erlang OTP app using rebar, dev environment

Question

I am in the process or learning erlang OTP and rebar and I have put together a small example app using a couple of dependencies: cowboy and lager.

I have issued

rebar get-deps
rebar compile

And things went smoothly. Now I want to fire up my console to test things around but it is not obvious to me how to start the dependency applications.

I tried issuing a

rebar generate 

In order to get all the orchestration of firing up the apps, even though it's overkill for just development tests, but I miserably failed getting the following dump

Crash dump was written to: erl_crash.dump
eheap_alloc: Cannot allocate 1459620480 bytes of memory (of type "old_heap").
Aborted

The ebin dir only has beam files for the app I wrote but not the dependencies, I see the dependencies have their own ebin directory inside the main app deps directory, how would I go about having them available in a console to start them up?

I would appreciate if someone can shed some light as to what the common practice is for the dev env with multiple OTP apps.

I have read a couple of tutorials but they are mostly targeted at the rebar release cycle and not the development process.

TIA

Answer 1

In your case, the modules you pull into the deps directory should typically be called from within your application code - and your application can be typically invoked from the Erlang shell using the application:start/1 function. If you haven't yet, I strongly suggest that you read Chapter 12, "OTP Behaviors", of Francesco Cesarini's excellent book Erlang Programming - it's a great practical introduction for what you're attempting.