OTP migrations fail to connect to Postgres with SSL

Environment

• Installation type (OTP or From Source): OTP
• Pleroma version (could be found in the "Version" tab of settings in Pleroma-FE): 2.0.50-2385-g47698fc3-develop
• Elixir version (elixir -v for from source installations, N/A for OTP): N/A
• Operating system: Alpine (in Docker), macOS
• PostgreSQL version (psql -V): 11

Bug description

Running Pleroma migrations fails with the following when connecting via SSL:

** (EXIT from #PID<0.164.0>) an exception was raised:
    ** (RuntimeError) SSL connection can not be established because `:ssl` application is not started,
you can add it to `extra_application` in your `mix.exs`:

  def application do
    [extra_applications: [:ssl]]
  end

        (postgrex 0.15.5) lib/postgrex.ex:554: Postgrex.ensure_deps_started!/1
        (postgrex 0.15.5) lib/postgrex.ex:496: Postgrex.child_spec/1
        (ecto_sql 3.4.5) lib/ecto/adapters/sql.ex:459: Ecto.Adapters.SQL.init/3
        (ecto 3.4.5) lib/ecto/repo/supervisor.ex:178: Ecto.Repo.Supervisor.init/1
        (stdlib 3.12.1) supervisor.erl:295: :supervisor.init/1
        (stdlib 3.12.1) gen_server.erl:374: :gen_server.init_it/2
        (stdlib 3.12.1) gen_server.erl:342: :gen_server.init_it/6
        (stdlib 3.12.1) proc_lib.erl:249: :proc_lib.init_p_do_apply/3

There's a related issue and PR against Postgrex.

To replicate:

1. Run Postgres with SSL
2. Build a new release via MIX_ENV=prod mix release
3. Set ssl: true in prod.secret.exs
4. Run ./bin/pleroma_ctl migrate. This should fail with the error above.

It looks like a reasonable patch for this is adding:

Application.ensure_all_started(:ssl)

to lib/mix/tasks/pleroma/ecto/migrate.ex.

The above snippet has fixed it in my case, so I'll raise a PR shortly. Raised: !2894 (merged)

I'm still a little confused why having :ssl in mix.exs in extra_applications doesn't fix this to begin with..