Share (parameterized) cloudbuild.yaml between multiple GitHub projects?

Question

I've managed to trigger a Google Cloud Build on every commit to GitHub successfully. However, we have many different source code repositories (projects) on GitHub, that all use Maven and Spring Boot, and I would like all of these projects to use the same cloudbuild.yaml (or a shared template). This way we don't need to duplicate the cloudbuild.yaml in all projects (it'll be essentially the same in most projects).

For example, let's just take two different projects on GitHub, A and B. Their cloudbuild.yaml files could look something like this (but much more complex in our actual projects):

Project A:

steps:
  - name: maven:3.8.6-eclipse-temurin-17-alpine
    entrypoint: mvn
    args: [ 'test' ]
  - name: maven:3.8.6-eclipse-temurin-17-alpine
    entrypoint: mvn
    args: [ 'package', '-Dmaven.test.skip=true' ]
  - name: gcr.io/cloud-builders/docker
    args: [ "build", "-t", "europe-west1-docker.pkg.dev/projectname/repo/project-a", "--build-arg=JAR_FILE=target/project-a.jar", "." ]
images: [ "europe-west1-docker.pkg.dev/projectname/repo/project-a" ]

Project B:

steps:
  - name: maven:3.8.6-eclipse-temurin-17-alpine
    entrypoint: mvn
    args: [ 'test' ]
  - name: maven:3.8.6-eclipse-temurin-17-alpine
    entrypoint: mvn
    args: [ 'package', '-Dmaven.test.skip=true' ]
  - name: gcr.io/cloud-builders/docker
    args: [ "build", "-t", "europe-west1-docker.pkg.dev/projectname/repo/project-a", "--build-arg=JAR_FILE=target/project-b.jar", "." ]
images: [ "europe-west1-docker.pkg.dev/projectname/repo/project-b" ]

The only thing that is different is the jar file and image name, the steps are the same. Now imagine having hundreds of such projects, it can become a maintenance nightmare if we need to change or add a build step for each project.

A better approach, in my mind, would be to have a template file that could be shared:

steps:
  - name: maven:3.8.6-eclipse-temurin-17-alpine
    entrypoint: mvn
    args: [ 'test' ]
  - name: maven:3.8.6-eclipse-temurin-17-alpine
    entrypoint: mvn
    args: [ 'package', '-Dmaven.test.skip=true' ]
  - name: gcr.io/cloud-builders/docker
    args: [ "build", "-t", "europe-west1-docker.pkg.dev/projectname/repo/${PROJECT_NAME}", "--build-arg=JAR_FILE=target/${PROJECT_NAME}.jar", "." ]
images: [ "europe-west1-docker.pkg.dev/projectname/repo/${PROJECT_NAME}" ]

It would then be great if such a template file could be uploaded to GCS and then reused in the cloudbuild.yaml file in each project:

Project A:

steps:
  import:
    gcs: gs:/my-build-bucket/cloudbuild-template.yaml
    parameters: 
      PROJECT_NAME: project-a

Project B:

steps:
  import:
    gcs: gs:/my-build-bucket/cloudbuild-template.yaml
    parameters: 
      PROJECT_NAME: project-b

Does such a thing exists for Google Cloud Build? How do you import/reuse build steps in different builds as I described above? What's the recommended way to achieve this?

Answer 1

I contacted Google Cloud support and they told me that this is not currently available. They are aware of the issue and it's something that they're working on (no eta on when it's going to be available).

Their recommendation, in the meantime, is to use Tekton .