Merge pull request #21 from esl/improve-consumer-example

[change] move consumer execution script into the Readme

README.md

@@ -34,7 +34,7 @@ end
 
 *  when a client checks out a channel out of the pool the connection worker monitors that client to return the channel into it in case of a crash
 
-*  in case you don't want to pool channels, you can disable this feature 
+*  in case you don't want to pool channels, you can disable this feature
 by setting the `channels` number to 0, then you can create channels on demand
 
 ## High Level Architecture
@@ -58,6 +58,24 @@ Also:
     * Monitor clients accessing channels,
     * Queue and dequeue channels from the pool in order to make them accessible to one client at a time reducing the potential for race conditions.
 
+## Setup RabbitMQ with docker
+
+```bash
+# pull RabbitMQ image from docker
+$> docker pull rabbitmq:3.7.7-management
+# run docker in background
+# name the container
+# remove container if already exists
+# attach default port between the container and your laptop
+# attach default management port between the container and your laptop
+# start rabbitmq with management console
+$> docker run --detach --rm --hostname bugs-bunny --name roger_rabbit -p 5672:5672 -p 15672:15672 rabbitmq:3.7.7-management
+# if you need to stop the container
+$> docker stop roger_rabbit
+# if you need to remove the container manually
+$> docker container rm roger_rabbit
+```
+
 ## Supervision hierarchy
 
 ![supervisor diagram](https://user-images.githubusercontent.com/1157892/52127565-681b8400-2600-11e9-8c37-34287e4c9b2c.png)
@@ -118,7 +136,7 @@ queue no longer exist).
 
 Images are taken from [RabbitMQ Tutorials](https://www.rabbitmq.com/tutorials/tutorial-four-python.html)
 
-### Setting up a direct exchange with bindings
+## Setting up a direct exchange with bindings
 
 ![Direct Exchange Multiple](https://www.rabbitmq.com/img/tutorials/direct-exchange.png)
 
@@ -164,7 +182,7 @@ ExRabbitPool.PoolSupervisor.start_link(
 ExRabbitPool.Worker.SetupQueue.start_link({pool_id, queues_config})
 ```
 
-### Setting up a direct exchange with multiple bindings
+## Setting up a direct exchange with multiple bindings
 
 ![Direct Exchange Multiple](https://www.rabbitmq.com/img/tutorials/direct-exchange-multiple.png)
 
@@ -202,3 +220,46 @@ ExRabbitPool.PoolSupervisor.start_link(
 
 ExRabbitPool.Worker.SetupQueue.start_link({pool_id, queues_config})
 ```
+
+## EchoConsumer - Example
+
+In the `examples` directory you are going to find an implementation of a RabbitMQ
+consumer using the library, all you need to do is, starting RabbitMQ
+[with docker](#setup-rabbitmq-with-docker), and copy/paste the following code into the `iex` console.
+What it does is, setup the connection pool, setup the queues, exchanges and
+bindings to use, start the consumer and finally publish some messages to the
+exchange so the consumer can echo it.
+
+```elixir
+rabbitmq_config = [channels: 2]
+
+rabbitmq_conn_pool = [
+  name: {:local, :connection_pool},
+  worker_module: ExRabbitPool.Worker.RabbitConnection,
+  size: 1,
+  max_overflow: 0
+]
+
+{:ok, pid} =
+  ExRabbitPool.PoolSupervisor.start_link(
+    rabbitmq_config: rabbitmq_config,
+    connection_pools: [rabbitmq_conn_pool]
+  )
+
+queue = "ex_rabbit_pool"
+exchange = "my_exchange"
+routing_key = "example"
+
+ExRabbitPool.with_channel(:connection_pool, fn {:ok, channel} ->
+  {:ok, _} = AMQP.Queue.declare(channel, queue, auto_delete: true, exclusive: true)
+  :ok = AMQP.Exchange.declare(channel, exchange, :direct, auto_delete: true, exclusive: true)
+  :ok = AMQP.Queue.bind(channel, queue, exchange, routing_key: routing_key)
+end)
+
+{:ok, consumer_pid} = Example.EchoConsumer.start_link(pool_id: :connection_pool, queue: queue)
+
+ExRabbitPool.with_channel(:connection_pool, fn {:ok, channel} ->
+  :ok = AMQP.Basic.publish(channel, exchange, routing_key, "Hello World!")
+  :ok = AMQP.Basic.publish(channel, exchange, routing_key, "Hell Yeah!")
+end)
+```

examples/echo_consumer.ex

@@ -34,35 +34,3 @@ defmodule Example.EchoConsumer do
     :ok
   end
 end
-
-rabbitmq_config = [channels: 2]
-
-rabbitmq_conn_pool = [
-  name: {:local, :connection_pool},
-  worker_module: ExRabbitPool.Worker.RabbitConnection,
-  size: 1,
-  max_overflow: 0
-]
-
-{:ok, pid} =
-  ExRabbitPool.PoolSupervisor.start_link(
-    rabbitmq_config: rabbitmq_config,
-    rabbitmq_conn_pool: rabbitmq_conn_pool
-  )
-
-queue = "ex_rabbit_pool"
-exchange = "my_exchange"
-routing_key = "example"
-
-ExRabbitPool.with_channel(:connection_pool, fn {:ok, channel} ->
-  {:ok, _} = AMQP.Queue.declare(channel, queue, auto_delete: true, exclusive: true)
-  :ok = AMQP.Exchange.declare(channel, exchange, :direct, auto_delete: true, exclusive: true)
-  :ok = AMQP.Queue.bind(channel, queue, exchange, routing_key: routing_key)
-end)
-
-{:ok, consumer_pid} = Example.EchoConsumer.start_link(pool_id: :connection_pool, queue: queue)
-
-ExRabbitPool.with_channel(:connection_pool, fn {:ok, channel} ->
-  :ok = AMQP.Basic.publish(channel, exchange, routing_key, "Hello World!")
-  :ok = AMQP.Basic.publish(channel, exchange, routing_key, "Hell Yeah!")
-end)