Serverless simulation plugin

This is a proof of concept to see if we can replicate Amazon API Gateway using docker images to run lambda

Features:

λ runtimes supported by docker-lambda.
CORS
Authorizer
- Custom Authorizer supported
- Coginito Authorizer not implemented yet
Lambda Integration
- Velocity templates support. supported
Lambda Proxy Integration. supported

Prerequisite

docker - https://docs.docker.com/engine/installation/

Getting Started

Install the plugin

npm i --save-dev serverless-plugin-simulate

Configure your service to use the plugin

service: my-service
provider:
  name: aws
  runtime: nodejs4.3 # python2.7 is also supported

# this is optional configurations
# servicesPathDest is use for the case u want to compile all your src and out
# put to another folder like dist
#
# services allows specifying a docker-compose.yml file and (optional)
# projectName. This will start the docker-compose stack when simulate is run.
# If projectName is specified, it will be used when running docker-compose,
# and the default docker-compose network will be passed to lambda docker commands
# allowing all lambdas to access any hosts defined in docker-compose services
custom:
  simulate:
    dist: dist
    services:
      file: docker-compose.yml
      # will use: $ docker-compose --project-name myproject ...
      # and:      $ docker --network myproject_default ...
      projectName: myproject

plugins:
  - serverless-plugin-simulate

If you do not need to chain functions locally you can just run the API Gateway simulation by itself.

sls simulate apigateway -p 5000

Using the Lambda simulator

If you want to chain functions locally, you need to use the Lambda Simulator.

Run the Lambda Simulation

sls simulate lambda -p 4000

Run the API Gateway Simulation

sls simulate apigateway -p 5000 --lambda-port 4000

Use the environment variables to configure the AWS SDK to use the local Lambda simulation. You can use the same technique with any other AWS SDK.

const AWS = require('aws-sdk');

const endpoint = process.env.SERVERLESS_SIMULATE ?
  process.env.SERVERLESS_SIMULATE_LAMBDA_ENDPOINT :
  undefined

const lambda = new AWS.Lambda({ endpoint })
const handler = (event, context, callback) => {
  const params = {
    FunctionName: 'my-other-function',
    Payload: JSON.stringify({ foo: 'bar' })
  }
  lambda.invoke(params, (err, result) => {
    if (err) {
      return callback(err)
    }

    callback(null, {
      statusCode: 200,
      body: result.Payload
    })
  })
}

Examples

See the examples folder for examples.

npm install - Installs all dependencies
npm start - Starts API Gateway simulation listening at http://localhost:5000
npm run start:lambda - Starts Lambda simulation listening at http://localhost:4000
npm run start:apigateway - Starts API Gateway simulation that uses the Lambda simulation listening at http://localhost:5000
npm run start:services - Starts mock services defined in docker-compose.yml
npm test - tests custom authorizer (Authorization:TOKEN 12345)

Authors

Gert JvR - Initial work - gertjvr
John McKim - johncmckim

See also the list of contributors who participated in this project.

Contributing

Please create an issue before submitting an Pull Request.

Acknowledgements

This would not be possible without lambci

docker-lambda - Docker images and test runners that replicate the live AWS Lambda environment

@johncmckim for suggesting the idea

gertjvr / serverless-plugin-simulate