docker-lambda-api-server

A companion tool for the awesome docker-lambda sandbox.

This is a very basic, local AWS Lambda API server that lets you invoke your lambda functions via the AWS SDK instead of running Docker from the command-line or docker-lambda Node helper.

It also leverages (although very limited at this point) the new AWS Cloudformation SAM template.

Prerequisites

Same as docker-lambda.

Installation

npm install docker-lambda-api-server

Example

Let's suppose you have 2 functions: hello and goodbye.

// hello.js
exports.handler = function(event, context, cb) {
  cb(null, JSON.stringify({hello: 'world'}))
}

// goodbye.js
exports.handler = function(event, context, cb) {
  cb(null, JSON.stringify({good: 'bye'}))
}

First thing you need to do (if you haven't already), is to create a SAM template like this:

# /greetings.yml
AWSTemplateFormatVersion: '2010-09-09'
Transform: AWS::Serverless-2016-10-31
Resources:
  SayHello:
    Type: AWS::Serverless::Function
    Properties:
      Handler: hello.handler
      Runtime: nodejs4.3
 
  SayGoodbye:
    Type: AWS::Serverless::Function
    Properties:
      Handler: goodbye.handler
      Runtime: nodejs4.3

As you can see above, we created the definition for our 2 functions, which we named SayHello and SayGoodbye, each one pointing to the right code file.

We are now ready to start the API server:

docker-lambda-api-server -f greetings.yml

An HTTP server will start listening at localhost:3000. You can do a quick test by invoking any of your functions via the AWS Lambda REST API:

curl http://localhost:3000/2015-03-31/functions/SayHello/invocations

{"hello":"world"}

Or you can also invoke the function via the AWS SDK:

import { Lambda } from 'aws-sdk'

let lambda = new Lambda({
  region: 'foo-west-1',
  endpoint: 'http://localhost:3000'
})

lambda
  .invoke({ FunctionName: 'SayGoodbye' })
  .promise()
  .then(result => console.log(result))

Documentation

// TODO

In the meanwhile, you can run

docker-lambda-api-server -h

to see all the options available.

You can also check out the provided example.

TODO

• Unit tests?
• Proper runtime validation (node, node4.3)
• Implement ClientContext
• Implement InvocationType
• Implement Qualifier
• Implement LogType
• Implement environment variables in SAM template
• Your suggestion here