Hi all, I have a Elixir Umbrella with a Phoenix Web app that I am attempting to deploy to Heroku using Docker.

The Docker build and release succeeds; however, whenever I attempt to visit the running application I get the following error:

2019-01-16T18:11:28.595542+00:00 heroku[web.1]: Error R10 (Boot timeout) -> Web process failed to bind to $PORT within 60 seconds of launch

2019-01-16T18:11:28.595632+00:00 heroku[web.1]: Stopping process with SIGKILL

2019-01-16T18:11:28.685658+00:00 heroku[web.1]: Process exited with status 137

I am using Phoenix 1.4. I tried a few fixes, namely setting the http config variable correctly. My Phoenix configuration is as follows:

config :bazaar, BazaarWeb.Endpoint,
    load_from_system_env: true,
    http: [port: {:system, "PORT"}],
    url: [host: {:system, "HOST"}, port: 80],
    cache_static_manifest: "priv/static/cache_manifest.json"

The host environment variable is properly set inside the Heroku configuration. I’m not sure what else to try.