Components as microservices

SOA in the front-end world

Matteo Figus / @matteofigus

@matteofigus

Coding, technology, conferences
London, UK
OpenTable

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more than 32K restaurants worldwide

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Europe, North and South America, Asia

millions of requests per minute

more than 50 engineers make changes every day

Agenda

Microsites architecture
OpenComponents architecture
Agile in the front-end world

The Microsites architecture

Step #1 - Dismantling the monolith

Continuous delivery in dates

2012 - Setup continuous integration pipeline

2013 - All the code moved to github

2014 - First project implements continous deployment

2015 - 10+ deployments per day

couple days ago - New engineer makes 1 PR and gets its code to prod on day 1

The monolithic architecture (2012)

Unique giant DB managed by DBAs
Stored procedures to handle data
Huge .NET applications dialing directly with the DB

The monolith

Deployments every 15 days

Not very resilient

Not very robust

Code consistency (one single language)

Dedicated team for infrastructure

Dedicated team for testing

A couple of years later...

Microsites

www.opentable.com/san-francisco-restaurants

"start" microsite
San Francisco metro
=> http://start-123/?domain=com&metro=4

Microsites

Team of 2 to 4 full-stack engineers
Minimal complexity
Minimal dependencies
Easier to test, maintain, extend
Multiple daily deployments
Ownership

The common parts

Microsite rendering (server-side)

http://search-456/?metro=4&dateTime=2015-10-23T19:00
Execute logic
GET shared components from Components API

<html>
  <head>
    <!-- css component -->
    <!-- js head component -->
    ...
  </head>
  <body>
    <!-- header component -->
    ...
    <!-- footer component -->
    <!-- js body component -->
    ...
  </body>
</html>

Components for common UI elements

$ curl http://components-789/header/1.X.X/?userType=Admin&metroId=72 -H Accept-Language:en-US

{
  "href": "http://components-789/header/1.X.X?userType=Admin&metroId=72",aefaef
  "html": "<div><img src=\"//srs.opentable.com/logo.jpg\" />...</div>"
}

Microsites + Shared components

Consistency

Coordination

Optimal front-end loading

Easy to spin-up new microsites

OpenComponents

A framework for developing and deploying HTML components

github.com/opentable/oc

Demo time!

Getting started

$ npm install -g oc

$ mkdir demo && cd demo
$ oc init test-component jade
$ echo 'div this is my component' > test-component/template.jade

$ oc dev . 3030
$ oc preview http://localhost:3030/test-component

Ship it!

$ oc registry add http://oc-registry.herokuapp.com
$ oc publish /test-component

$ oc preview http://oc-registry.herokuapp.com/test-component

Static resources? Let me handle this!

// template.jade

img(src=staticPath+'img/img.jpg')

// server.js

module.exports.data = function(context, cb){
  cb(null, {
    staticPath: context.staticPath
  });
};

Client-side rendering

<html>
  <body>
    ...
    <oc-component href="http://oc-registry.com/component/1.X.X/?a=b">
    </oc-component>
    ...
    <script src="http://oc-registry.com/oc-client/client.js">
    </script>
  </body>
</html>

Server-side rendered components

$ curl http://oc-registry.com/hello-world

{
  "href": "https://oc-registry.com/hello-world",
  "name": "hello-world",
  "version": "1.0.0",
  "requestVersion": "",
  "html": "<div>hello John Doe</div>",
  "type": "oc-component",
  "renderMode": "rendered"
}

Server-side unrendered components

$ curl http://oc-registry.com/hello-world 
-H Accept:application/vnd.oc.unrendered+json
{
  "href": "https://oc-registry.com/hello-world",
  "name": "hello-world",
  "version": "1.0.0",
  "requestVersion": "",
  "data": { "name": "John doe" },
  "template": {
    "src": "https://s3.amazonaws.com/your-s3-bucket/components/hello-world/1.0.0/template.js",
    "type": "handlebars",
    "key": "cad2a9671257d5033d2abfd739b1660993021d02"
  },
  "type": "oc-component",
  "renderMode": "unrendered"
}

Server-side rendering with node.js

npm install oc-client --save

var Client = require('oc-client'),
    client = new Client({
      registries: {
        serverRendering: 'http://oc-registry.intranet/'
        clientRendering: 'http://oc-registry.com/'
      },
      components: {'hello-world': '~1.0.0'}
    });

client.renderComponent('hello-world', function(err, componentHtml){
  console.log(componentHtml); // => rendered html
});