dromedary-serverless

Overview

This project deploys dromedary in AWS Lambda with API Gateway as the interface to demonstrate serverless architecture. It also demonstrates the use of CodePipeline with Lambdas to continuously deliver changes made in the source code in a serverless manner.

Architecture Overview

The application is split into 2 separate parts for deployment:

• API - deployed as a Lambda function using API Gateway for the front end.
• Static Content - deployed into an S3 bucket with website hosting enabled.

Additionally, a config.json file is generated and deployed into the S3 bucket containing the endpoint to use for the API in API Gateway.

Pipeline Overview

The pipeline consists of the following steps:

• commit - a commit in GitHub triggers a new CodePipeline job. The source is downloaded from GitHub and then pushed into an S3 bucket as a zip file.
• npm lambda - a lambda is executed that downloads the source zip file, runs npm install to get he dependencies and then uploads the source+dependencies to S3 as a tarball.
• gulp lambda(s) - a lambda is executed that downloads the source+dependencies tarball from S3, extracts it, then runs a gulp task

The details of what happens in the gulp task is completely owned by the gulpfile.js in the source code. This provides decoupling of the pipeline from the app and allows the pipeline template to be used by any gulp project.

Here's a sample of what the pipeline looks like in AWS CodePipeline console:

Launching Pipeline

To integrate with GitHub, AWS CodePipeline uses OAuth tokens. Generate your token at GitHub and ensure you enable the following two scopes:

• admin:repo_hook, which is used to detect when you have committed and pushed changes to the repository
• repo, which is used to read and pull artifacts from public and private repositories into a pipeline

You can launch via the console:

Or you can launch by using gulp in this repo:

• PREREQUISITES - You need Node.js installed.
  • Install Node.js: sudo yum install nodejs npm --enablerepo=epel (For OS X, check out nodejs.org)
  • Update NPM: curl -L https://npmjs.org/install.sh | sudo sh
  • Install Gulp: sudo npm install -g gulp
• Download this repo and then run npm install first to install all dependent modules.
• Bring the pipeline up with gulp pipeline:up --token=XXXXXXXXXXXXXXXXX
• You can run gulp pipeline:wait to wait for the stack to come up, and then gulp pipeline:status to get the outputs and gulp pipeline:stacks to see what applicaiton stacks the pipeline has currently running.
• To tear everything down, run gulp pipeline:teardown
• By default, the stack name will be dromedary-serverless-pipeline. You can change this by passing --stackName=my-stack-name to any of the above gulp commands.

Development

To do local development of the CFN or Gulp tasks, you'll want to link in the submodules with npm run-script submodules

To publish your app template changes, run gulp app:cfn:publish. You will likely want to choose a different bucket to publish the templates and lambda code to via the --templateBucket argument. Be sure to then reference that same bucket name in your gulpfile.js for cfnBucket.

To publish your pipeline template/lambda changes, run gulp pipeline:cfn:publish. You will likely want to choose a different bucket to publish the templates and lambda code to via the --templateBucket argument. Be sure to then reference that same bucket name when you pipeline:up.

Todo

• Tighten up IAM policies in CFN
• Production deployment in pipeline
• Extract out /app directory to generic module named gulp-serverless-app to enable running Express Node.js apps in AWS with Lambda and API Gateway.
• Extract out /pipeline directory to generic module named gulp-serverless-pipeline to enable running CodePipeline with Gulp for other applications.