Build Docker Images using Google Cloud Build from Your GitHub Repository

Triggering a Docker image build on Google Cloud Build when pushing commits to a GitHub repository.

Create Google Cloud Build Configuration File

Create a cloudbuild.yaml in the root folder:

steps:
- id: my-blog-cache-image
  name: gcr.io/cloud-builders/docker
  entrypoint: "/bin/bash"
  args:
   - "-c"
   - |
     docker pull gcr.io/$PROJECT_ID/my-blog:$BRANCH_NAME || exit 0
  waitFor: ["-"]
- id: my-blog-build-image
  name: gcr.io/cloud-builders/docker
  args: [
    "build",
    "-t", "gcr.io/$PROJECT_ID/my-blog:$BRANCH_NAME",
    "-t", "gcr.io/$PROJECT_ID/my-blog:$SHORT_SHA",
    "docker/my-blog/",
  ]
  waitFor: ["my-blog-cache-image"]
images:
- gcr.io/$PROJECT_ID/my-blog:$SHORT_SHA

If you want to push images to another region, simply rename gcr.io to something like asia.gcr.io.

ref:
https://cloud.google.com/build/docs/configuring-builds/create-basic-configuration
https://cloud.google.com/cloud-build/docs/configuring-builds/store-images-artifacts

Configure Google Cloud Build with Your GitHub Repository

Go to Google Cloud Dashboard > Google Cloud Build > Triggers > Create trigger

• Region: Global
• Event: Push to a branch
• Source: 1st Gen
• Repository:
  • Connect new repository
  • Source code management provider: GitHub (Cloud Build GitHub App)
  • Install Google Cloud Build GitHub app
  • Only select repositories
• Branch: ^main$
• Type: Autodetected
• Location: Repository

That's it, now you could push some commits to your GitHub repository.

ref:
https://console.cloud.google.com/cloud-build/triggers
https://console.cloud.google.com/cloud-build/builds