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In this sprint, we’ll explore Google Cloud Build—its core capabilities—and automate Docker image builds from GitHub into Google Artifact Registry. By the end, you will:
  • Grasp Cloud Build features and benefits
  • Link a GitHub repo to Cloud Build via triggers
  • Automate Docker image builds on merges and push them to Artifact Registry

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1. Key Features of Cloud Build

Before writing any pipelines, it’s crucial to understand what Cloud Build offers. Search the official Cloud Build Documentation or the Cloud Console for more details.
The image shows a search bar with the query "What are the features of Cloud Build?"
FeatureDescription
Flexible Build ConfigurationsDefine builds in YAML or JSON
Native Artifact Registry IntegrationPush and pull images directly to Artifact Registry
Multiple Source Repository SupportConnect Cloud Source Repos, GitHub, Bitbucket
Parallel Steps & CachingSpeed up builds with parallelism and cache layers
Cloud Build can also integrate with Pub/Sub, Cloud Functions, and other GCP services for advanced workflows.

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2. Set Up a GitHub Trigger

Linking Cloud Build to your GitHub repository allows automated builds on code changes. Follow these steps:
  1. Enable the Cloud Build API
    In your GCP project, navigate to APIs & Services » Library and enable Cloud Build API.
  2. Create a Build Trigger
    • Go to Cloud Build » Triggers in the Cloud Console.
    • Click Create trigger and choose GitHub as the source.
  3. Authorize & Select Repository
    Grant Cloud Build access to your GitHub account and pick the target repository.
  4. Configure Trigger Events
    • Trigger on push to the main branch.
    • Optionally, fire on pull-request merges.
Ensure your GitHub App has the correct scopes (repo, admin:repo_hook) to create webhooks and read repository data.

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3. Define cloudbuild.yaml to Build & Push Docker Images

With your trigger in place, add a cloudbuild.yaml at the root of your repo. This file defines steps to build a Docker image and push it into Artifact Registry.
The image illustrates a process flow from automating Docker image builds to storing them in the GCP Artifact Registry.
steps:
  - name: 'gcr.io/cloud-builders/docker'
    args:
      - build
      - -t
      - 'us-central1-docker.pkg.dev/my-project/my-repo/my-app:$SHORT_SHA'
      - .
  - name: 'gcr.io/cloud-builders/docker'
    args:
      - push
      - 'us-central1-docker.pkg.dev/my-project/my-repo/my-app:$SHORT_SHA'
images:
  - 'us-central1-docker.pkg.dev/my-project/my-repo/my-app:$SHORT_SHA'
What happens during execution:
  1. Build: Docker builds an image tagged with the commit’s short SHA.
  2. Push: The image is uploaded to Artifact Registry.
  3. Images: Cloud Build tracks uploaded images for logging and metadata.
Use variables like $SHORT_SHA, $BRANCH_NAME, or custom substitutions to tag images dynamically.

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Sprint 04 Goals Recap

The image lists sprint goals related to Cloud Build, including understanding it in detail, connecting it to a GitHub repository, and automating the Docker image build process.
  1. Detailed understanding of Cloud Build features
  2. GitHub repository integration via build triggers
  3. Automated Docker image builds and storage in Artifact Registry
Congratulations—you’ve automated your CI/CD pipeline for Docker images! See you in the next sprint.

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