with projects.

Service accounts

Service accounts allow applications to authenticate and access Google Cloud resources and services. For example, you can create a service account that your Compute Engine instances use to access objects stored in Cloud Storage buckets. Service accounts are created within a project and have a unique email address that identifies them.

The following are examples of actions related to Cloud Storage that are often taken by service accounts that you create and manage:

Service agents

A service agent is a special type of service account that acts on behalf of a Google Cloud service. Cloud Storage uses a service agent for the following features:

The Cloud Storage service agent is not initially available when you make a project. Instead, it is automatically activated the first time it's accessed, either by one of the features listed above or when you request the service agent's name. The service agent must be activated prior to assigning permissions to it.

The following is an example email address for the Cloud Storage service agent associated with project number 123456789876:

service-123456789876@gs-project-accounts.iam.gserviceaccount.com

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