aws-fanout

AWS-Fanout

A library wrapping SNS and SQS to allow for human readable names when using a fanout technique. Now you use the fanout pattern without needing to hard code ARNS throughout your application!

Installation

This module is installed via npm:

$ npm install aws-fanout

Example Usage

import { subscribeQueuesToTopics, publish } from 'aws-fanout'

const queueName = 'post-office'
const topicNames = ['send-email']

await subscribeQueuesToTopics(credentials, topicNames, queueName)

await publish(credentials, 'send-email', {
  address: '[e-mail]',
  subject: 'Good Morning John',
})

Environment Variables

AWS_FANOUT_RATE_LIMIT_MS

Default value: 10

The API calls to SQS/SNS are rate limited.

By default there is a maximum of one request made per 10ms. This results in a maximum of 100 requests per second.

API v2 Documentation

• createQueue(credentials, { queueName })
• createTopic(credentials, { topicName })
• deleteQueue(credentials, { queueName })
• deleteTopic(credentials, { topicName })
• publishMessage(credentials, { topicName, message })
• receiveMessage(credentials, { queueName, maxNumberOfMessages, visibilityTimeout })
• deleteMessage(credentials, { queueName, receiptHandle })
• setQueuePolicy(credentials, { queueName, topicNames, ignoreExistingPolicy })
• setQueueRedrivePolicy(credentials, { queueName, deadLetterQueueName, maxReceiveCount })
• subscribeQueueToTopic(credentials, { queueName, topicName })

v2.createQueue

Create a single queue on SQS.

• credentials: Credentials
• options.queueName: name of the queue to create

import { createQueue } from 'aws-sdk'

await createQueue(credentials, {
  queueName: 'logger'
})

v2.createTopic

Create a single topic on SNS.

• credentials: Credentials
• options.topicName: name of the topic to create

import { createTopic } from 'aws-sdk'

await createTopic(credentials, {
  topicName: 'create-account'
})

v2.deleteQueue

Delete a queue.

• credentials: Credentials
• options.queueName: name of the queue to delete

import { deleteQueue } from 'aws-sdk'

await deleteQueue(credentials, {
  queueName: 'my-queue-name'
})

v2.deleteTopic

Delete a topic.

• credentials: Credentials
• options.topicName: name of the topic to delete

import { deleteTopic } from 'aws-sdk'

await deleteTopic(credentials, {
  topicName: 'my-topic-name'
})

v2.publishMessage

Publish a message with a particular topic. Any queues that are subscribed to the topic will receive a copy of it.

• credentials: Credentials
• options.topicName: name of the topic
• options.message: message payload to send, must be a string

import { subscribeQueueTopicsByTheirPrefix } from 'aws-sdk'

await publish(credentials,
  topicName: 'create',
  message: JSON.stringify({
    userId: 123,
    email: '[e-mail]'
  })
)

v2.receiveMessage

Listen for messages on the queue.

• credentials: Credentials
• options.maxNumberOfMessages: Maximum number of messages to retrieve
• options.visibilityTimeout: The duration (in seconds) that the received messages are hidden from subsequent retrieve requests
• options.queueName: Name of the queue to receive messages from

import { receiveMessage } from 'aws-sdk'

const messages = await receiveMessage(
  credentials,
  maxNumberOfMessages: 5,
  visibilityTimeout: 15,
  queueName: 'actions'
)

v2.deleteMessage

Remove a message from a queue.

After you have finished receiving a message from the queue, you should remove it so that it does not get sent again.

• credentials: Credentials
• options.queueName: name of the queue to delete the message from
• options.receiptHandle: the receipt handle of the mesage to delete

import { receiveMessage, deleteMessage } from 'aws-sdk'

const queueName = 'my-queue-name'

const messages = await receiveMessage(credentials, {
  maxNumberOfMessages: 1,
  visibilityTimeout: 10,
  queueName
})

if (messages.length > 0) {
  await deleteMessage(credentials, {
    queueName,
    receiptHandle: messages[0].ReceiptHandle
  })
}

v2.setQueuePolicy

Subscribes a queue to a list of topics.

If the queue or topics do not exist, they will be created.

• credentials: Credentials
• options.queueName: queue to forward topics to
• options.topicNames: list of topics to subscribe to
• options.ignoreExistingPolicy: whether to preserve any existing topics that have previously been allowed to post to this queue.

import { subscribeQueuesToTopics } from 'aws-sdk'

await subscribeQueuesToTopics(credentials, {
  queueName: 'actions',
  topicNames: ['create', 'read', 'update', 'destroy'],
  ignoreExistingPolicy: false
})

If you have a large number of topics to create, you may start hitting the AWS limit on how large the queue policy can be. Instead you can define the queue to accept any topic that matches a wildcard pattern.

import { subscribeQueuesToTopics } from 'aws-sdk'

await subscribeQueuesToTopics(credentials, {
  queueName: 'logger',
  topicNames: ['*'],
  ignoreExistingPolicy: false
})

v2.setQueueRedrivePolicy

• credentials: Credentials
• options.deadLetterQueueName: (optional) The name of dead-letter queue to which SQS moves messages after the value of "maxReceiveCount" is exceeded.
• options.maxReceiveCount: (optional, default = 5) The number of times a message is delivered to the source queue before being moved to the dead-letter queue. When the ReceiveCount for a message exceeds the maxReceiveCount for a queue, SQS moves the message to the dead-letter-queue.

import { setQueueRedrivePolicy } from 'aws-sdk'

await setQueueRedrivePolicy(credentials, {
  queueName: 'actions',
  deadLetterQueueName: 'deadLetter',
  maxReceiveCount: 5
})

v2.subscribeQueueToTopic

Subscribe a queue to a topic.

When the topic is published, a copy of it will be sent to the queue.

• credentials: Credentials
• options.queueName: name of the queue
• options.topicName: name of the topic

import { subscribeQueueToTopic } from 'aws-sdk'

await subscribeQueueToTopic(credentials, {
  queueName: 'actions',
  topicName: 'create'
})

API v1 Documentation

• registerQueues(credentials, queueNames)
• registerTopics(credentials, topicNames)
• deleteQueue(credentials, queueName)
• deleteTopic(credentials, topicName)
• publish(credentials, topicName, message)
• receiveMessage(credentials, maxNumberOfMessages, visibilityTimeout, queueName)
• deleteMessage(credentials, queueName, receiptHandle)
• subscribeQueueTopicsByTheirPrefix(credentials, topicNames, queueName, [deadLetterQueueName], [maxReceiveCount=5]
• subscribeQueuesToTopics(credentials, topicNames, queueName, [deadLetterQueueName], [maxReceiveCount=5])

v1.registerQueues

Create multiple queues on SQS.

• credentials: Credentials
• queueNames: list of queues to create

import { registerQueues } from 'aws-sdk'

const queueNames = [
  'logs',
  'errors',
  'actions',
]

await registerQueues(credentials, queueNames)

v1.registerTopics

Create multiple topics on SNS.

• credentials: Credentials
• topicNames: list of topics to create

import { registerTopics } from 'aws-sdk'

const topicNames = [
  'create-account',
  'read-account',
  'update-account',
  'destroy-account',
]

await registerTopics(credentials, topicNames)

v1.deleteQueue

Delete a queue.

• credentials: Credentials
• queueName: name of the queue to delete

import { deleteQueue } from 'aws-sdk'

const queueName = 'my-queue-name'

await deleteQueue(credentials, queueName)

v1.deleteTopic

Delete a topic.

• credentials: Credentials
• topicName: name of the topic to delete

import { deleteTopic } from 'aws-sdk'

const topicName = 'my-topic-name'

await deleteTopic(credentials, topicName)

v1.publish

Publish a message with a particular topic. Any queues that are subscribed to the topic will receive a copy of it.

The message will be serialized using JSON.stringify.

• credentials: Credentials
• topicName: name of the topic
• message: message payload to send

import { subscribeQueueTopicsByTheirPrefix } from 'aws-sdk'

const topicName = 'create'
const message = {
  userId: 123,
  email: '[e-mail]'
}

await publish(credentials, topicName, message)

v1.receiveMessage

Listen for messages on the queue.

• credentials: Credentials
• maxNumberOfMessages: Maximum number of messages to retrieve
• visibilityTimeout: The duration (in seconds) that the received messages are hidden from subsequent retrieve requests
• queueName: Name of the queue to receive messages from

import { receiveMessage } from 'aws-sdk'

const maxNumberOfMessages = 5
const visibilityTimeout = 15
const queueName = 'actions'

const messages = await receiveMessage(
  credentials,
  maxNumberOfMessages,
  visibilityTimeout,
  queueName
)

v1.deleteMessage

Remove a message from a queue.

After you have finished receiving a message from the queue, you should remove it so that it does not get sent again.

• credentials: Credentials
• queueName: name of the queue to delete the message from
• receiptHandle: the receipt handle of the mesage to delete

import { receiveMessage, deleteMessage } from 'aws-sdk'

const queueName = 'my-queue-name'

const messages = await receiveMessage(credentials, 1, 10, queueName)
if (messages.length > 0) {
  const receiptHandle = messages[0].ReceiptHandle
  await deleteMessage(credentials, queueName, receiptHandle)
}

v1.subscribeQueuesToTopics

Subscribes a queue to a list of topics.

If the queue or topics do not exist, they will be created.

• credentials: Credentials
• topicNames: list of topics to subscribe to
• queueName: queue to forward topics to
• deadLetterQueueName: (optional) The name of dead-letter queue to which SQS moves messages after the value of "maxReceiveCount" is exceeded.
• maxReceiveCount: (optional, default = 5) The number of times a message is delivered to the source queue before being moved to the dead-letter queue. When the ReceiveCount for a message exceeds the maxReceiveCount for a queue, SQS moves the message to the dead-letter-queue.

import { subscribeQueuesToTopics } from 'aws-sdk'

const topicNames = ['create', 'read', 'update', 'destroy']
const queueName = 'actions'
const deadLetterQueueName = 'dead-letter'
const maxReceiveCount = 5

await subscribeQueuesToTopics(
  credentials,
  topicNames,
  queueName,
  deadLetterQueueName,
  maxReceiveCount
)

v1.subscribeQueueTopicsByTheirPrefix

If you have a large number of topics to create, you may start hitting the AWS limit on how large the queue policy can be.

Instead you can define the queue to accept any topic that matches a wildcard.

• credentials: Credentials
• topicNames: list of topics to subscribe to
• queueName: queue to forward topics to
• deadLetterQueueName: (optional) The name of dead-letter queue to which SQS moves messages after the value of "maxReceiveCount" is exceeded.
• maxReceiveCount: (optional, default = 5) The number of times a message is delivered to the source queue before being moved to the dead-letter queue. When the ReceiveCount for a message exceeds the maxReceiveCount for a queue, SQS moves the message to the dead-letter-queue.

import { subscribeQueueTopicsByTheirPrefix } from 'aws-sdk'

const topicNames = ['create', 'read', 'update', 'destroy']
const queueName = 'actions'
const deadLetterQueueName = 'dead-letter'
const maxReceiveCount = 5

await subscribeQueueTopicsByTheirPrefix(
  credentials,
  topicNames,
  queueName,
  deadLetterQueueName,
  maxReceiveCount
)

Credentials

The credentials object is passed through to the SNS/SQS constructor.

• SQS Constructor API Docs
• SNS Constructor API Docs

If you are using IAM roles or a shared credentials file, you can just leave this empty.

Reference: Setting AWS Credentials in Node.js

If you want to load credentials from environment variables, then you can do something like this:

const credentials = {
  region: process.env.AWS_REGION,
  accessKeyId: process.env.AWS_ACCESS_KEY_ID,
  secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY,
}