Chef Workshop

Outline

Let's use Chef to make a site that does stuff

Slides

Follow along at:
http://mkropat.github.io/presentation-chef-workshop/
Keep in mind: the slides are boring
All the interesting bits come from the questions you ask
Also: typing in the Chef-y bits helps you learn

Pre-Requisites

Vagrant

$ mkdir chef-workshop
$ cd chef-workshop
$ vagrant init chef/centos-6.6
A `Vagrantfile` has been placed in this directory...

Vagrant (cont.)

./Vagrantfile

Vagrant.configure(2) do |config|
  config.vm.box = "chef/centos-6.6"
  config.vm.network "forwarded_port", guest: 8080, host: 8080
end

Vagrant (cont.)

$ vagrant up
Bringing machine 'default' up with 'virtualbox'
provider...
$ vagrant ssh
Last login: Thu Jan 15 16:32:07 2015 from 10.0.2.2
[vagrant@localhost ~]$

Directory Skeleton

Install Knife Solo:

chef exec gem install knife-solo

Directory Skeleton (cont.)

Create the directory skeleton:

knife solo init .

Directory Skeleton (cont.)

./.chef
./.chef/knife.rb
./.gitignore
./Berksfile
./cookbooks
./data_bags
./environments
./nodes
./roles
./site-cookbooks

A Cookbook Appears

knife cookbook create animal-www -o site-cookbooks/

A Cookbook Appears (cont.)

./attributes
./definitions
./files/default
./libraries
./metadata.rb
./providers
./README.md
./recipes/default.rb
./resources
./templates/default

An Awesome Site

./www/index.html

<!DOCTYPE html>
<html>
<head><title>Animals R Fun</title></head>
<body>
  <p>Can I haz animals?</p>
  <ul><li>Aardvarks</li><li>Yeti Crab</li></ul>
</body>
</html>

An Awesome Site (cont.)

./site-cookbooks/animal-www/recipes/www.rb

link '/var/www' do
  to '/vagrant/www'
end

Running A Recipe

./Vagrantfile

Vagrant.configure(2) do |config|
  config.vm.box = "chef/centos-6.6"
  config.vm.network "forwarded_port", guest: 8080, host: 8080
  
  config.vm.provision "chef_solo" do |chef|
    chef.cookbooks_path = ["site-cookbooks", "cookbooks"]
    chef.run_list = ["recipe[animal-www::www]"]
  end
end

Running A Recipe (cont.)

Let's run Chef

$ vagrant provision
... Running provisioner: chef_solo...
...
... Run List is [recipe[animal-www::www]]
... Run List expands to [animal-www::www]
...
... link[/var/www] created

Running A Recipe (cont.)

Seeing if it worked

$ vagrant ssh
Last login: Tue Mar 17 14:39:00 2015 from 10.0.2.2
[vagrant@localhost ~]$ cat /var/www/index.html
...file contents...

The Plan

We want to serve the page in nginx
So we need to create an nginx config file
So we need to install nginx
So we need an nginx cookbook
So we need a way to pull in cookbooks

The Librarian

./Gemfile

source 'https://rubygems.org'

gem 'knife-solo'
gem 'librarian-chef'

The Librarian (cont.)

Install Librarian-Chef

$ chef exec bundle install --no-deployment
Fetching gem metadata...
...

The Librarian (cont.)

Create the Cheffile:

$ chef exec librarian-chef init
      create Cheffile

The Librarian (cont.)

./Cheffile

#!/usr/bin/env ruby
site 'https://supermarket.getchef.com/api/v1'

cookbook 'nginx'

The Librarian (cont.)

WINDOW ONLY — Set SSL_CERT_FILE

PS > [Environment]::SetEnvironmentVariable(
  "SSL_CERT_FILE",
  "C:\opscode\chefdk\embedded\ssl\certs\cacert.pem",
  "User")

The Librarian (cont.)

Install cookbook dependencies:

$ chef exec librarian-chef install
Installing apt (2.6.1)
Installing rsyslog (1.15.0)
[...]
Installing yum-epel (0.6.0)
Installing runit (1.5.18)
Installing nginx (2.7.4)

The Librarian (cont.)

./site-cookbooks/animal-www/metadata.rb

name             'animal-www'
maintainer       'YOUR_COMPANY_NAME'
maintainer_email 'YOUR_EMAIL'
license          'All rights reserved'
...
version          '0.1.0'

depends 'nginx'

Nginx Configuration

./site-cookbooks/animal-www/recipes/www.rb

[...cookbook_file stuff...]

include_recipe 'nginx'

template '/etc/nginx/sites-available/animals' do
  variables({
    :root => '/var/www',
    :port => 8080
  })
  notifies :reload, 'service[nginx]', :delayed
end

nginx_site 'animals' do
  enable true
end

Nginx Configuration (cont.)

./site-cookbooks/animal-wwww/templates/default/animals.erb

server {
  listen <%= @port %>;
  location / {
    root <%= @root %>;
    index index.html index.htm;
    sendfile off;
  }
}

Test It Out

$ vagrant provision
==> default: Running provisioner: chef_solo...
==> default: Detected Chef (latest) is already installed
Generating chef JSON and uploading...
==> default: Running chef-solo...
...

Then load http://localhost:8080/

Let's Make It Hit a REST Endpoint

Set Up Angular.js

First install Bower

$ sudo npm install -g bower
...
$ cd www
$ mkdir bower_components
$ bower install angular
...
$ cd ..

Set Up Angular.js (cont.)

./www/index.html

<!DOCTYPE html>
<html ng-app="animals">
<head>
  <title>Animals R Fun</title>
  <script type="text/javascript"
    src="bower_components/angular/angular.js"></script>
  <script type="text/javascript" src="main.js"></script>
</head>
<body ng-controller="AnimalsCtrl as ctrl">
  <p>Can I haz animals?</p>
  <ul><li>Aardvarks</li><li>Yeti Crab</li></ul>
  <p>More plz: {{ctrl.random}}</p>
</body>
</html>

Set Up Angular.js (cont.)

./www/main.js

angular.module('animals', [])
.controller('AnimalsCtrl', function ($http) {
  var self = this;
  $http.get('/api/random').success(function (data) {
    self.random = data;
  });
});

Set Up API

./site-cookbooks/animal-wwww/templates/default/animals.erb

server {
  listen <%= @port %>;
  location / {
    root <%= @root %>;
    index index.html index.htm;
    sendfile off;
  }
  location /api/ {
    proxy_pass http://localhost:3000/;
  }
}

Set Up API (cont.)

./api/app.js

var app = require('express')();
var as = ['Axolotl', 'Narwhal', 'Sloth'];
app.get('/random', function (req, res) {
  var r = Math.floor(Math.random()*100);
  res.send(as[r % as.length]);
});
app.listen(3000);

Set Up API (cont.)

Install Express from the host:

$ cd api
$ mkdir node_modules
$ npm install express
express@4.12.2 node_modules\express
...
$ cd ..

Set Up API (cont.)

./site-cookbooks/animal-www/recipes/api.rb

include_recipe 'nodejs'

link '/var/api' do
  to '/vagrant/api'
end

Set Up API (cont.)

./site-cookbooks/animal-www/metadata.rb

name             'animal-www'
maintainer       'YOUR_COMPANY_NAME'
maintainer_email 'YOUR_EMAIL'
license          'All rights reserved'
...
version          '0.1.0'

depends 'nginx'
depends 'nodejs'

Set Up API (cont.)

./Cheffile

#!/usr/bin/env ruby
site 'https://supermarket.getchef.com/api/v1'

cookbook 'nginx'
cookbook 'nodejs'

Set Up API (cont.)

Update cookbook dependencies:

$ chef exec librarian-chef install
[...]
Installing nginx (2.7.4)
Installing nodejs (2.2.0)

Set Up API (cont.)

./Vagrantfile

Vagrant.configure(2) do |config|
  config.vm.box = "chef/centos-6.6"
  config.vm.network "forwarded_port", guest: 8080, host: 8080
  
  config.vm.provision "chef_solo" do |chef|
    chef.cookbooks_path = ["site-cookbooks", "cookbooks"]
    chef.run_list = ["animal-www::api", "animal-www::www"]
  end
end

Set Up API (cont.)

Time to run Chef again

$ vagrant provision
... Running provisioner: chef_solo...
...
... Run List expands to [animal-www::www, animal-www::api]
...

Test The API

Start Express manually:

$ vagrant ssh
Last login: Tue Mar 17 21:33:51 2015 from 10.0.2.2
[vagrant@localhost ~]$ node /var/api/app.js

Then load http://localhost:8080/

Let's Run Express As a Service

Runit Service

Append to: ./site-cookbooks/animal-www/recipes/api.rb

# ...existing lines...

user 'api' do
  system true
  shell '/sbin/nologin'
end

include_recipe 'runit'
runit_service 'api' do
  default_logger true
  options({
    :user => 'api',
    :path => '/var/api/app.js'
  })
end

Runit Service (cont.)

./site-cookbooks/animal-www/templates/default/sv-api-run.erb

#!/bin/sh
exec 2>&1
exec chpst -u <%= @options[:user] %> \
  node "<%= @options[:path] %>"

Runit Service (cont.)

./site-cookbooks/animal-www/metadata.rb

name             'animal-www'
...
version          '0.1.0'

depends 'nginx'
depends 'nodejs'
depends 'runit'

Runit Service (cont.)

./Cheffile

#!/usr/bin/env ruby
site 'https://supermarket.getchef.com/api/v1'

cookbook 'nginx'
cookbook 'nodejs'
cookbook 'runit'

Runit Service (cont.)

Time to run Chef again

$ vagrant provision
... Running provisioner: chef_solo...
...
... user[api] created
...
... runit_service[api] enabled
...

Then load http://localhost:8080/

Refactoring Time

Default Recipe

./site-cookbooks/animal-www/recipes/default.rb

include_recipe 'animal-www::www'
include_recipe 'animal-www::api'

Default Recipe (cont.)

./Vagrantfile

Vagrant.configure(2) do |config|
  config.vm.box = "chef/centos-6.6"
  config.vm.network "forwarded_port", guest: 8080, host: 8080
  
  config.vm.provision "chef_solo" do |chef|
    chef.cookbooks_path = ["site-cookbooks", "cookbooks"]
    chef.run_list = ["animal-www"]
  end
end

Default Recipe (cont.)

Time to run Chef again

$ vagrant provision
... Running provisioner: chef_solo...
...
... Run List expands to [animal-www]
...

Attributes

./site-cookbooks/animal-www/recipes/api.rb

user 'api' do
  system true
  shell '/sbin/nologin'
end

runit_service 'api' do
  default_logger true
  options({
    :user => 'api',
    :path => '/var/api/app.js'
  })
end

Attributes (cont.)

./site-cookbooks/animal-www/attributes/default.rb

node.default['animal-www']['api']['user'] = 'api'

Attributes (cont.)

./site-cookbooks/animal-www/recipes/api.rb

user node['animal-www']['api']['user'] do
  system true
  shell '/sbin/nologin'
end

runit_service 'api' do
  default_logger true
  options({
    :user => node['animal-www']['api']['user'],
    :path => '/var/api/app.js'
  })
end

Attributes (cont.)

./Vagrantfile

Vagrant.configure(2) do |config|
  config.vm.box = "chef/centos-6.6"
  config.vm.network "forwarded_port", guest: 8080, host: 8080
  
  config.vm.provision "chef_solo" do |chef|
    chef.cookbooks_path = ["site-cookbooks", "cookbooks"]
    chef.run_list = ["animal-www"]
    chef.json = {
      "animal-www" => {
        "api" => { "user" => "derp" }
      }
    }
  end
end

Attributes (cont.)

Time to run Chef again

$ vagrant provision
... Running provisioner: chef_solo...
...
... user[derp] created
...

Attributes (cont.)

$ vagrant ssh
Last login: Wed Mar 18 19:45:42 2015 from 10.0.2.2
[vagrant@localhost ~]$ ps -eo user,pid,cmd | grep node
derp      8913 node /var/api/app.js
vagrant   8942 grep node

Foodcritic

Lint your cookbook:

$ foodcritic site-cookbooks/animal-www
FC008: Generated cookbook metadata needs updating...
FC008: Generated cookbook metadata needs updating...

What is FC008?

Now...

Go Forth And Chef

Topics Not Covered

Idempotency
LWRPs