Downfalls of a bash based approach: You need to maintain it. And bash is hard to debug, especially when the house is on fire (production outage, etc)

Integrating should be quite straigthforward. Install Tanka, create a new project (tk init), copy your source of truth YAML (without transformations) somewhere under lib/ (for example lib/foo).

Then go to lib/foo/foo, and import each of those yaml files:

   {
     foo: {
       deployment: import "./deployment.yaml",
       service: import "./service.yaml",
     }
   }

In environments/default/main.jsonnet:

  (import "foo/foo.jsonnet") + {
    // patch environment specific things here
    // https://tanka.dev/tutorial/environments#patching
  }

Then use `tk show` to verify it works.

Furthermore, follow the tutorial to get an in depth understanding of Tanka: https://tanka.dev/tutorial/overview