README.md

go-sqs-consumer

SQS Consumer & Worker for Go

Install

go get github.com/haijianyang/go-sqs-consumer

Quick Start

// create worker for the queue
worker := consumer.New(&consumer.Config{
	Region:   aws.String("region"),
	QueueUrl: aws.String("url"),
}, nil)

// start worker for polling messages
worker.Start(func(message *sqs.Message) error {
	fmt.Println("handle", message)

	return nil
}

Document

Credentials

By default the consumer will look for AWS credentials in the places specified by the AWS SDK.

// consumer will create SQS client for worker
worker := consumer.New(&consumer.Config{
	Region:   aws.String("region"),
	QueueUrl: aws.String("url"),
}, nil)

You can set a instance of the AWS SQS client when create worker.

// init AWS session
sess, err := session.NewSession(&aws.Config{
	Region: aws.String("region")},
)
// init SQS client
svr = sqs.New(sess)

// set SQS client
worker := consumer.New(&consumer.Config{
	Region:   aws.String("region"),
	QueueUrl: aws.String("url"),
}, svr)

Events

worker.On(consumer.EventReceiveMessage, consumer.OnReceiveMessage(func(messages []*sqs.Message) {
	fmt.Println("OnReceiveMessage", messages)
}))

worker.On(consumer.EventProcessMessage, consumer.OnProcessMessage(func(message *sqs.Message) {
		fmt.Println("OnProcessMessage", message)
}))

worker.On(consumer.EventReceiveMessageError, consumer.OnReceiveMessageError(func(err error) {
	fmt.Println("OnReceiveMessageError", err)
}))

Concurrent

func Handler(message *sqs.Message) error {
	fmt.Println("handle", message)

	return nil
}

worker := consumer.New(&consumer.Config{
	Region:   aws.String("region"),
	QueueUrl: aws.String("url"),
}, nil)

// 1. do it yourself
go worker.Start(Handler)
go worker.Start(Handler)
...

// 2. automation
concurrency := 6
worker.Concurrent(Handler, concurrency)

API

consumer.Config

• Region - String - The AWS region.
• AttributeNames - []String - List of queue attributes to retrieve (i.e. ['All', 'ApproximateFirstReceiveTimestamp', 'ApproximateReceiveCount']).
• MaxNumberOfMessages - Int64 - The maximum number of messages to return. Valid values: 1 to 10. Default: 1.
• MessageAttributeNames - []String - The name of the message attribute.
• QueueUrl - String - The URL of the Amazon SQS queue from which messages are received.
• ReceiveRequestAttemptId - String - This parameter applies only to FIFO (first-in-first-out) queues.
• VisibilityTimeout - Int64 - The duration (in seconds) that the received messages are hidden from subsequent retrieve requests after being retrieved by a ReceiveMessage request. Default: 30.
• WaitTimeSeconds - Int64 - The duration (in seconds) for which the call waits for a message to arrive in the queue before returning.
• Idle - Int - The number of worker to sleep.
• Sleep - Int - The duration (in seconds) of worker sleep.

consumer.New(config *Config, svr *sqs.SQS)

Creates a new SQS worker.

• config - Config - The consumer.Config, configuration for worker
• svr - *sqs.SQS - The AWS SQS client

worker.Start(handler Handler)

Start polling the queue for messages.

• handler - func(message *sqs.Message) error - To be called whenever a message is received

worker.On(event string, callback interface{})

Register event listener.

• event - String - The worker events.
• callback - Func - The worker event callback functions.

Worker Events

Event	Func	Description
EventReceiveMessage	OnReceiveMessage func(messages []*sqs.Message)	Fired when messages is received from SQS queue.
EventProcessMessage	OnProcessMessage func(message *sqs.Message)	Fired when a message is successfully processed and removed from the queue.
OnReceiveMessageError	OnReceiveMessageError func(err error)	Fired when receiving messages from SQS queue fail.