Serverless Framework: Serverless Compose Example Project

Technical Stack: AWS, Lambda, Serverless Framework

Read: 10 minutes

Pre-Requisites

To deploy the following Serverless Framework template, you will need the following:

• An AWS account.
• AWS CLI installed locally.
• API credentials for your AWS account configured in your AWS CLI locally by running aws configure.
• Serverless framework installed locally via npm -g install serverless.
• Serverless compose installed locally via npm -g install serverless-compose

Serverless Compose Example Project

Serverless Compose is a plugin for the Serverless Framework that allows you to deploy multiple Serverless projects at once. Each project is deployed as a serperate CloudFormation stack in AWS with its own resources, outputs, and deployment.

Check out the following serverless-compose.yml:

services:
  derezzed-base-infrastructure:
    path: infrastructure/derezzed-base-infrastructure/
  derezzed-db-infrastructure:
    path: infrastructure/derezzed-db-infrastructure/
  derezzed-fastapi-lambda:
    path: lambdas/derezzed-fastapi-lambda/
    dependsOn:
      - derezzed-base-infrastructure
    params:
      derezzedSQSArn: ${derezzed-base-infrastructure.derezzedSQSArn}

services: - You organize your servless projects into seperate services. Each of these services: will create a seperate CloudFormation stack in AWS.

path: - Relative path to the serverless.yml file for your Serverless Framework project.

depdendsOn: - Create dependencies between your Serverless projects. In this example, the derezzed-fastapi-lambda service depends on the derezzed-base-infrastructure service. This means the derezzed-base-infrastructure service will be deployed first.

params: - Pass outputs from one service to another. In this example, the derezzed-base-infrastructure service is passing the sqsRelateAsyncArn output to the derezzed-fastapi-lambda service.

Deploying with Serverless Compose

You will run the normal sls commands to run serverless compose.

sls deploy --stage dev

You can also deploy individual services by running the following command:

sls deploy --stage dev --service derezzed-fastapi-lambda

Your output will look similar to this:

sls deploy --stage dev
Running "serverless" from node_modules

Deploying to stage dev

    ✔  derezzed-base-infrastructure › deployed › 9s
    ✔  derezzed-db-infrastructure › deployed › 10s
    ✔  derezzed-fastapi-lambda › deployed › 50s

Improving Serverless Application Resiliency

Use Serverless Compose to improve the resiliency of your application. Think about splitting important resources like databases, queues, and layers into their own Serverless projects. This allows you to preserve those key resources should you need to delete and redeploy your Lambda functions completely.

You don't want to be the person who accidentally deletes the production database because you were trying to fix a bug in your Lambda function.

Seperate your concerns and use Serverless Compose to deploy them all at once.

Other Serverless Framework Examples

Check out the other Serverless Framework example projects I've created:

• Serverless Framework: Creating an SQS Queue Example
• Serverless Framework: Creating an RDS Serverless Database Example