Google Cloud Identity and Access Management Concepts

External

• https://cloud.google.com/iam/docs/overview

Internal

• Google Cloud Identity and Access Management
• Google Cloud Authentication for Programmatic Access

Overview

IAM allows granting granular access to Google Cloud resources. It supports the security principle of least privilege, which states that nobody should have more permission that they actually need. IAM manages control by defining who (the identity) has what access (the role) for which resource. Permissions to access resources are not granted directed to end users, but to roles. Roles are granted to authenticated members. The association between what roles are granted to which members is defined in an IAM Policy. IAM policies are attached to resources. When an authenticated member attempts to access a resource, IAM checks the resource's policy to determine whether the action is permitted.

Identity Concepts

Member

A member can be a Google account, a service account, a Google group, a Google Workspace or a Cloud Identity domain.

Google Account

A Google Account represents a developer, an administrator, or any other person who interacts with Google Cloud. The identity of the member in this case is the email address that's associated with a Google account.

Service Account

https://cloud.google.com/iam/docs/service-accounts

A service account is an account for an application. Code running in Google Cloud runs as a "service account". The identity of the member in this case is the email address that's associated with the service account.

Service Account Credentials

Account

Same as Client Email.

Client ID

A digit-only string that uniquely identifies the service account. Optional.

Client Email

Required. Client email address of the service account. Also exposed as Account.

Private Key ID

Hexadecimal string private key ID.

Private Key

Required. Service account private key in PKCS8 PEM base64-encoded format.

Service Account Key File

A key file contains the private key a programmatic client that assumes the identity of a service account uses to authenticate to Google Cloud services. The service account key file can be generated with gcloud iam service-accounts key create.

{
  "type": "service_account",
  "project_id": "cellular-syntax-333333",
  "private_key_id": "2222222222222222222222222222222222222222",
  "private_key": "-----BEGIN PRIVATE KEY-----\nM...A=\n-----END PRIVATE KEY-----\n",
  "client_email": "test-sa@cellular-syntax-333333.iam.gserviceaccount.com",
  "client_id": "111111111111111111111",
  "auth_uri": "https://accounts.google.com/o/oauth2/auth",
  "token_uri": "https://oauth2.googleapis.com/token",
  "auth_provider_x509_cert_url": "https://www.googleapis.com/oauth2/v1/certs",
  "client_x509_cert_url": "https://www.googleapis.com/robot/v1/metadata/x509/test-sa%40cellular-syntax-333333.iam.gserviceaccount.com"
}

Service Account Operations

• Create a service account
• Give a service account permissions to a project
• Generate a key file for service account

Google Group

A Google group is a named collection of Google accounts and service accounts. Every Google group has a unique email address that's associated with the group. The identity of the member in this case is the email address that's associated with the Google group. Google groups are used to appy an access policy to a group of users. Google Groups don't have login credentials. Google Groups cannot be used to establish identity to make a request to access a resource.

Google Workspace domain

TODO: https://cloud.google.com/iam/docs/overview#g-suite-domain. The identity of the member in this case is the domain name that's associated with the Google Workspace.

Cloud Identity Domain

TODO: https://cloud.google.com/iam/docs/overview#cloud-identity-domain. The identity of the member in this case is the domain name that's associated with the Cloud Identity domain.

All Authenticated Users

The value allAuthenticatedUsers is a special identifier that represents all service accounts and all users on the internet who have authenticated with a Google Account. This identifier includes accounts that aren't connected to a Google Workspace or Cloud Identity domain, such as personal Gmail accounts. Users who aren't authenticated, such as anonymous visitors, aren't included. Some resource types do not support this member type.

All Users

The value allUsers is a special identifier that represents anyone who is on the internet, including authenticated and unauthenticated users. Some resource types do not support this member type.

Authenticated Member

Google Cloud Authentication for Programmatic Access

Google Cloud Authentication for Programmatic Access

Access Management Concepts

Resource

Google Cloud Platform Concepts | Resources

TODO: https://cloud.google.com/iam/docs/overview#resource

TODO Resource Hierarchy https://cloud.google.com/iam/docs/overview#resource-hierarchy

Role

TODO:

• https://cloud.google.com/iam/docs/overview#roles
• https://cloud.google.com/iam/docs/understanding-roles

A role is a collection of permissions. When a role is granted to a member, all the permissions that the role contains are granted to the member.

Permission

TODO: https://cloud.google.com/iam/docs/overview#permissions

A permission determines what operations are allowed on a resource.

Role Binding

A role binding is the association between a member and a role. Role bindings are listed in IAM policies.

Basic Roles

In production environments, do not grant the Owner, Editor, or Viewer roles.

Predefined Roles

TODO

Custom Roles

TODO

IAM Policy

TODO: https://cloud.google.com/iam/docs/overview#cloud-iam-policy

An IAM policy is a collection of role bindings. An IAM Policy is attached to a resource. When an authenticated member attempts to access a resource, IAM checks the resource's policy to determine whether the action is permitted.

For example, a service account (as member) can be given permissions to a project (a resource, by binding the service account to a role, via a role binding that is added to the project's IAM policy:

gcloud projects add-iam-policy-binding my-project-id \
  --member="serviceAccount:my-service-account@my-project-id.iam.gserviceaccount.com" \
  --role="roles/owner"

IAM Support for Google Cloud services

TODO: https://cloud.google.com/iam/docs/overview#cloud_iam_support_for_gcp_services

Consistency model for the IAM API

TODO: https://cloud.google.com/iam/docs/overview#consistency