What is Puppet
------------------------
Puppet is a configuration management system that allows you to define the
state of your IT infrastructure, then automatically enforces the correct state.


Basic Requirements
------------------------
Ruby 2.4 or later
Facter 3.10.0 or later
Hiera 5 or later [1]
The json gem (any modern version)

[1] Hiera isn’t separate from Puppet anymore
    Hiera began as an independent Ruby library that worked with Puppet.
    Over time, it became a requirement and was even included in the
    puppet-agent package, but it was limited by its original design.

    https://puppet.com/docs/puppet/4.10/hiera_intro.html

Simple Demo
------------------------
In this simple demo, we have a CA master server named 'master' and ip is 192.168.2.83
and an agent node named 'agent', ip is 192.168.2.30. 

On master server, file 'test.cfg' is under /etc/puppet/files/, puppet will sync this
file to /opt/ folder on agent node.

Step 1: Configure Puppet CA Master Server
1) create a puppet group and user
$ puppet resource group puppet ensure=presnt
$ puppet resource user puppet ensure=present gid=puppet shell='/sbin/nologin'

2) create the CA certificate and the puppet master certificate
$ puppet master --verbose --no-daemonize
(Once it says Notice: Starting Puppet master version <VERSION>, type ctrl-C to kill the process)

3) $ vi /etc/hosts
add new line:
192.168.2.30    agent

4) start puppet master
$ puppet master --verbose --no-daemonize &


Step 2: Config Puppet Agent Node
1) Edit puppet.conf
$ echo "[main]
server = master" >> /etc/puppet/puppet.conf

2) $ vi /etc/hosts
add new line:
192.168.2.83    master

3) Request certificates
$ puppet agent --test --ca_server=t2080qds -w 60
(Accept the request on master server by this command: puppet cert sign --all)


Step 3: Add site map on master
1) Edit /etc/puppet/fileserver.conf to make /etc/puppet/files available
$ mkdir /etc/puppet/files
$ touch /etc/puppet/files/test.cfg
$ vi /etc/puppet/fileserver.conf
add following lines:
[extra_files]
   path /etc/puppet/files
   allow *

2) Add a new sitemap
$ vi /etc/puppet/manifests/site.pp
add follwing lines:
file
{ "/opt/test.cfg":
source => "puppet:///extra_files/test.cfg",
}


Step 4: Run puppet on agent
$ puppet agent --test
$ ls /opt/ 
