serverless-rack

A Serverless v1.x plugin to build your deploy Ruby Rack applications using Serverless. Compatible Rack application frameworks include Sinatra and Padrino.

Features

• Transparently converts API Gateway and ALB requests to and from standard Rack requests
• Supports anything you'd expect from Rack such as redirects, cookies, file uploads etc.

Coming soon

• Bundler integration, including dockerized bundling
• Convenient rack serve command for serving your application locally during development
• CLI commands for remote execution of Ruby code (rack exec) and shell commands (rack command)

Install

sls plugin install -n serverless-rack

This will automatically add the plugin to package.json and the plugins section of serverless.yml.

Sinatra configuration example

project
├── api.rb
├── config.ru
├── Gemfile
└── serverless.yml

api.rb

A regular Sinatra application.

require 'sinatra'

get '/cats' do
  'Cats'
end

get '/dogs/:id' do
  'Dog'
end

config.ru

require './api'
run Sinatra::Application

serverless.yml

All functions that will use Rack need to have rack_adapter.handler set as the Lambda handler and use the default lambda-proxy integration for API Gateway. This configuration example treats API Gateway as a transparent proxy, passing all requests directly to your Sinatra application, and letting the application handle errors, 404s etc.

service: example

provider:
  name: aws
  runtime: ruby2.5

plugins:
  - serverless-rack

functions:
  api:
    handler: rack_adapter.handler
    events:
      - http: ANY /
      - http: ANY {proxy+}

Gemfile

Add Sinatra to the application bundle.

source 'https://rubygems.org'

gem 'sinatra'

Deployment

Simply run the serverless deploy command as usual:

$ bundle install --path vendor/bundle
$ sls deploy