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Event Consumer and Producer App

Use of external data services in AWS will make charges your account. Please make sure to perform the cleanup per the notes at the bottom of the lab.

The following Lab will demonstrate how to integrate Amazon SQS and Amazon SNS into a simple application that displays messages from a queue and publishes a message to an Amazon SNS Topic. The Amazon SNS Topic will send an email to a defined email address.

Event application
Event application

Requirements​

To develop this application the following requirements will be required.

  • AWS Account with Administrative user

Steps​

Create AWS Identity and Access Management Policies​

First we need to configure permissions in AWS to allow access to Amazon SQS and Amazon SNS. This required portion of the lab is available as a separate artifact in AWS IAM Role.

Create Amazon SQS Queue​

Next an Amazon SQS queue needs to be created. This required portion of the lab is available as a separate artifact in Amazon SQS.

Create Amazon SNS Topic​

With the Amazon SQS queue created, an SNS Topic will be defined. This required portion of the lab is available as a separate artifact in Amazon SNS.

Create a simple app​

Once the resource have been created we first will create a query to read from an Amazon SNS queue.

Create App​

  • Let's display the SQS Message as a Text Input component and a Button component below it.
  • Update the Label to SQS Queue.
  • Update the Button text to Get event.
  • For the SNS Message, place a Text Input component below the previous Text Input / Button components.
  • Update the Label to SNS Topic.
  • Update the Button text to Publish event.

The following demonstrates the previous steps:

Create SQS Query​

  • Go to Code > + > Resource Query and specify a query name of getEventFromSQS.
  • Select Resource set to Amazon SQS resource, Action type set to Receive messages from queue, and a Queue of RetoolQueue.

Note if you want Retool to automatically poll the queue, go to Advanced > Run this query periodically > specify time setting.

  • Once we have the query completed, we need to populate a message in Amazon SQS.

The following demonstrates the previous steps:

Create SNS Query​

Unlike SQS, Retool's SNS Resource will only publish a message to a topic.

  • Go to Code > + > Resource Query and specify a query name of postEventToSNS.
  • Select Resource set to RetoolUniversitySNSTopic, a Topic of RetoolTopic and a message of {{SNSMessage.value}}.

The following demonstrates the previous steps:

Event Handlers​

  • Next we create event handlers for each Button component to invoke the getEventFromSQS and postEventToSNS queries.

The following demonstrates the previous steps:

Create test message using Amazon SQS​

  • Go to the AWS Management Console and select Amazon SQS.
  • In Amazon SQS go to the RetoolQueue and select Send and receive messages.
  • In Message body enter a message:
Hi Retool! This is Amazon SQS queue sending you a quick hello!
  • Select Send message. This will place message into the queue.

The following is an image of the AWS Management Console with Send Message content:

Send messsage
Send messsage

Test App​

  • Select the Get event button and a message should display in the text component.
  • Enter a value into the Publish event text input.
Hi Amazon SNS topic! This is Retool sending you a quick hello!
  • Select the Publish event button.
  • This will generate an email that you will receive in your email inbox.

The following demonstrates the previous steps:

This results in an email notification to the configured endpoint(s).

Notification messsage
Notification messsage