Understanding Chef Cookbooks

Once that we configure the chef server , let write a simple cookbook and see how it is executed. Run the commands in color to create a sample cookbook

[root@manja17-I14020 .chef]# cd ~/chef-repo/cookbooks/

[root@manja17-I14020 cookbooks]# chef generate cookbook httpd

Generating cookbook httpd

- Ensuring correct cookbook file content

- Ensuring delivery configuration

- Ensuring correct delivery build cookbook content

Your cookbook is ready. Type `cd httpd` to enter it.

There are several commands you can run to get started locally developing and testing your cookbook.

Type `delivery local --help` to see a full list.

Why not start by writing a test? Tests for the default recipe are stored at:

test/recipes/default_test.rb

If you'd prefer to dive right in, the default recipe can be found at:

recipes/default.rb

[root@manja17-I14020 cookbooks]# cd httpd/

[root@manja17-I14020 httpd]# ll

total 16

-rw-r--r--. 1 root root   47 Sep  3 05:47 Berksfile

-rw-r--r--. 1 root root 1133 Sep  3 05:47 chefignore

-rw-r--r--. 1 root root  568 Sep  3 05:47 metadata.rb

-rw-r--r--. 1 root root   53 Sep  3 05:47 README.md

drwxr-xr-x. 2 root root   24 Sep  3 05:47 recipes

drwxr-xr-x. 3 root root   40 Sep  3 05:47 spec

drwxr-xr-x. 3 root root   21 Sep  3 05:47 test

Add the code to the default.rb file

Go to "~/chef-repo/cookbooks/httpd/recipes" and add the below content as,

[root@chefdk recipes]# cat default.rb

#

# Cookbook Name:: httpd

# Recipe:: default

#

# Copyright (c) 2018 The Authors, All Rights Reserved.

package 'httpd' do

  action :install

end

service 'httpd' do

  action [ :enable, :start ]

end

cookbook_file "/var/www/html/index.html" do

  source "index.html"

  mode "0644"

end

Also create a file “index.html” in the httpd/files location. This will the same file that we will copy to the chef-nodes for httpd server. This is the home page for the httpd server.

Once that we have written the code, upload the cookbook to the chef server using,

[root@manja17-I14020 recipes]# knife cookbook upload httpd

Uploading httpd        [0.1.0]

Uploaded 1 cookbook.

Check the available  cookbooks in server using,

[root@manja17-I14020 recipes]# knife cookbook list

httpd   0.1.0

Now add the cookbook to the run_list using,

[root@manja17-I14020 recipes]# knife node run_list add firstnode httpd

firstnode:

  run_list: recipe[httpd]

Run lists define what cookbooks a node will use. The run list is an ordered list of all cookbooks and recipes that the chef-client needs to pull from the Chef server to run on a node. Run lists are also used to define roles, which are used to define patterns and attributes across nodes.

Run the Cook Book Manually on the chef-node using,

 [root@manja17-I14022 ~]# chef-client -r recipe[httpd]

[2018-09-03T06:19:54-04:00] INFO: Forking chef instance to converge...

Starting Chef Client, version 12.22.5

[2018-09-03T06:19:54-04:00] INFO: *** Chef 12.22.5 ***

[2018-09-03T06:19:54-04:00] INFO: Platform: x86_64-linux

[2018-09-03T06:19:54-04:00] INFO: Chef-client pid: 29567

[2018-09-03T06:19:54-04:00] INFO: The plugin path /etc/chef/ohai/plugins does not exist. Skipping...

[2018-09-03T06:19:57-04:00] INFO: Setting the run_list to [#<Chef::RunList::RunListItem:0x0000000001d9ac50 @version=nil, @type=:recipe, @name="httpd">] from CLI options

[2018-09-03T06:19:57-04:00] INFO: Run List is [recipe[httpd]]

[2018-09-03T06:19:57-04:00] INFO: Run List expands to [httpd]

[2018-09-03T06:19:57-04:00] INFO: Starting Chef Run for firstnode

[2018-09-03T06:19:57-04:00] INFO: Running start handlers

[2018-09-03T06:19:57-04:00] INFO: Start handlers complete.

[2018-09-03T06:19:57-04:00] INFO: HTTP Request Returned 404 Not Found:

[2018-09-03T06:19:57-04:00] INFO: HTTP Request Returned 404 Not Found:

[2018-09-03T06:19:57-04:00] INFO: Error while reporting run start to Data Collector. URL: https://chefserver.nova.com/organizations/nova/data-collector Exception: 404 -- 404 "Not Found"  (This is normal if you do not have Chef Automate)

resolving cookbooks for run list: ["httpd"]

[2018-09-03T06:19:57-04:00] INFO: Loading cookbooks [httpd@0.1.0]

Synchronizing Cookbooks:

[2018-09-03T06:19:57-04:00] INFO: Storing updated cookbooks/httpd/files/index.html in the cache.

  - httpd (0.1.0)

Installing Cookbook Gems:

Compiling Cookbooks...

[2018-09-03T06:19:57-04:00] INFO: HTTP Request Returned 404 Not Found:

Converging 3 resources

Recipe: httpd::default

  * yum_package[httpd] action install[2018-09-03T06:19:57-04:00] INFO: Processing yum_package[httpd] action install (httpd::default line 7)

 (up to date)

  * service[httpd] action enable[2018-09-03T06:19:59-04:00] INFO: Processing service[httpd] action enable (httpd::default line 11)

 (up to date)

  * service[httpd] action start[2018-09-03T06:19:59-04:00] INFO: Processing service[httpd] action start (httpd::default line 11)

 (up to date)

  * cookbook_file[/var/www/html/index.html] action create[2018-09-03T06:19:59-04:00] INFO: Processing cookbook_file[/var/www/html/index.html] action create (httpd::default line 15)

[2018-09-03T06:19:59-04:00] INFO: cookbook_file[/var/www/html/index.html] created file /var/www/html/index.html

    - create new file /var/www/html/index.html[2018-09-03T06:19:59-04:00] INFO: cookbook_file[/var/www/html/index.html] updated file contents /var/www/html/index.html

    - update content in file /var/www/html/index.html from none to e3b0c4

    (no diff)[2018-09-03T06:19:59-04:00] INFO: cookbook_file[/var/www/html/index.html] mode changed to 644

    - change mode from '' to '0644'

    - restore selinux security context

[2018-09-03T06:20:00-04:00] INFO: Chef Run complete in 2.342676017 seconds

Running handlers:

[2018-09-03T06:20:00-04:00] INFO: Running report handlers

Running handlers complete

[2018-09-03T06:20:00-04:00] INFO: Report handlers complete

Chef Client finished, 1/4 resources updated in 05 seconds

This is how we will be writing a simple cookbook and automate them on the chef-nodes.