heroku_slides.md

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#Babel on Heroku await yourHerokuBill

layout: false .left-column[

Heroku in 60 seconds

] .right-column[ Heroku is a Platform as a Service(PaaS)

• Supports numerous languages
• Relatively simple and easily customizable build process
• Very stable and mature support for Node.js
• Deploys via git push master
• However comes with several notable restrictions
  • Nothing can be persisted to disk between deploys
  • No access to the box (SSH) ]

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What Heroku does when you deploy

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What Heroku does when you deploy

• npm install

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What Heroku does when you deploy

• npm install
• Shutdown the previous version (connections will queued and held open)

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What Heroku does when you deploy

• npm install
• Shutdown the previous version (connections will queued and held open)
• Launch the new service

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What Heroku does when you deploy

• npm install
• Shutdown the previous version (connections will queued and held open)
• Launch the new service
• Connections will be routed to the new instance

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Basics of a Heroku Node.js Instance

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Basics of a Heroku Node.js Instance

Procfile contains the basic instructions needed to run the app

web: node index.js

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Basics of a Heroku Node.js Instance

package.json

• Declares which version of node you require

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Basics of a Heroku Node.js Instance

package.json

"engines": {
    "node": "4.1.1"
}

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Basics of a Heroku Node.js Instance

package.json

• Declares which version of node you require
• Specifies your dependencies for Heroku

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What you should do to help Heroku

• Move any slow build steps the 'npm install' process

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What you should do to help Heroku

• Move any slow build steps the 'npm install' process

  ...
  "scripts": {
    "start": "node index.js"
    "postinstall": "babel -d dist server"
  },

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What you should do to help Heroku

• Move any slow build steps the 'npm install' process

  ...
  "scripts": {
    "start": "node index.js"
    "postinstall": "babel -d dist server"
  },

• Ensure that the launching of the new service is fast
  • Connections are paused until the new service starts listening on the assigned port

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To the code

Two ways to accomplish adding Babel to your Heroku app

1. require('babel/register')
2. Prebuild the JavaScript files in the 'postinstall' step

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babel/register

index.js

require('babel/register');
server = require('./server');

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Prebuild

package.json

  "scripts": {
    "postinstall": "make build",
    "start": "node index.js"
  },

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Prebuild

Makefile

build: clean babel

clean:
	rm -rf build
	mkdir -p build

babel:
	babel -d build server/index.js
	rsync -av --include \*/ --include \*.json --exclude \*  ./server/ ./build/server/
	rsync -av --include \*/ --include \*.ejs --exclude \*  ./server/ ./build/server/

.PHONY: build clean

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Complete example on github

• https://github.com/mdp/baroku
• Precompile branch
• 'babel/register' branch