sns-to-websocket

Simple serverless application that takes sns notifications and broadcasts them to websocket connections

Deploying to your account

Install the AWS SAM CLI and use it to package, deploy, and describe your application. These are the commands you'll need to use:

sam package \
	--template-file template.yaml \
	--output-template-file packaged.yaml \
	--s3-bucket REPLACE_THIS_WITH_YOUR_S3_BUCKET_NAME

sam deploy \
	--template-file packaged.yaml \
	--stack-name sns-to-websocket \
	--capabilities CAPABILITY_IAM \
	--parameter-overrides BroadcastTopic=REPLACE_THIS_WITH_YOUR_SNS_TOPIC_ARN

aws cloudformation describe-stacks 	\
	--stack-name sns-to-websocket --query 'Stacks[].Outputs'

Demonstration

To test the WebSocket API, you can use wscat, an open-source command line tool.

1. Install NPM.
2. Install wscat:

$ npm install -g wscat

3. The console output from the stack creation has an outputted value WebSocketURI. You can connect to that endpoint using:

$ wscat -c wss://{YOUR-API-ID}.execute-api.{YOUR-REGION}.amazonaws.com/{STAGE}

4. In a separate console, send a notification to your SNS topic:

$ aws sns publish --topic-arn REPLACE_THIS_WITH_YOUR_SNS_TOPIC_ARN --message "Hello from an SNS topic"

You should see the SNS notification outputted to the console running wscat

Disclaimer

The generated API has no authentication or authorization. If you're working with non-public notifications, consider reading about how to add authorization to an API Gateway.