Triggering a Google Container Builder build via Cloud Functions

Question

I am using Container Builder to process huge JSON files and transform them. It's a nice possibility of a non-standard usage of it as described here.

Is it possible to trigger a container builder build and pass a parameter to it via cloud functions? This would allow to act on newly uploaded files in GCS and process them via container builder automatically.

Currently I am trying to use the REST API for triggering it (I am new to Node.js), but I get a 404 on my URL. I am developing on a Cloud Shell instance with full API access.

The URL that I am trying to trigger via a PUT request and a JSON body containing the JSON equivalent of a successfully ran cloudbuild.yaml is: https://cloudbuild.googleapis.com/v1/projects/[PROJECT_ID]/builds

I am using the requests library from Node.js:

request({ url: "https://cloudbuild.googleapis.com/v1/projects/[PROJECT_ID]/builds", 
    method: 'PUT', 
    json: {"steps":[{"name":"gcr.io/cloud-builders/gsutil",(...),
    function(error, response, body){
        console.log(error)
        console.log(response)
        console.log(body)
    })

Answer 1

Apparently, there is already someone who has done it. The library is on GitHub: https://github.com/mhr3/gcp-container-builder-node and available via npm: https://www.npmjs.com/package/gcp-container-builder

The usage was not clear to me at first, but this is how I am using it now:

var build = Object.create(null);
build.steps = [{
    name: 'gcr.io/cloud-builders/gsutil',
    args: ['cp', 'gs://some_bucket/some_file.json', '/workspace/some_file.json']
}]

// more build steps, converting the file, uploading it, etc.

builder.createBuild(build, function(err, resp) {
    console.log(err);
    console.log(resp);
});