Separating Workers From Apps?

Phoenix Forum Questions / Help
21

You’re right, I definitely haven’t internalised Elixir is expression based. I’m barely 4 days in. I’m sure I’ll get there.

Thanks for the explanation, I’ll keep reading/learning.

I would be interested to see an example of how I would express those two states of children. Perhaps using children = case unquote(Mix.env()) do... as above?

children = if System.get_env("APP_WORKER") do
  [
    supervisor(Verk.Supervisor, [])
  ]
  else
  [
    supervisor(Pink.Repo, []),
    supervisor(PinkWeb.Endpoint, []),
    worker(Redix,
      [Confex.get_env(:verk, :redis_url), [name: Verk.Redis]], id: Verk.Redis
    )
  ]
end
22

Conceptually from the code you’ve shown your intent seems to be

{children, redis_url} = if app_worker?() do
  ...
  {app_worker_children, nil} # i.e. is it actually nil or is it already a some default value?
else
  ...
  {other_children, other_redis_url}
end
23

Maybe. But I don’t need two return values, and I don’t need access to redis_url outside of the expression. That was mainly just a helper to clean up the worker definition pulled from Verk codebase. Though I reckon moving that, along with the APP_WORKER ENV variable fetch into their own functions would be cleaner.

Appreciate the suggestions. This is my first foray into a functional language.

24

mix run starts the application, in case you don’t really need phx.server for workers.

1 Like
25

Just a note: mix run would only work if mix is available.

So on a “production” machine (with or without docker) I would recommend using bitwalker/distillery.
It makes creating otp releases rather easy and possible to run them without any need for mix.

2 Likes
26

Thanks for the pointers guys. Was planning to use distillery for production.