How to use multi project multi environment deployment using google deployment manager and google cloud build

Question

Currently we're having a dev environment in a gcp project. We're using GDM templates and other stuffs along with repo in bitbucket. Whenever we push any changes in bitbucket it builds and deploy to this dev environment. Suddenly, we've decided to have a new gcp project as test environment and we want to deploy automatically to this environment like dev environment. Our preference will be to deploy to this environment from the cloudbuild execution in dev environment. Can you suggest us any guideline that'll help us to set up things in one place that'll automatically deploy this in multiple projects as multiple environments automatically?

Answer 1

You need separate calls for separate projects. Just like almost all Google API resources deploymentmanager/deployments lives inside a project (https://www.googleapis.com/deploymentmanager/v2/projects/[PROJECT]/global/deployments), thus you cannot deploy to multiple projects in one call.

Answer 2

You can use Terraform to achieve this.
There's a lot of information on how to start here.
However, I would suggest having projects in separate deployments. This way you limit the blast radius and protect production from errors occurring in other environments.