Creating Cloud IAM policies

This page explains how to create Cloud Identity and Access Management (Cloud IAM) policies for authorization in Google Kubernetes Engine (GKE).

Overview

Every Google Cloud, GKE, and Kubernetes API call requires that the account making the request has the necessary permissions. By default, no one except you can access your project or its resources. You can use Cloud IAM to manage who can access your project and what they are allowed to do. Cloud IAM permissions work alongside Kubernetes RBAC, which provides granular access controls for specific objects in a cluster or namespace. Cloud IAM has a stronger focus on permissions at the level of the Google Cloud project and organization, though it does provide several predefined roles specific to GKE.

To grant users and service accounts access to your Google Cloud project, you add them as project team members, then assign roles to the team members. Roles define which Google Cloud resources an account can access and which operations they can perform.

In GKE, you can use Cloud IAM to manage which users and service accounts can access, and perform operations in, your clusters.

Before you begin

Before you start, make sure you have performed the following tasks:

Set up default gcloud settings using one of the following methods:

  • Using gcloud init, if you want to be walked through setting defaults.
  • Using gcloud config, to individually set your project ID, zone, and region.

Using gcloud init

If you receive the error One of [--zone, --region] must be supplied: Please specify location, complete this section.

  1. Run gcloud init and follow the directions:

    gcloud init

    If you are using SSH on a remote server, use the --console-only flag to prevent the command from launching a browser:

    gcloud init --console-only
  2. Follow the instructions to authorize gcloud to use your Google Cloud account.
  3. Create a new configuration or select an existing one.
  4. Choose a Google Cloud project.
  5. Choose a default Compute Engine zone.

Using gcloud config

  • Set your default project ID:
    gcloud config set project project-id
  • If you are working with zonal clusters, set your default compute zone:
    gcloud config set compute/zone compute-zone
  • If you are working with regional clusters, set your default compute region:
    gcloud config set compute/region compute-region
  • Update gcloud to the latest version:
    gcloud components update

Interaction with Kubernetes RBAC

Kubernetes' native role-based access control (RBAC) system also manages access to your cluster. RBAC controls access on a cluster and namespace level, while Cloud IAM works on the project level.

Cloud IAM and RBAC can work in concert, and an entity must have sufficient permissions at either level to work with resources in your cluster.

Cloud IAM Roles

The following sections describe the Cloud IAM Roles available in Google Cloud.

Predefined GKE Roles

Cloud IAM provides predefined Roles that grant access to specific Google Cloud resources and prevent unauthorized access to other resources.

Cloud IAM offers the following predefined roles for GKE:

Role Title Description Lowest resource
roles/container.admin Kubernetes Engine Admin

Provides access to full management of clusters and their Kubernetes API objects.

To set a service account on nodes, you must also grant the Service Account User role (roles/iam.serviceAccountUser).

Project
roles/container.clusterAdmin Kubernetes Engine Cluster Admin

Provides access to management of clusters.

To set a service account on nodes, you must also grant the Service Account User role (roles/iam.serviceAccountUser).

Project
roles/container.clusterViewer Kubernetes Engine Cluster Viewer Get and list access to GKE Clusters.
roles/container.developer Kubernetes Engine Developer Provides access to Kubernetes API objects inside clusters. Project
roles/container.hostServiceAgentUser Kubernetes Engine Host Service Agent User Allows the Kubernetes Engine service account in the host project to configure shared network resources for cluster management. Also gives access to inspect the firewall rules in the host project.
roles/container.viewer Kubernetes Engine Viewer Provides read-only access to GKE resources. Project

To learn about permissions granted by each Cloud IAM role, refer to Permissions granted by Cloud IAM roles.

Primitive Cloud IAM roles

Primitive Cloud IAM roles grant users global, project-level access to all Google Cloud resources. To keep your project and clusters secure, use predefined Roles whenever possible.

To learn more about primitive roles, refer to Primitive roles in the Cloud IAM documentation.

Service Account User role

Service Account User grants a Google Cloud user account the permission to perform actions as though a service account were performing them.

  • Granting the iam.serviceAccountUser role to a user for a project gives the user all of the roles granted to all service accounts in the project, including service accounts that may be created in the future.

  • Granting the iam.serviceAccountUser role to a user for a specific service account gives a user all of the roles granted to that service account.

This role includes the following permissions:

  • iam.serviceAccounts.actAs
  • iam.serviceAccounts.get
  • iam.serviceAccounts.list
  • resourcemanager.projects.get
  • resourcemanager.projects.list

For more information about the ServiceAccountUser role, see ServiceAccountUser in the Cloud IAM documentation.

The following command shows the syntax for granting the Service Account User role:

gcloud iam service-accounts add-iam-policy-binding \
  sa-name@project-id.iam.gserviceaccount.com \
  --member=user:user \
  --role=roles/iam.serviceAccountUser

Host Service Agent User role

The Host Service Agent User role is only used in Shared VPC clusters. This role includes the following permissions:

  • compute.firewalls.get
  • container.hostServiceAgent.*

Custom roles

If predefined roles don't meet your needs, you can create custom roles with permissions that you define.

To learn how to create and assign custom roles, refer to Creating and managing custom roles.

Viewing permissions granted by Cloud IAM roles

You can view the permissions granted by each Role using the gcloud command-line tool or Cloud Console.

gcloud

To view the permissions granted by a specific role, run the following command:

gcloud iam roles describe roles/role

where role is any Cloud IAM role. GKE roles are prefixed with roles/container.:

For example:

gcloud iam roles describe roles/container.admin

Console

To view the permissions granted by a specific Role, perform the following steps:

  1. Visit the Roles section of Cloud Console's Cloud IAM page.

    Visit the Cloud IAM page

  2. To see the roles for GKE, in the Filter table field, enter Kubernetes Engine.

  3. Select the desired role. The description of the role, and a list of assigned permissions displays.

Managing Cloud IAM roles

To learn how to manage Cloud IAM roles and permissions for human users, refer to Granting, changing, and revoking access to project members in the Cloud IAM documentation.

For service accounts, refer to Granting roles to service accounts.

Examples

Here are a few examples of how Cloud IAM works with GKE:

  • A new employee has joined a company. They need to be added to the Google Cloud project, but they only need to view the project's clusters and other Google Cloud resources. The project owner assigns them the project-level Compute Viewer role. This role provides read-only access to get and list nodes, which are Compute Engine resources.
  • The employee is working in operations, and they need to update a cluster using gcloud or Google Cloud Console. This operation requires the container.clusters.update permission, so the project owner assigns them the Kubernetes Engine Cluster Admin role. The employee now has the permissions granted by both the Kubernetes Engine Cluster Admin and Compute Viewer roles.
  • The employee needs to investigate why a Deployment is having issues. They need to run kubectl get pods to see Pods running in the cluster. The employee already has the Compute Viewer role, which is not sufficient for listing Pods. The employee needs the Kubernetes Engine Viewer role.
  • The employee needs to create a new cluster. The project owner grants the employee the Service Account User role for the project-number-compute@developer.gserviceaccount.com service account, so that the employee's account can access Compute Engine's default service account. This service account has the Editor role, which provides a broad set of permission.

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