Before we connect to the node, we have to expose the container ports that will be used to connect the nodes. Edit your docker-compose.dev.yml file and add the following:
$ cat docker-compose.dev.yml # ... app: image: elixir_drip:dev # ... ports: - 4000:4000
- 4369 - 9001-9004 # ...
The 9001-9004 port range is the range on which EPMD will assign ports to new nodes. We will tell EPMD to respect this range by passing the inet_dist_listen_min and inet_dist_listen_max parameters when running Elixir, and also when starting the application release. To pass these parameters when running the release, we need to set the erl_opts option in the release configuration:
$ cat rel/config.exs # ...environment :prod ...
