Let's start by creating an empty cookbook from inside the Chef repository cookbooks folder to install Apache2 using the chef command:

$ cd chef-repo/cookbooks
$ chef generate cookbook apache
Generating cookbook apache
[...]
Your cookbook is ready. Type `cd apache` to enter it.
[...]
If you'd prefer to dive right in, the default recipe can be found at:
recipes/default.rb

Now we need to tell Chef to install a package using the package resource.

Open that apache/recipes/default.rb file and type in the following:

package "httpd"

That's the most basic way we can tell Chef to install a package. This will do the install action by default. To be a little bit more comprehensive, we can use the full block to do the same:

package "httpd" do
  action :install
end

Still from inside the Chef repository, we now need to upload this new apache cookbook to the Chef server, so our servers can access it. To do this, we use the knife command on our workstation:

$ knife cookbook upload apache
Uploading apache         [0.1.0]
Uploaded 1 cookbook.

We just uploaded our first cookbook on the Chef server!

Let's confirm the cookbook is available remotely on the Chef server:

$ knife cookbook list
apache    0.1.0
starter   1.0.0

Now we have the apache cookbook remotely available, let's tell the Chef server that our particular node has to run it. Two options here are as follows:

Either way, we just told the Chef server to apply the apache cookbook on this particular server. Let's launch the Chef client on our remote node:

$ sudo chef-client
Starting Chef Client, version 12.15.19
resolving cookbooks for run list: ["apache"]
Synchronizing Cookbooks:
  - apache (0.1.0)
Installing Cookbook Gems:
Compiling Cookbooks...
Converging 1 resources
Recipe: apache::default
  * yum_package[httpd] action install
    - install version 2.4.6-40.el7.centos.4 of package httpd

Running handlers:
Running handlers complete
Chef Client finished, 1/1 resources updated in 32 seconds

Chef just installed the Apache HTTP server package for us! If we launch the Chef client, it won't install it again, as it knows it's already there (look at the largely different execution times):

$ sudo chef-client
[...]
Recipe: apache::default
  * yum_package[httpd] action install (up to date)
[...]
Chef Client finished, 0/1 resources updated in 04 seconds

Verify if the package is really installed:

$ which httpd
/usr/sbin/httpd
$ httpd -v
Server version: Apache/2.4.6 (CentOS)
Server built:   Jul 18 2016 15:30:14

Let's use our knowledge to create a MariaDB cookbook the same way we just deployed Apache, from the Chef repository:

$ chef generate cookbook cookbooks/mariadb

We want to install two packages: mariadb for the client and the libraries, and mariadb-server for the server. Add the following on the mariadb/recipes/default.rb file:

package "mariadb" do
  action :install
end

package "mariadb-server" do
  action :install
end

Alternatively, as we're writing plain Ruby, let's rewrite it in a more idiomatic way:

%w(mariadb mariadb-server).each do |name|
  package name do
    action :install
  end
end

Upload the cookbook from your workstation:

$ knife cookbook upload mariadb

Add the mariadb cookbook to the remote node's run list from your workstation:

$ knife node run_list add <nodename> mariadb

Run the Chef client on the remote host:

$ sudo chef-client
Starting Chef Client, version 12.15.19
resolving cookbooks for run list: ["apache", "mariadb"]
Synchronizing Cookbooks:
  - apache (0.1.0)
  - mariadb (0.1.0)
[...]
Recipe: mariadb::default
  * yum_package[mariadb] action install
    - install version 5.5.50-1.el7_2 of package mariadb
  * yum_package[mariadb-server] action install
    - install version 5.5.50-1.el7_2 of package mariadb-server
[...]
Chef Client finished, 2/3 resources updated in 25 seconds

Verify that the MariaDB package is correctly installed:

$ which mysql
/usr/bin/mysql
$ mysql --version
mysql  Ver 15.1 Distrib 5.5.50-MariaDB, for Linux (x86_64) using readline 5.1

Let's reuse our knowledge to create a cookbook that will install the packages needed for PHP support:

$ chef generate cookbook cookbooks/php

Let's add our Chef code that will install the following three packages: the php, php-cli, and php-mysql packages (respectively for PHP support, command line, and PHP/MySQL support) in the cookbooks/php/recipes/default.rb file:

%w(php php-mysql).each do |name|
  package name do
    action :install
  end
end

Upload this new php cookbook from your workstation:

$ knife cookbook upload php

Add the php cookbook to the remote node's run list from your workstation:

$ knife node run_list add vagrant php

Run the Chef client on the remote node:

$ sudo chef-client
$ php --version
PHP 5.4.16 (cli) (built: Aug 11 2016 21:24:59)

We now know the very basics of deploying cookbooks and installing packages on a remote node, using Chef!