Do Ecto migration from a release of an elixir app

Question

I've made a release of my elixir application.
It starts to run a supervised task using DB when the app is lunched.

When the DB is not migrated, the task keep error and app is terminated.

I read http://blog.firstiwaslike.com/elixir-deployments-with-distillery-running-ecto-migrations/, https://hexdocs.pm/distillery/running-migrations.html, and tried to implement migration function following them, but failed because the app needs to be started to load config of the app and it make the command terminated.

When I run Application.get_all_env(:my_app) without start my app, it returns empty list []. Is there anyway to run Ecto.Migrator.run(MyApp.Repo, path, :up, all: true) without start the app?

Answer 1

It is enough to load the application with Application.load(:my_app) to have access to the env - it doesn't need to be started.

A detailed guide on running migrations with releases is available in the distillery documentation.