Let Phoenix Framework run over the Elli server through Pastelli plug adapter and elli_websocket.

As of Phoenix at version greater or equal than 1.1.0, the framework allows for third party plug adapters to be fitted inside the application supervision tree. This project implements Phoenix.Endpoint.Handler behaviour for Pastelli.

See this in Action in a fork of the default phoenix chat example.

Add :pastelli_phoenix to your phoenix app dependencies

def deps do
  [
    {:phoenix, "~> 1.4.0"},
    {:pastelli_phoenix, "~> 0.1.0", github: "zampino/pastelli_phoenix" },
    # ...
  ]
end

in config.exs or [env].exs

config :my_app, MyApp.Endpoint,
  handler: Pastelli.Phoenix,
  http: [
    port: {:system, "PORT"},
    # ...
  ]

like in here.

In your application endpoint use Pastelli.Phoenix.Endpoint module before the usual Phoenix.Endpoint.

A new plug module will be defined at compile time with the alias Pastelli.Phoenix.SocketDispatchRouter. This is to be plugged (anywhere you like but before MyApp.Router of course) and will convert phoenix sockets from cowboy-dispatch rules into Pastelli standard route dispatches. Pastelli will hand ws-upgrade connections over to elli_websocket.

Just like this:

defmodule MyApp.Endpoint do
  use Pastelli.Phoenix.Endpoint
  use Phoenix.Endpoint, otp_app: :chat

  plug Pastelli.Phoenix.SocketDispatchRouter

  socket "/socket", MyApp.UserSocket

  plug Plug.Static,
    at: "/", from: :my_app,
    only: ~w(css images js favicon.ico robots.txt)

  if code_reloading? do
    socket "/phoenix/live_reload/socket", Phoenix.LiveReloader.Socket
    plug Phoenix.CodeReloader
    plug Phoenix.LiveReloader
  end

  # ... and the usual plug pipeline

  plug MyApp.Router
end