Last active
July 12, 2017 23:28
-
-
Save merqlove/625040c543b7badcedbea4e4a4c9e55d to your computer and use it in GitHub Desktop.
Elixir AMQP resilent publisher
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
defmodule Publisher do | |
use GenServer | |
use AMQP | |
require Logger | |
@amqp [host: "localhost", port: "5682"] | |
@reconnect_timeout 5000 | |
def start_link() do | |
GenServer.start_link(__MODULE__, [], name: :publisher_server) | |
end | |
def init(_) do | |
state = %{connected: false, channel: nil, queue_name: "task_queue", conn: nil)} | |
{:ok, rabbitmq_connect(state)} | |
end | |
@doc """ | |
lookup interface | |
""" | |
def lookup, do: GenServer.call(:publisher_server, {:lookup}) | |
@doc """ | |
publish interface | |
""" | |
def publish(message) when is_bitstring(message) do | |
GenServer.call(:publisher_server, {:publish, message}) | |
end | |
def publish(_), do: :error | |
def handle_call({:lookup}, _, state), do: {:reply, state, state} | |
def handle_call({:publish, message}, _, %{channel: chan, connected: true, queue_name: queue_name} = state) do | |
result = Basic.publish(chan, "", queue_name, message, persistent: true) | |
{:reply, result, state} | |
end | |
@doc """ | |
handles process EXIT | |
""" | |
def handle_info({:DOWN, _, :process, _pid, _reason}, state) do | |
new_state = rabbitmq_connect(state) | |
{:noreply, state} | |
end | |
@doc """ | |
handles rabbit reconnect | |
""" | |
def handle_info(:rabbitmq_connect, state) do | |
new_state = rabbitmq_connect(state) | |
{:noreply, state} | |
end | |
@doc """ | |
handles other messages | |
""" | |
def handle_info(msg, state) do | |
Logger.warn("Unknown msg received #{inspect(msg)}") | |
{:noreply, state} | |
end | |
@doc """ | |
handles server down | |
""" | |
def terminate(_reason, %{conn: conn}) do | |
Connection.close(conn) | |
:ok | |
end | |
defp rabbitmq_connect(%{queue_name: queue_name} = state) do | |
default_opts = [host: nil, port: nil] | |
opts = | |
@amqp | |
|> Enum.filter(fn({_, v}) -> v != "" && v != nil end) | |
case Connection.open(Keyword.merge(default_opts, opts)) do | |
{:ok, conn} -> | |
Process.monitor(conn.pid) | |
{:ok, chan} = Channel.open(conn) | |
Queue.declare(chan, queue_name, durable: true) | |
%{ state | channel: chan, connected: true, conn: conn } | |
{:error, _} -> | |
# Reconnection loop | |
reconnect(state) | |
%{state | channel: nil, connected: false, conn: nil } | |
end | |
end | |
defp reconnect(state) do | |
Process.send_after(self(), :rabbitmq_connect, @reconnect_timeout) | |
end | |
end |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment