Running a Phoenix application release with exrm crashes

Question

I am trying to create a release of a stock Phoenix application (based on Elixir and Erlang) using exrm.

The first release for the dev mix environment is created fine, but crashes when run using ./rel/my_app/bin/my_app console. This happens running Ubuntu 14.04 inside a Vagrant/Virtual Box virtual machine.

On my Mac, the same setup runs fine. Unfortunately, I need to build the release on a machine with the same architecture as the target server, which will run Ubuntu.

You can find the application here: https://github.com/mavenastic/my_app. It includes the steps taken to install dependencies and create the project on the VM (see STEPS.md) as well as a Erlang crash dump.

Here is the error I get from attempting to run the console:

{"Kernel pid terminated",application_controller,"{application_start_failure,my_app,{{shutdown,{failed_to_start_child,'Elixir.MyApp.Endpoint',{shutdown,{failed_to_start_child,'Elixir.Phoenix.CodeReloader.Server',{undef,[{'Elixir.Mix.Project',config,[],[]},{'Elixir.Phoenix.CodeReloader.Server',init,1,[{file,\"lib/phoenix/code_reloader/server.ex\"},{line,29}]},{gen_server,init_it,6,[{file,\"gen_server.erl\"},{line,328}]},{proc_lib,init_p_do_apply,3,[{file,\"proc_lib.erl\"},{line,240}]}]}}}}},{'Elixir.MyApp',start,[normal,[]]}}}"}

EDIT:

I tried to create a release for the production environment as well with MIX_ENV=prod mix release. The release is successfully generated and MIX_ENV=prod PORT=8889 ./rel/my_app/bin/my_app console runs fine. However, I cannot ping the server nor run a remote console once it starts, so it seems something is still missing for the application to run properly.

$ MIX_ENV=prod PORT=8889 ./rel/my_app/bin/my_app start
$ MIX_ENV=prod PORT=8889 ./rel/my_app/bin/my_app ping

=INFO REPORT==== 24-Oct-2015::10:28:25 ===
Protocol: "inet_tcp": register/listen error: econnrefused
escript: exception error: no match of right hand side value
                 {error,
                     {{shutdown,
                          {failed_to_start_child,net_kernel,
                              {'EXIT',nodistribution}}},
                      {child,undefined,net_sup_dynamic,
                          {erl_distribution,start_link,
                              [['[email protected]',longnames]]},
                          permanent,1000,supervisor,
                          [erl_distribution]}}}

$ ps aux | grep my_app
vagrant   2572  0.0  0.0   7532    96 ?        S    10:28   0:00 /vagrant/my_app/rel/my_app/erts-7.1/bin/epmd -daemon
vagrant   2575  0.0  0.2   9448  2256 pts/0    S+   10:28   0:00 grep --color=auto my_app

$ MIX_ENV=prod PORT=8889 ./rel/my_app/bin/my_app remote_console
$

Also, from what I gathered, I should be able to create a release for the dev or any other environment as well. So the missing piece might affect both environments.

Thanks in advance!

Answer 1

To me it looks like the problem is that you're creating the release in your dev environment (instead of the prod env).

This part:

{undef,[{'Elixir.Mix.Project',config,[],[]}

of the (terribly and awesomely à la Erlang) error message basically says that Mix.Project.config/0 is undefined. Mix is not included in releases but I'm guessing Phoenix uses it in its code reloader, which you usually don't run in production.

Try generating the release with MIX_ENV=prod and see if it works.