Set galaxy settings (mongo_url) at startup, without settings file

Does anyone have a way of deploying to Galaxy without using a settings.json file? I can’t make Galaxy deploy my meteor app by overriding the Meteor.settings at boot without a settings file. All I get are dreaded Error: MONGO_URL must be set in environment errors.

I want to set the MONGO_URL env var at meteor startup by retrieving them from a secret store (e.g. AWS Secrets Manager).

Is there a way to delay Meteor Mongo connection attempts when Meteor is booting, and trigger the mongo connection once the meteor entry point is hit?

How do you deal with production secrets? I’m not really interested in solutions involving bash scripts or similar package.json deploy scripts.

Thank you.

We use Doppler ( with a node.js build script which gets run by our bitbucket pipelines on deploy. It constructs the settings file on deployment