Running SQS and SNS services locally

For this purpose we use the public localstack docker image. To see more documentation please see the following repository: https://github.com/localstack/localstack

First set a new profile for aws on your system. Set test as aws_access_key_id and aws_secret_access_key . Set us-east-1 for the region in the profile configuration.

aws configure --profile localstack

By default on the docker-compose.yml for the localstack service Under volume we run always a setup script tha can be found in the following path /scripts/localstack-entrypoint

This script configures localstack we an exact replica of the cloud configuration.

List of Queues (SQS).

For the most cases we have one normal queue and one dead letter queue for each microservice.

• demo-[env]-sales
• demo-[env]-inventory
• demo-[env]-notifications

*[env] can be replaced by local (default) on local setup(see /scripts/localstack-entrypoint), development, staging, production

List of Topics (SNS).

There is a topic for each microservice

• demo-[env]-sales
• demo-[env]-inventory
• demo-[env]-notifications

Subscriptions (SNS)

Sales

This queue listens to the following topics

• notifications
• inventory

Inventory

This queue listens to the following topics

• sales
• notifications

Notifications

This queue listens to the following topics

• sales
• inventory

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To build the image and have it ready run the following command in the current workspace.

docker-compose up localstack

When you see the following message Localstack is ready. This means localstack has been successfully setup.

Before you can start the other microservices we need to change some environment variables please make sure all your .env files under packages have the following configuration

AWS_SNS_TOPIC_ARN_PREFIX=arn:aws:sns:us-east-1:000000000000
AWS_SQS_QUEUE_DOMAIN=http://localstack:4566/000000000000
AWS_ACCESS_KEY=test
AWS_SECRET_KEY=test
AWS_REGION=us-east-1
LOCALSTACK_ENDPOINT=http://localstack:4566

*Note1:You can interchange the variable localstack for host.docker.internal on the urls. (Windows only fix)

To start the other microservices run the following command

docker-compose up sales inventory notifications

To check the setup is done we can try the following commands

1)To list all sqs queues

aws --endpoint-url=http://localhost:4566 sqs list-queues --profile localstack

2)To list all topics

aws --endpoint-url=http://localhost:4566 sns list-subscriptions --profile localstack

3)To purge all queues (deletes all messages from quues)

aws sqs purge-queue --endpoint-url=http://localhost:4566 --queue-url http://localhost:4566/000000000000/annise-local-sales --profile localstack
aws sqs purge-queue --endpoint-url=http://localhost:4566 --queue-url http://localhost:4566/000000000000/annise-local-inventory --profile localstack
aws sqs purge-queue --endpoint-url=http://localhost:4566 --queue-url http://localhost:4566/000000000000/annise-local-sales --profile localstack

• To send a message (Example: this emits theSales:created topic in the notifications queue). Basically the message should be stringified in the message-body param.

  aws sqs send-message --endpoint-url=http://localhost:4566 --profile localstack --queue-url http://localhost:4566/000000000000/demo-local-notifications --message-body “{\“Subject\“:\“Sales:created\“,\“Message\“:\“{\“quantity\“:30,\“amount\“:10,\“date\“:\“2021-12-01\“,\“vehicleId\“:2,\“userId\“:1}\“}”
  
  

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NOTE: Sometimes when restarting the container, the services hang indefinitely with the following message. Waiting for all LocalStack services to be ready. If this is the case please remove the container with the following command to fix the issue for now.

docker rm demo_localstack

And restart the localstack container