Firebase deploy trigger functions with dotenv not working

[REQUIRED] Environment info

firebase-tools: 11.0.1

Platform: macOS

[REQUIRED] Test case

I have added a .env file providing some variables:

STORAGE_UPLOAD_BUCKET=mycustombucket

Then i want to use this variable to create a trigger:

functions.storage
  .bucket(process.env.STORAGE_UPLOAD_BUCKET)
  .object()
  .onFinalize(async (object) => {
  console.log(process.env.STORAGE_UPLOAD_BUCKET);
  //DO STUFF...
});

The problem is that STORAGE_UPLOAD_BUCKET is not defined during the time of deployment, so the trigger gets deployed for the default bucket, not matter the value of STORAGE_UPLOAD_BUCKET. But during runtime of the function it is then set. The same problem exists for other triggers: You cannot use environment variables in firestore trigger paths.

[inlined]

We didn’t remove Runtime Config from the discovery phase for reverse compatibility reasons, though it is going away in general (no ETA yet). We don’t populate dotenv files during the discovery phase because our reconciliation between Functions and Extensions requires us to be able to determine the shape of the deployment generically outside the context of the project/environment variables. We’ll do this by capturing dependencies on, for example, the storage bucket as a “parameter”. This parameter will be enforced at deploy time (e.g. while interactive you’ll be prompted for any missing values and in non-interactive mode a deployment will fail). It will be backed by dotenv files in Cloud Functions for Firebase and by the backend server in the case of Firebase Extensions.

[inlined]

Yes, I would recommend checking the status of an environment variable before doing global initialization. So instead of:

const dbCon = new Database(process.env.DB_ADDRESS);

change to

let dbConn;
if (process.env.DB_ADDRESS) {
  dbConn = new Database(process.env.DB_ADDRESS);
}

We are considering giving a startup callback as well so you can have code that runs only when a new instance is launched in production.