Skip to content

Instantly share code, notes, and snippets.

@lukebakken
Last active February 27, 2018 15:55
Show Gist options
  • Star 0 You must be signed in to star a gist
  • Fork 0 You must be signed in to fork a gist
  • Save lukebakken/4c390610ed44594d5be5450373a54504 to your computer and use it in GitHub Desktop.
Save lukebakken/4c390610ed44594d5be5450373a54504 to your computer and use it in GitHub Desktop.
// This example declares a durable Exchange, an ephemeral (auto-delete) Queue,
// binds the Queue to the Exchange with a binding key, and consumes every
// message published to that Exchange with that routing key.
//
package main
import (
"flag"
"fmt"
"github.com/streadway/amqp"
"log"
"time"
)
var (
uri = flag.String("uri", "amqp://guest:guest@localhost:5672/", "AMQP URI")
exchange = flag.String("exchange", "test-exchange", "Durable, non-auto-deleted AMQP exchange name")
exchangeType = flag.String("exchange-type", "direct", "Exchange type - direct|fanout|topic|x-custom")
queue = flag.String("queue", "test-queue", "AMQP queue name")
bindingKey = flag.String("key", "test-key", "AMQP binding key")
consumerTag = flag.String("consumer-tag", "simple-consumer", "AMQP consumer tag (should not be blank)")
autoDelete = flag.Bool("auto-delete", false, "Should queue be auto-delete or not (default is false)")
lifetime = flag.Duration("lifetime", 5*time.Second, "lifetime of process before shutdown (0s=infinite)")
)
func init() {
flag.Parse()
}
func main() {
c, err := NewConsumer(*uri, *exchange, *exchangeType, *queue, *bindingKey, *consumerTag, *autoDelete)
if err != nil {
log.Fatalf("%s", err)
}
if *lifetime > 0 {
log.Printf("running for %s", *lifetime)
time.Sleep(*lifetime)
} else {
log.Printf("running forever")
select {}
}
log.Printf("shutting down")
if err := c.Shutdown(); err != nil {
log.Fatalf("error during shutdown: %s", err)
}
}
type Consumer struct {
conn *amqp.Connection
channel *amqp.Channel
tag string
done chan error
}
func NewConsumer(amqpURI, exchange, exchangeType, queueName, key, ctag string, autoDelete bool) (*Consumer, error) {
c := &Consumer{
conn: nil,
channel: nil,
tag: ctag,
done: make(chan error),
}
var err error
log.Printf("dialing %q", amqpURI)
c.conn, err = amqp.Dial(amqpURI)
if err != nil {
return nil, fmt.Errorf("Dial: %s", err)
}
go func() {
fmt.Printf("closing: %s", <-c.conn.NotifyClose(make(chan *amqp.Error)))
}()
log.Printf("got Connection, getting Channel")
c.channel, err = c.conn.Channel()
if err != nil {
return nil, fmt.Errorf("Channel: %s", err)
}
log.Printf("got Channel, declaring Exchange (%q)", exchange)
if err = c.channel.ExchangeDeclare(
exchange, // name of the exchange
exchangeType, // type
true, // durable
false, // delete when complete
false, // internal
false, // noWait
nil, // arguments
); err != nil {
return nil, fmt.Errorf("Exchange Declare: %s", err)
}
log.Printf("declared Exchange, declaring Queue %q", queueName)
args := make(amqp.Table)
args["x-expires"] = int32(10000)
queue, err := c.channel.QueueDeclare(
queueName, // name of the queue
true, // durable
autoDelete, // delete when unused
false, // exclusive
false, // noWait
args, // arguments
)
if err != nil {
return nil, fmt.Errorf("Queue Declare: %s", err)
}
log.Printf("declared Queue (%q %d messages, %d consumers), binding to Exchange (key %q)",
queue.Name, queue.Messages, queue.Consumers, key)
if err = c.channel.QueueBind(
queue.Name, // name of the queue
key, // bindingKey
exchange, // sourceExchange
false, // noWait
nil, // arguments
); err != nil {
return nil, fmt.Errorf("Queue Bind: %s", err)
}
log.Printf("Queue bound to Exchange, starting Consume (consumer tag %q)", c.tag)
deliveries, err := c.channel.Consume(
queue.Name, // name
c.tag, // consumerTag,
false, // noAck
false, // exclusive
false, // noLocal
false, // noWait
nil, // arguments
)
if err != nil {
return nil, fmt.Errorf("Queue Consume: %s", err)
}
go handle(deliveries, c.done)
return c, nil
}
func (c *Consumer) Shutdown() error {
// will close() the deliveries channel
if err := c.channel.Cancel(c.tag, true); err != nil {
return fmt.Errorf("Consumer cancel failed: %s", err)
}
if err := c.conn.Close(); err != nil {
return fmt.Errorf("AMQP connection close error: %s", err)
}
defer log.Printf("AMQP shutdown OK")
// wait for handle() to exit
return <-c.done
}
func handle(deliveries <-chan amqp.Delivery, done chan error) {
for d := range deliveries {
log.Printf(
"got %dB delivery: [%v] %q",
len(d.Body),
d.DeliveryTag,
d.Body,
)
d.Ack(false)
}
log.Printf("handle: deliveries channel closed")
done <- nil
}
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment