Carrot

AMQP connection manager

Installation

The package can be installed by adding carrot to your list of dependencies in mix.exs:

def deps do
  [{:carrot, "~> 1.0"}]
end

Configuration and startup

Carrot does not use Mix or Application configuration. The ConnectionManager simply takes a Keyword list of connection options as the first argument to start_link/2:

{:ok, pid} = Carrot.ConnectionManager.start_link([
  host: "localhost",
  password: "guest",
  username: "guest",
  virtual_host: "/"
])

Supervision

The ConnectionManager is meant to be started as part of a supervision tree. Therefore, it is most common to register the process with a name. The second argument to start_link/2 is a list of GenServer options.

See Name Registration for more details.

...
worker(Carrot.ConnectionManager, [
  [
    host: "localhost",
    password: "guest",
    username: "guest",
    virtual_host: "/"
  ],
  [
    name: Carrot.ConnectionManager
  ]
]),
...

Potential gotchas

If your application dependends on cowboy at v1.x, you may need to add a dependency override for ranch:

{:ranch, "~> 1.4", override: true}

It appears there are no breaking changes between ranch 1.3 and 1.5.

Another issue you might come across is from a dependency on lager. You may need to ensure that lager is started before Elixir's logger:

# mix.exs
def application do
  [applications: [:lager, :logger]]
end

You can also silence lager by setting its log level to critical:

config :lager,
  handlers: [level: :critical]

Documentation