Fly.io: The app is not listening on the expected address and will not be reachable by fly-proxy

Phoenix Forum Questions / Help
1

I’m trying to deploy an existing Phoenix app to fly.io. After a few tries it seems to work, but now I get the “The app is not listening on the expected address and will not be reachable by fly-proxy.” error.

The log then proceeds to print this:

Found these processes inside the machine with open listening sockets:
  PROCESS

                                                          | ADDRESSES
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------------------------------------------
----------------------------------------------------------*---------------------------------------
  /app/erts-13.1.3/bin/beam.smp -- -root /app -bindir /app/erts-13.1.3/bin -progname erl -- -home /nonexistent -- -proto_dist inet6_tcp -- -noshell -s elixir sta
rt_cli -mode embedded -setcookie PWOVL6U2DQUEE7V7BNYSLJPK2XG7CYEZPH6MS4Y2QJQDIW6R7E4A==== -sname magpie -config /app/releases/2.3.4/sys -boot /app/releases/2.3.4
/start -boot_var RELEASE_LIB /app/lib -- -extra --no-halt | [::]:33127
  /.fly/hallpass

                                                          | [fdaa:2:6f01:a7b:141:65dd:fe42:2]:22
  /app/erts-13.1.3/bin/epmd -daemon

                                                          | 0.0.0.0:4369, [::]:4369

Curiously, the first item in the list seems to be my app? I have no idea why it’s listening on 33127 though.

I tried to run fly deploy again, and now it’s on 40627.

Is this the app process, or is this something irrelevant?

I checked my runtime.exs, prod.exs and config.exs against a vanilla new project, which I was able to deploy successfully, and I seem to find no difference in terms of the port configuration… (I still don’t know where the “8080” is supposed to come from in the first place though.)

2

OK I finally saw this line from the logs:

Configuration :server was not enabled for Magpie.Endpoint, http/https services won't start

I have no idea why this is the case, since my rel/overlays/bin/server has exactly the same content as the vanilla test app:

#!/bin/sh
cd -P -- "$(dirname -- "$0")"
PHX_SERVER=true exec ./magpie start

But anyways I removed the conditional part on

if System.get_env("PHX_SERVER") do
  config :magpie, MagpieWeb.Endpoint, server: true
end

in my runtime.exs and it finally worked.