Cloud Build lets you create triggers to build from repositories hosted on [GitHub](https://github.com/about/). You can execute builds in response to events such as commit pushes or merge requests associated with your GitHub repository. This page explains how you can enable build triggers for a GitHub instance. For more information, see [Cloud Build triggers](https://docs.cloud.google.com/build/docs/triggers.md.txt) and [Cloud Build repositories](https://docs.cloud.google.com/build/docs/repositories.md.txt). ## Before you begin Follow the instructions to [connect to a GitHub host](https://docs.cloud.google.com/build/docs/automating-builds/github/connect-host-github-enterprise.md.txt). - Enable the Cloud Build API, if it is not already enabled. **Roles required to enable APIs** To enable APIs, you need the `serviceusage.services.enable` permission. If you created the project, then you likely already have this permission through the Owner role (`roles/owner`). Otherwise, you can get this permission through the Service Usage Admin role (`roles/serviceusage.serviceUsageAdmin`). [Learn how to grant roles](https://docs.cloud.google.com/iam/docs/granting-changing-revoking-access.md.txt). [Enable the API](https://console.cloud.google.com/apis/enableflow?apiid=cloudbuild.googleapis.com&redirect=https://cloud.google.com/build/docs/automating-builds/github/build-repos-from-github) To create a trigger for a GitHub repository, you must have a connection between Google Cloud and your repository. To create a connection through the GitHub app in Google Cloud, see [Connect to a GitHub repository](https://docs.cloud.google.com/build/docs/automating-builds/github/connect-repo-github.md.txt). ## Create a GitHub trigger This section explains how you can create a trigger and link it to your GitHub installation. ### Google Cloud console To create GitHub triggers using the Google Cloud console, do the following: 1. Open the **Triggers** page in the Google Cloud console. [Open the Triggers page](https://console.cloud.google.com/cloud-build/triggers) 2. Select your Google Cloud project and click **Open**. 3. Click **Create trigger**. 4. Enter the following trigger settings: - **Name**: Enter a name for your trigger. - **Region** : Select the [region](https://docs.cloud.google.com/build/docs/locations.md.txt) for your trigger. - If the build config file associated with the trigger specifies a [private pool](https://docs.cloud.google.com/build/docs/private-pools/private-pools-overview.md.txt), then Cloud Build uses the private pool to run your build. In this case, the region you specify in your trigger must match the region where you created your private pool. - If the build config file associated with the trigger **doesn't** specify a private pool, then Cloud Build uses the default pool to run your build in the same region as your trigger.
- **Description** (optional): Enter a description for your trigger. - **Event**: Select the repository event to invoke your trigger. - **Push to a branch**: Set your trigger to start a build on commits to a particular branch. - **Push new tag**: Set your trigger to start a build on commits that contain a particular tag. - **Pull request**: Set your trigger to start a build on commits to a pull request. > [!NOTE] > **Note:** Running builds initiated by a GitHub App pull request trigger are canceled when you close the pull request associated with your build. Running builds and builds that have not been started yet won't be canceled when merging a pull request. - **Source**: Configure information about your GitHub repository: - **Repository service**: Select Cloud Build. - **Repository generation** : Select **2nd generation** as your source. > [!NOTE] > **Note:** The region of your repository must match the region of your trigger. - **Repository**: From the list of available repositories, select the repository. - **Branch** or **Tag** : Specify a regular expression with the branch or tag value to match. For information on acceptable regular expression syntax, see [RE2 syntax](https://github.com/google/re2/wiki/Syntax). - **Comment control** : If you selected **Pull request** as your **Event**, choose one of the following options to control whether a build is automatically executed by the trigger: - **Required except for owners and collaborators** : When a pull request is created or updated by a repository owner or collaborator, builds are automatically executed by the trigger. If an external contributor initiates the action, builds are executed only after an owner or collaborator comments `/gcbrun` on the pull request. - **Required** : When a pull request is created or updated by any contributor, builds are executed only after an owner or collaborator comments `/gcbrun` on the pull request. Builds are executed each time a change to a pull request is made. - **Not required**: When a pull request is created or updated by any contributor, builds are automatically be executed by triggers. > [!WARNING] > **Warning:** Any user with read access to the repository can submit a pull request, which may execute a build that includes changes to the source code in the pull request. To disable this behavior, we recommend using [manual approvals](https://docs.cloud.google.com/build/docs/automating-builds/approve-builds) to gate builds when making pull requests on public repositories. You can also learn more about the [build-time privileges of triggers](https://docs.cloud.google.com/build/docs/cloud-build-service-account.md.txt#build_triggers). - **Configuration**: Select the build config file located in your remote repository or create an inline build config file to use for your build. - **Type** : Select the type of configuration to use for your build. - **Autodetected** : Cloud Build autodetects your configuration type if you have a `cloudbuild.yaml` or `Dockerfile` in your repository. - **Cloud Build configuration file (yaml or json)**: Use a build config file for your configuration. - **Dockerfile** : Use a `Dockerfile` for your configuration. - **Buildpacks** : Use [buildpacks](https://buildpacks.io/) for your configuration. - **Location**: Specify the location for your configuration. - **Repository** : If your config file is located in your remote repository, provide the location of your [build config file](https://docs.cloud.google.com/build/docs/build-config) or the `Dockerfile` directory and a name for the resulting image. If your configuration is a `Dockerfile`, you can optionally provide a timeout for your build. When you've provided the `Dockerfile` and image name, you'll see a preview of the `docker build` command that your build will execute. - **Inline** : If you selected **Cloud Build configuration file (yaml or json)** as your configuration option, you can specify your build config inline. Click **Open Editor** to write your build config file in the Google Cloud console using YAML or JSON syntax. Click **Done** to save your build config. > [!NOTE] > **Note:** Inline build configuration support is not available for `Dockerfile`. - **Substitution variables** (optional): If you selected the Cloud Build config file as your build config option, you can choose to define trigger-specific substitution variables using this field. For example, say you're creating multiple triggers where each trigger deploys your app to a specific environment. You can specify that your app is deployed to an environment in your build config file and then use this field to define substitution variables specifying which environment this trigger should deploy to. For information on specifying substitution values in build config files, see [Substituting variable values](https://docs.cloud.google.com/build/docs/configuring-builds/substitute-variable-values.md.txt). - **Build logs** (optional): Check the box to send build logs to GitHub. To learn how to view build logs, see [Viewing build logs](https://docs.cloud.google.com/build/docs/securing-builds/store-view-build-logs#viewing_build_logs). - **Service account**: Select the service account to use when invoking your trigger. If your organization policy allows using the legacy Cloud Build service account, you can leave this blank to use the legacy service account. Otherwise, you must select the specific service account to use, even if it's the Compute Engine default service account. > [!NOTE] > **Note:** Only the service account specified on your trigger is used for builds executed by triggers. If you specified a service account in your build config, it's ignored during build execution when using triggers. 5. Click **Create** to save your build trigger. To create GitHub triggers using `gcloud` commands, see the `gcloud` commands for [Creating a build trigger](https://docs.cloud.google.com/build/docs/automating-builds/create-manage-triggers.md.txt). ### gcloud CLI To create GitHub triggers using `gcloud` commands, run the following command: gcloud builds triggers create github \ --name=TRIGGER_NAME \ --repository=projects/PROJECT_ID/locations/REGION/connections/CONNECTION_NAME/repositories/REPO_NAME \ --branch-pattern=BRANCH_PATTERN # or --tag-pattern=TAG_PATTERN \ --build-config=BUILD_CONFIG_FILE \ --region=REGION \ --service-account=SERVICE-ACCOUNT Where: - TRIGGER_NAME is the name of your trigger. - PROJECT_ID is your Google Cloud project ID. - REGION is the [region](https://docs.cloud.google.com/build/docs/locations.md.txt) of your trigger. - CONNECTION_NAME is the name of your GitHub connection. - REPO_NAME is the name of your repository - BRANCH_PATTERN is the branch name in your repository to invoke the build on. - TAG_PATTERN is the tag name in your repository to invoke the build on. - BUILD_CONFIG_FILE is the path to your build configuration file. - SERVICE-ACCOUNT is the service account to use for trigger and build operations. ### API To create a GitHub trigger with the API, use the following JSON template: ```json { "filename": "cloudbuild.yaml", "name": "curl-trigger", "description": "curl trigger", "repository_event_config": { "repository": "REPO_NAME", "repository_type": "GITHUB", // Field filter must be only one of the following: "pullRequest": "PULL_REQUEST_FILTER", "push": "PUSH_FILTER" } } ``` Where: - "REPO_NAME" is the name of the repository connection that you configured in Cloud Build. - "PULL_REQUEST_FILTER" is an instance of [`PullRequestFilter`](https://docs.cloud.google.com/build/docs/api/reference/rest/v1/projects.locations.triggers.md.txt#BuildTrigger.PullRequestFilter), which defines the filter that allows Cloud Build to trigger a build when a matching pull request is made in GitHub. - "PUSH_FILTER" is an instance of [`PushFilter`](https://docs.cloud.google.com/build/docs/api/reference/rest/v1/projects.locations.triggers.md.txt#BuildTrigger.PushFilter), which defines the filter that allows Cloud Build to trigger a build when a matching push is made in GitHub. Enter the following `curl` command in your terminal: curl -X POST -H "Authorization: Bearer "$(gcloud auth print-access-token) -H "Content-Type: application/json; charset=utf-8" -H "x-goog-user-project: PROJECT_NUMBER" https://cloudbuild.googleapis.com/v1/projects/PROJECT_ID/triggers -d @trigger.json Where: - PROJECT_NUMBER is your Google Cloud project number. - PROJECT_ID is your Google Cloud project ID. ## Build and view your changes **To build using GitHub triggers**, you'll need to push and commit changes to your connected source repository or configure your build on pull requests. Once you have checked in your changes, Cloud Build will build your code. **To view your build changes on GitHub** , go to the **Checks** tab in your repository. ![Screenshot of the conversation tab](https://docs.cloud.google.com/build/images/checks-tab.png) You'll see that Cloud Build has built your changes. You'll also see other build details such as the time it took to build your code and the build ID. To view your build changes in Cloud Build, click **View more details on Google Cloud Build** . The **Build details** page in Google Cloud console opens where you can see build information such as status, logs, and build steps. ## Different types of GitHub-based triggers If your source code is in GitHub, Cloud Build provides two ways by which you can automatically execute builds. This section explains the two GitHub-based triggers and compares their features. - **GitHub legacy triggers** : When you create a GitHub legacy trigger, Cloud Build mirrors your GitHub repository in Cloud Source Repositories and uses the mirrored repository for all its operations. You can [create and manage GitHub triggers](https://docs.cloud.google.com/build/docs/automating-builds/create-manage-triggers.md.txt) using the Google Cloud console. > [!NOTE] > **Note:** If you are using GitHub legacy triggers, you will need to grant access to individual organizations with [GitHub](https://github.com/settings/connections/applications/b321194a909cf0837140) to use GitHub legacy triggers. - **GitHub triggers**: This type of trigger uses the Cloud Build GitHub app to configure and authenticate to GitHub. GitHub triggers allow you to automatically start builds on Git pushes and pull requests and view build results on GitHub and the Google Cloud console. You can create and manage GitHub triggers using Google Cloud console or the Cloud Build API, as described on this page. - **GitHub Enterprise triggers** : This type of trigger lets you invoke builds in response to commits or pull requests on a GitHub Enterprise instance. You can [build repositories from GitHub Enterprise](https://docs.cloud.google.com/build/docs/automating-builds/github/build-repos-from-github-enterprise.md.txt) using the Google Cloud console or the Cloud Build API. The following table compares GitHub legacy triggers, GitHub triggers, and GitHub Enterprise triggers: | Feature | GitHub legacy triggers | GitHub triggers | GitHub Enterprise triggers | |---|---|---|---| | Execute builds on pushes to the source code | Yes | Yes | Yes | | Execute builds on pull requests | No | Yes | Yes | | Create trigger using Google Cloud console | Yes | Yes | Yes | | Create trigger using the Cloud Build API | No | Yes | Yes | | Create trigger using the Cloud Build GitHub app | No | Yes | Yes | | View build status on Google Cloud console | Yes | Yes | Yes | | View build status on GitHub | No | Yes | Yes | ## Data sharing The data sent to GitHub from Cloud Build helps you identify triggers by name and see build results on GitHub. The following data is currently shared between Cloud Build and GitHub: - Cloud project ID - Trigger name - Build logs > [!NOTE] > **Note:** Build logs are only shared if you configure your trigger to send build logs. If you created triggers prior to August 2020, data sharing may not be enabled for your project. You can enable data sharing for all GitHub triggers in your project by clicking **Enable** on the [Cloud Build Data sharing tab](https://console.cloud.google.com/cloud-build/settings/data-sharing). If you have [required status checks](https://docs.github.com/en/github/administering-a-repository/enabling-required-status-checks) enabled for a GitHub repository, enabling data sharing may temporarily break status checks. You can adjust status check configurations to look for your trigger name by: - Disabling any Cloud Build-specific required checks on the GitHub repository - Ensuring that data sharing is enabled in Cloud Build - Executing a new build in Cloud Build that posts statuses to your repository - Re-enabling required status checks, selecting trigger name > [!NOTE] > **Note:** Enabling data sharing for a project is not reversible. ## What's next - Learn how to [create and manage build triggers](https://docs.cloud.google.com/build/docs/automating-builds/create-manage-triggers.md.txt). - Learn how to [perform blue-green deployments on Compute Engine](https://docs.cloud.google.com/build/docs/deploying-builds/deploy-compute-engine.md.txt).