Go Consumer

GoConsumer is a wrapper around amqp that allows you to easily write applications that consume AMQP queues. Exchange, Queue and bindings are defined in a simple configuration file. GoConsumer handles plumbing those together allowing you to focus on writing great consumer code.

This project borrows many ideas from sparkplug

Configuration

Configuration is done through an ini style file. In this file you define the connection, exchange and queue(s) you want to bind into. Once your file has been loaded and parsed you can attach your consumer function in. The following is an simple configuration file:

[connection]
host = localhost
virtual_host = '/'
user = guest
password = guest
ssl = False

[exchange]
name = grand
type = direct
durable = True
auto_delete = False

[queue]
name = hose
durable = True
auto_delete = True
exclusive = False
routing_key = fire

You can also configure your consumer to draw from multiple queues as well:

[connection]
host = localhost
virtual_host = '/'
user = guest
password = guest
ssl = False

[exchange-app]
name = app
type = direct
durable = True
auto_delete = False

[queue-app]
name = app
durable = True
auto_delete = True
exclusive = False
routing_key = app-event

[exchange-backend]
name = backend
type = direct
durable = True
auto_delete = False

[queue-backend]
name = backend
durable = True
auto_delete = True
exclusive = False
routing_key = backend-event

When multiple queues are being bound, each exchange and queue section should be suffixed with the same value. This defines the binding between the exchange and queue.

Consumers

Consuming functions need to have the following signature:

func(*consumer.Message)

A simple example application would look like:

import (
	"github.com/markstory/go-consumer"
	"log"
)

c, err = consumer.LoadConfig("./consumer.ini")
if err != nil {
	log.Fatalf("Unable to create consumer. Error: %v", err)
}
err = c.Consume(func(msg *consumer.Message) {
	log.Print("Got a message")
	msg.Ack(true)
})

Your consumer function will receive message types that can be acked or nacked as you see fit.

Signals

GoConsumer handles SIGINT, SIGTERM and SIGQUIT. In all cases the it attempts to shutdown the AMQP connection and finish consuming any buffered messages.