LocalStack Winglang Quickstart

Sample repo for running Winglang applications on LocalStack.

We will take the Voting App example provided by Winglang, deploy it against LocalStack, and run an end-to-end invocation - all running entirely on the local machine!

Prerequisites

• LocalStack
• Node.js v18+, npm
• Python, pip
• Terraform
• awslocal CLI
• make

Installing

To initialize the project and install the dependencies:

$ make install

We also need to apply a small patch in the AWS SDK, to inject the local endpoints (making requests against the LocalStack Gateway under http://localhost:4566). Note that we'll look into making this step obsolete in the future, and provide a more seamless integration!

$ make patch

Deploying

First, make sure that you have LocalStack running in your local Docker, e.g., using the localstack command line interface:

$ localstack start

To compile the sample app and deploy it to LocalStack:

$ make deploy

Once the app is deployed, we can then determine the ID of the API Gateway:

$ awslocal apigateway get-rest-apis | jq -r '.items[0].id'
5t2vuzar6c

Assert that the API Gateway endpoint can be properly invoked:

$ curl -X POST http://5t2vuzar6c.execute-api.localhost.localstack.cloud:4566/prod/requestChoices
["Nori","Ravioli"]

Next, we create a file voting-app/website/public/config.json with the following content (make sure to copy the right API Gateway ID from the output above):

{
    "apiUrl": "http://5t2vuzar6c.execute-api.localhost.localstack.cloud:4566/prod"
}

Finally, we can build and start up the demo web app, which will become available in the browser under http://localhost:3000

$ cd voting-app/website
$ npm install
$ npm run start

Old: Running the "Hello World" Wing app

To compile the app and deploy it to LocalStack:

$ make deploy-hello-world

Once the app is deployed, we can then determine the URL of the deployed SQS queue, and send a message to it (or simply run make test):

$ queueUrl=$(awslocal sqs list-queues --query 'QueueUrls[0]' --output text)
$ awslocal sqs send-message --queue-url $queueUrl --message-body 'LocalStack'

This will then trigger the execution of the "Hello World" Lambda function - you'll observe some logs are printed in the LocalStack container, similar to this:

> START RequestId: 781cd9e6-0798-198a-3b7e-c0c6aee1d017 Version: $LATEST
> END RequestId: 781cd9e6-0798-198a-3b7e-c0c6aee1d017
> REPORT RequestId: 781cd9e6-0798-198a-3b7e-c0c6aee1d017	Init Duration: 726.37 ms	Duration: 894.80 ms	Billed Duration: 895 ms	Memory Size: 1536 MB	Max Memory Used: 165 MB

Finally, we can check out the local S3 buckets, and verify that the hello.txt file was created properly:

$ awslocal s3 ls
2023-01-21 14:26:34 terraform-20230121132624239200000005
2023-01-21 14:26:34 terraform-20230121132624239100000004
$ awslocal s3 cp s3://terraform-20230121132624239200000005/hello.txt /tmp/hello.txt
$ cat /tmp/hello.txt
Hello, LocalStack!

License

This code is available under the Apache License, Version 2.0.