Jan 27, 2015
IT Automation with Chef
Anuchit [email protected]
Chef Server*hosted*
Node*chef-client*
Workstation*chef*
Git
Tools
● Chef client tools for admin workstation● Chef server● Node with bootstrap
Chef client
Install from http://www.getchef.com/chef/install/ choose match with your operating system and arch.
Chef client
* for Linux and Mac user can use shell script installer from curl :)
Chef server
You can use on premises chef server or use hosted chef. choose your version at http://www.getchef.com/chef/choose-your-version/
Chef server
Chef server
Starter kit
Download Starter Kit on Administration page, then extract to your home directory.
Starter kit
Git repository
Chef need repository for your cookbook. Change to your chef-repo and using git to init your repository.
git initgit add .git commit -m “add starter kit”
* Ref : Customized Git Configuration
Try knife
Change to your Chef repo directory and use knife command line eg: knife client list
knife client list
Node bootstrap
To add node to Chef server, use knife bootstrap to your node.knife bootstrap fqdn/ip --sudo -x username -P passwd -N "nodename"
knife bootstrap 192.168.2.138 --sudo -x username -P passwd -N "nodename"
Node bootstrap
Node bootstrap
Cookbook
Now write your first cookbook call apache, use knife to create new cookbook.
knife cookbook create apache
Cookbook : Apache
Edit cookbooks/apache/recipes/default.rb to create your recipe, with following structure
# install apache...
# start the apache service make sure the service starts...
# write our home page...
Cookbook : Apache# install apachepackage "apache2" do
action :installend
# start the apache service make sure the service startsservice "apache2" do
action [ :enable, :start]end
# write our home pagecookbook_file "/var/www/index.html" do
source "index.html"mode "0644"
end
Cookbook : Apache
At the last part in cookbook_file you must have index.html in cookbooks/apache/files/default/index.html write your own content.
<html> <title>Hello World from Chef</title><body> <h1>Hello World from Chef</h1></body></html>
Cookbook upload
Each part call resources, which are step to install apache, enable service and create default html file. Now you are ready to publish your cookbook.
knife cookbook upload apache
Cookbook
Ubuntu need you to update APT cache before install any package the you shuld create apt cookbook to update APT cache first
knife cookbook create apt
Cookbook : apt
Use the execute command to update APT cache
execute "apt-get update" docommand "apt-get update"
end
Cookbook upload
Now you are ready to publish your apt cookbook.
knife cookbook upload apt
Cookbook
Run list
After upload cookbook to Chef server, you must create a run list for the node to apply recipes.
Run list
Run list
Chef Client
Now back to your node, run command sudo chef-client to apply run list.
sudo chef-client
* Run remote by knife: knife ssh ‘name:*’ ‘sudo chef-client’ -x username -P password
Check the result
Open your browser and browse to your node with an ip address or fqdn.
Check the report
Goto Chef server to check your report; success, failure, aborted.
Reports
Reports
Make more dynamic
Your first recipe support only Ubuntu node, then make support another distributions you may add following items for more dynamically
● Attributes● Templates● Metadata
Attributes
Add cookbooks/apache/attributes/default.rb as a default values for your recipes.
case node["platform_family"]when "debian" default["package_name"] = "apache2" default["service_name"] = "apache2" default["document_root"] = "/var/www"when "rhel" default["package_name"] = "httpd" default["service_name"] = "httpd" default["document_root"] = "/var/www/html"end
Recipes# install apachepackage node["package_name"] do
action :installend
# start the apache service# make sure the service startsservice node["service_name"] do
action [ :enable, :start]end
# write our home pagetemplate "#{node["document_root"]}/index.html" do
source "index.html.erb"mode "0644"
end
Templates
Add template file for your index.html in cookbooks/apache/templates/default/index.html.erb
<html><title>Hello World</title><body>
<h1>Hello World from <%= node["fqdn"] %>!</h1></body></html>
Metadata
Edit metadata file in cookbooks/apache/metadata.rb
name 'apache'maintainer 'Anuchit Chalothorn'maintainer_email '[email protected]'license 'All rights reserved'description 'Installs/Configures apache'long_description IO.read(File.join(File.dirname(__FILE__), 'README.md'))version '0.1.0'
Rules
Roles allow you to encapsulate run lists and attribute required for a server to be. eg:
● Web Server● Database Server● etc
Rules
Create role for your web server by adding a webserver.rb in roles directory edit with following content.
name "webserver"description "Web Server"run_list "recipe[apache]"
default_attributes({"company" => "RedLineSoft"
})
Rules
Create role for your web server by adding a base-ubuntu.rb in roles directory edit with following content.
name "base-ubuntu"description "Base Ubuntu"run_list "recipe[apt]"
Rules
Update your cookbook version in metadata and add new role with following knife command
knife role create from file webserver.rb
knife role create from file base-ubuntu.rb
knife cookbook upload apache
Rules
Goto Chef server and add new roles to your node instead of using cookbook then use chef-client to apply recipes
Rules
Community Cookbook
Chef also have a community cookbooks. You can find an interest cookbook at http://community.opscode.com/cookbooks
Community Cookbook
Community Cookbook
You can use community cookbook from Chef community by using knife.
knife cookbook site download mysql 4.1.2
You'll get an archive file mysql-4.1.2.tar.gz in your chef-repo
* Easy way use; knife cookbook site install mysql
Using Community Cookbook
Now you get the archive cookbook from community already then extract an archive to cookbooks directory
tar zxvf mysql-4.1.2.tar.gz -C cookbooks/
Using Community Cookbook
Check dependency in metadata.rb, if you don’t have please download them, for homebrew, windows is dependency for OSX and Windows if you not use it, just comment it.
depends 'openssl', '~> 1.1'depends 'build-essential', '~> 1.4'
#depends 'homebrew'#depends 'windows'
Using Community Cookbook
Read the recipe files, mysql cookbook has mysql::client, mysql::server and mysql::ruby so you can specify which recipe you will use.
Using Community Cookbook
Download dependency cookbook for mysql
knife cookbook site download openssl 1.1.0knife cookbook site download build-essential 1.4.4tar zxvf openssl-1.1.0.tar.gz -C cookbooks/tar zxvf build-essential-1.4.4.tar.gz -C cookbooks/
knife cookbook upload build-essential openssl mysql
Using Community Cookbook
Create new role webserver-mysql to install webserver and mysql in this role.
name "webserver-mysql"description "Webserver and MySQL Database Server"run_list "recipe[apache]","recipe[mysql::client]","recipe[mysql::server]"
knife role from file webserver-mysql.rb
Using Community Cookbook
Goto Chef server add role to node then apply webserver-mysql role in node
Using Community Cookbook
Using Community Cookbook
Goto node and run chef-client to apply role.
sudo chef-client
Further Resources
● http://www.opscode.com● http://community.opscode.com● http://docs.opscode.com● http://learnchef.com● http://youtube.com/user/Opscode