Manage Cloud Build resources with custom constraints

The Organization Policy Service gives you centralized, programmatic control over your organization's resources. As the organization policy administrator, you can define an organization policy, which is a set of restrictions called constraints that apply to Cloud Build resources and descendants of those resources in the Google Cloud resource hierarchy. You can enforce organization policies at the organization, folder, or project level.

The Organization Policy Service provides predefined constraints for various Cloud Build services. However, if you want more granular, customizable control over the specific fields that are restricted in your organization policies, you can also create custom organization policies.

Benefits

You can use a custom organization policy to allow or deny specific Cloud Build resources. For example, if a request to create or update a build trigger fails to satisfy custom constraint validation as set by your organization policy, the request will fail and an error will be returned to the caller.

Policy inheritance

By default, organization policies are inherited by the descendants of the resources on which you enforce the policy. For example, if you enforce a policy on a folder, Cloud Build enforces the policy on all projects in the folder. To learn more about this behavior and how to change it, see Hierarchy evaluation rules.

Pricing

The Organization Policy Service, including predefined and custom organization policies, is offered at no charge.

Before you begin

  1. Set up your project
    1. Sign in to your Google Cloud account. If you're new to Google Cloud, create an account to evaluate how our products perform in real-world scenarios. New customers also get $300 in free credits to run, test, and deploy workloads.

    2. In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

      Go to project selector

    3. Make sure that billing is enabled for your Google Cloud project.

    4. Enable the Cloud Build API.

      Enable the API

    5. Install the Google Cloud CLI.

    6. To initialize the gcloud CLI, run the following command: 

      gcloud init

    7. In the Google Cloud console, on the project selector page, select or create a Google Cloud project.

      Go to project selector

    8. Make sure that billing is enabled for your Google Cloud project.

    9. Enable the Cloud Build API.

      Enable the API

    10. Install the Google Cloud CLI.

    11. To initialize the gcloud CLI, run the following command: 

      gcloud init
    12. Ensure that you know your organization ID.

Required roles

To get the permissions that you need to manage organization policies, ask your administrator to grant you the Organization policy administrator (roles/orgpolicy.policyAdmin) IAM role on the organization resource. For more information about granting roles, see Manage access to projects, folders, and organizations.

You might also be able to get the required permissions through custom roles or other predefined roles.

You also need to add required roles to create Cloud Build to your user account. See Configuring access to Cloud Build resources. To learn more about IAM roles associated with Cloud Build, see IAM roles and permissions.

Create a custom constraint

You can create a custom constraint by using a YAML file to define the resources, methods, conditions, and actions that are subject to the constraint. These are specific to the service on which you're enforcing the organization policy. Conditions for your custom constraints must be defined using Common Expression Language. See the GitHub page about Common Expression Language (CEL). For more information about how to build conditions in custom constraints using CEL, see the CEL section of Creating and managing custom constraints.

Use the following template to create a YAML file for a custom constraint:

name: organizations/ORGANIZATION_ID/customConstraints/CONSTRAINT_NAME
resourceTypes:
- cloudbuild.googleapis.com/RESOURCE_NAME
methodTypes:
- CREATE
- UPDATE
condition: "CONDITION"
actionType: ACTION
displayName: DISPLAY_NAME
description: DESCRIPTION

Replace the following:

  • ORGANIZATION_ID: your organization ID, such as 123456789.

  • CONSTRAINT_NAME: the name you want for your new custom constraint. A custom constraint must start with custom., and can only include uppercase letters, lowercase letters, or numbers, for example, custom.enableBuildTrigger. The maximum length of this field is 70 characters, not counting the prefix, for example, organizations/123456789/customConstraints/custom.allowConstraint.

  • RESOURCE_NAME: the name (not the URI) of the Cloud Build resource containing the object and field you want to restrict. For example, BuildTrigger.

  • CONDITION: a CEL condition that is written against a representation of a supported service resource. This field has a maximum length of 1000 characters. See Supported resources for more information about the resources available to write conditions against. For example, "resource.github.name.contains('cloudbuild')".

  • ACTION: the action to take if the condition is met. This can be either ALLOW or DENY.

  • DISPLAY_NAME: a human-friendly name for the constraint. This field has a maximum length of 200 characters.

  • DESCRIPTION: a human-friendly description of the constraint to display as an error message when the policy is violated. This field has a maximum length of 2000 characters.

For more information about how to create a custom constraint, see Creating and managing custom organization policies.

Set up a custom constraint

After you have created the YAML file for a new custom constraint, you must set it up to make it available for organization policies in your organization. To set up a custom constraint, use the gcloud org-policies set-custom-constraint command: 
gcloud org-policies set-custom-constraint CONSTRAINT_PATH
Replace CONSTRAINT_PATH with the full path to your custom constraint file. For example, /home/user/customconstraint.yaml. Once completed, your custom constraints are available as organization policies in your list of Google Cloud organization policies. To verify that the custom constraint exists, use the gcloud org-policies list-custom-constraints command: 
gcloud org-policies list-custom-constraints --organization=ORGANIZATION_ID
Replace ORGANIZATION_ID with the ID of your organization resource. For more information, see Viewing organization policies.

Enforce a custom organization policy

You can enforce a boolean constraint by creating an organization policy that references it, and then applying that organization policy to a Google Cloud resource.

Console

  1. In the Google Cloud console, go to the Organization policies page.

    Go to Organization policies

  2. From the project picker, select the project for which you want to set the organization policy.
  3. From the list on the Organization policies page, select your constraint to view the Policy details page for that constraint.
  4. To configure the organization policy for this resource, click Manage policy.
  5. On the Edit policy page, select Override parent's policy.
  6. Click Add a rule.
  7. In the Enforcement section, select whether enforcement of this organization policy is on or off.
  8. Optional: To make the organization policy conditional on a tag, click Add condition. Note that if you add a conditional rule to an organization policy, you must add at least one unconditional rule or the policy cannot be saved. For more information, see Setting an organization policy with tags.
  9. If this is a custom constraint, you can click Test changes to simulate the effect of this organization policy. For more information, see Test organization policy changes with Policy Simulator.
  10. To finish and apply the organization policy, click Set policy. The policy requires up to 15 minutes to take effect.

gcloud

To create an organization policy that enforces a boolean constraint, create a policy YAML file that references the constraint: 

      name: projects/PROJECT_ID/policies/CONSTRAINT_NAME
      spec:
        rules:
        - enforce: true

Replace the following:

  • PROJECT_ID: the project on which you want to enforce your constraint.
  • CONSTRAINT_NAME: the name you defined for your custom constraint. For example, custom.enableBuildTrigger.

To enforce the organization policy containing the constraint, run the following command: 

    gcloud org-policies set-policy POLICY_PATH

Replace POLICY_PATH with the full path to your organization policy YAML file. The policy requires up to 15 minutes to take effect.

Test a custom constraint

To test a custom constraint, run a gcloud command that attempts to complete a task blocked by your constraint.

For example, assume that a constraint requires that GitHub trigger names contain "cloudbuild". You could test this constraint by running the gcloud builds triggers create github command with another trigger name as demonstrated in the following snippet:

gcloud builds triggers create github --name=github-trigger \
    --repo-owner=some-owner \
    --repo-name=some-repo \
    --branch-pattern=main \
    --build-config=cloudbuild.yaml \
    --project=my-project \

The output is similar to the following:

Operation denied by custom org policies: ["customConstraints/custom.enableBuildTrigger": "GitHub trigger name must include "cloudbuild"."]

Cloud Build supported resources and operations

The following Cloud Build custom constraint fields are available to use when you create or update a Cloud Build resources.

Note that the constraint on Builds is not enforced on Builds triggered by trigger.

  • Cloud Build BitbucketServerConfig
    • resource.name
    • resource.hostUrl
    • resource.secrets.adminAccessTokenVersionName
    • resource.secrets.readAccessTokenVersionName
    • resource.secrets.webhookSecretVersionName
    • resource.username
    • resource.apiKey
    • resource.peeredNetwork
    • resource.sslCa
    • resource.peeredNetworkIpRange
  • Cloud Build WorkerPool configuration
    • resource.displayName
    • resource.annotations
    • resource.privatePoolV1Config.workerConfig.machineType
    • resource.privatePoolV1Config.workerConfig.diskSizeGb
    • resource.privatePoolV1Config.networkConfig.peeredNetwork
    • resource.privatePoolV1Config.networkConfig.egressOpetion
    • resource.privatePoolV1Config.networkConfig.peeredNetworkIpRange
  • Cloud Build BuildTrigger configuration
    • resource.tags
    • resource.resourceName
    • resource.description
    • resource.name
    • resource.tags
    • resource.triggerTemplate.projectId
    • resource.triggerTemplate.repoName
    • resource.triggerTemplate.branchName
    • resource.triggerTemplate.tagName
    • resource.triggerTemplate.commitSha
    • resource.triggerTemplate.dir
    • resource.triggerTemplate.invertRegex
    • resource.triggerTemplate.substitutions
    • resource.github.owner
    • resource.github.name
    • resource.github.enterpriseConfigResourceName
    • resource.pubsubConfig.topic
    • resource.pubsubConfig.serviceAccountEmail
    • resource.webhookConfig.secret
    • resource.bitbucketServerTriggerConfig.repoSlug
    • resource.bitbucketServerTriggerConfig.projectKey
    • resource.bitbucketServerTriggerConfig.pullRequest.branch
    • resource.bitbucketServerTriggerConfig.pullRequest.commentControl
    • resource.bitbucketServerTriggerConfig.pullRequest.invertRegex
    • resource.bitbucketServerTriggerConfig.push.branch
    • resource.bitbucketServerTriggerConfig.push.tag
    • resource.bitbucketServerTriggerConfig.push.invertRegex
    • resource.gitlabEnterpriseEventsConfig.projectNamespace
    • resource.gitlabEnterpriseEventsConfig.pullRequest.branch
    • resource.gitlabEnterpriseEventsConfig.pullRequest.commentControl
    • resource.gitlabEnterpriseEventsConfig.pullRequest.invertRegex
    • resource.gitlabEnterpriseEventsConfig.push.branch
    • resource.gitlabEnterpriseEventsConfig.push.tag
    • resource.gitlabEnterpriseEventsConfig.push.invertRegex
    • resource.gitlabEnterpriseEventsConfig.gitlabConfigResource
    • resource.disabled
    • resource.substitutions
    • resource.ignoredFiles
    • resource.includedFiles
    • resource.sourceToBuild.uri
    • resource.sourceToBuild.repository
    • resource.sourceToBuild.ref
    • resource.sourceToBuild.repoType
    • resource.sourceToBuild.githubEnterpriseConfig
    • resource.approvalConfig.approvalRequired
    • resource.filter
    • resource.serviceAccount
    • resource.eventType
    • resource.includeBuildLogs
    • resource.repositoryEventConfig.repository
    • resource.repositoryEventConfig.pullRequest.branch
    • resource.repositoryEventConfig.pullRequest.commentControl
    • resource.repositoryEventConfig.pullRequest.invertRegex
    • resource.repositoryEventConfig.push.branch
    • resource.repositoryEventConfig.push.tag
    • resource.repositoryEventConfig.push.invertRegex
  • Cloud Build GitHubEnterpriseConfig configuration
    • resource.name
    • resource.hostUrl
    • resource.appId
    • resource.name
    • resource.webhookKey
    • resource.peeredNetwork
    • resource.secrets.privateKeyVersionName
    • resource.secrets.webhookSecretVersionName
    • resource.secrets.oauthSecretVersionName
    • resource.secrets.oauthClientIdVersionName
    • resource.displayName
    • resource.sslCa

Example custom organization policies for common use cases

The following table provides the syntax of some custom organization policies that you might find useful:

Description Constraint syntax
Only allow creating Pub/Sub trigger that listens on topics that contain "cloud-builds" 

    name: organizations/ORGANIZATION_ID/customConstraints/custom.enableCloudBuildPubsubTrigger
    resourceTypes:
    - cloudbuild.googleapis.com/BuildTrigger
    methodTypes:
    - CREATE
    condition: "resource.pubsubConfig != null && resource.pubsubConfig.topic.contains('cloud-builds')"
    actionType: ALLOW
    displayName: Enable creating Pub/Sub trigger that listens on topics that contain "cloud-builds".
    description: Only allow creating Pub/Sub trigger that listens on topics that contain "cloud-builds".
  • ORGANIZATION_ID: your organization ID, such as 123456789.

What's next