Practical hands on Puppet

=========== Puppet practice on Centos ===========
[root@puppetmaster modules]$  cd /etc/puppetlabs/code/environments/production/manifests/
[root@puppetmaster manifests]$  ls
[root@puppetmaster manifests]$  vi hello.pp
[root@puppetmaster manifests]$  cat hello.pp
notify {'Hello World':}
[root@puppetmaster manifests]$
================================================================================================
** If want to apply above on puppet server then use following command on puppet server

[root@puppetmaster manifests]$  puppet apply hello.pp
Notice: Compiled catalog for puppetmaster.localdomain in environment production in 0.02 seconds
Notice: Hello World
Notice: /Stage[main]/Main/Notify[Hello World]/message: defined 'message' as 'Hello World'
Notice: Applied catalog in 0.01 seconds

** If want to apply on puppet client to client then use following command on puppet server

[root@webprd1 ~]$  puppet agent -t
Info: Using configured environment 'production'
Info: Retrieving pluginfacts
Info: Retrieving plugin
Info: Retrieving locales
Info: Caching catalog for webprd1.localdomain
Info: Applying configuration version '1538057264'
Notice: Hello World
Notice: /Stage[main]/Main/Notify[Hello World]/message: defined 'message' as 'Hello World'
Notice: Applied catalog in 0.03 seconds
[root@webprd1 ~]$

********* now we are using file resource type *********

[root@puppetmaster manifests]$  vi demo.pp
[root@puppetmaster manifests]$  cat demo.pp
file {'/tmp/demo.txt':
        ensure => present,
        content => 'Hello linuxchamps users',
        }


[root@webprd1 ~]$  puppet agent -t --noop    <----------------if you want to check what are new changes going to apply on client use noop this is dry run
Info: Using configured environment 'production'
Info: Retrieving pluginfacts
Info: Retrieving plugin
Info: Retrieving locales
Info: Applying configuration version '1538057956'
Notice: /Stage[main]/Main/File[/tmp/demo.txt]/ensure: current_value 'absent', should be 'present' (noop)    <------ its saying /tmp/demo.txt is absent should be present
Notice: /Stage[main]/Main/Notify[Hello World]/message: current_value 'absent', should be 'Hello World' (noop)
Notice: Class[Main]: Would have triggered 'refresh' from 2 events
Notice: Stage[main]: Would have triggered 'refresh' from 1 event
Notice: Applied catalog in 0.02 seconds
[root@webprd1 ~]$

[root@webprd1 ~]$  ll /tmp/demo.txt
ls: cannot access /tmp/demo.txt: No such file or directory  <------- Currenlty file is not present

[root@webprd1 ~]$  puppet agent -t
Info: Using configured environment 'production'
Info: Retrieving pluginfacts
Info: Retrieving plugin
Info: Retrieving locales
Info: Caching catalog for webprd1.localdomain
Info: Applying configuration version '1538058210'
Notice: /Stage[main]/Main/File[/tmp/demo.txt]/ensure: defined content as '{md5}18a8acba178a037b8f1895c04eaf7387' <--- file is created
Notice: Hello World
Notice: /Stage[main]/Main/Notify[Hello World]/message: defined 'message' as 'Hello World'
Notice: Applied catalog in 0.11 seconds
[root@webprd1 ~]$
[root@webprd1 ~]$  cat /tmp/demo.txt   <------------ file is present at client side
Hello linuxchamps users                            

========== Now lets try to change file permissons ========

[root@puppetmaster manifests]$  cat demo.pp
file {'/tmp/demo.txt':
        ensure => present,
        content => 'Hello linuxchamps users',
        mode    => '774'
        }

[root@webprd1 ~]$  ll /tmp/demo.txt <-------- current permissons for /tmp/demo.txt
-rw-r--r--. 1 root root 23 Sep 27 19:53 /tmp/demo.txt

       
[root@webprd1 ~]$  puppet agent -t
Info: Using configured environment 'production'
Info: Retrieving pluginfacts
Info: Retrieving plugin
Info: Retrieving locales
Info: Caching catalog for webprd1.localdomain
Info: Applying configuration version '1538058581'
Notice: /Stage[main]/Main/File[/tmp/demo.txt]/mode: mode changed '0644' to '0774'  <------- File permissons has been changed from 644 to 774
Notice: Hello World
Notice: /Stage[main]/Main/Notify[Hello World]/message: defined 'message' as 'Hello World'
Notice: Applied catalog in 0.02 seconds
[root@webprd1 ~]$

[root@webprd1 ~]$  ll /tmp/demo.txt
-rwxrwxr--. 1 root root 23 Sep 27 19:53 /tmp/demo.txt
[root@webprd1 ~]$

======== Lets see user creation via puppet =======

[root@puppetmaster manifests]$  cat user.pp 
user { 'anuj':
       ensure           => 'present',
       gid              => '501',
       home             => '/home/anuj',
       password         => '!!',
       password_max_age => '99999',
       password_min_age => '0',
       shell            => '/bin/bash',
       uid              => '501',
     }
group { 'appuser':
                gid  =>  '501',
  }

file { "/home/anuj":
    ensure            =>  directory,
    owner             =>  anuj,
    group             =>  appuser,
    mode              =>  '0750'
}


   
[root@webprd1 ~]$  grep -i anuj /etc/passwd <-------- on Puppet agent user anuj is not present
[root@webprd1 ~]$

[root@webprd1 home]$  grep -i appuser /etc/group


[root@webprd1 home]$  puppet agent -t
Info: Using configured environment 'production'
Info: Retrieving pluginfacts
Info: Retrieving plugin
Info: Retrieving locales
Info: Caching catalog for webprd1.localdomain
Info: Applying configuration version '1538064313'
Notice: Hello World
Notice: /Stage[main]/Main/Notify[Hello World]/message: defined 'message' as 'Hello World'
Notice: /Stage[main]/Main/Group[appuser]/ensure: created    <--------------- group appuser created
Notice: /Stage[main]/Main/User[anuj]/ensure: created        <--------------- user anuj created
Notice: /Stage[main]/Main/File[/home/anuj]/ensure: created    <--------------- home directory created for user anuj
Notice: Applied catalog in 0.19 seconds
[root@webprd1 home]$


[root@webprd1 home]$  grep -i anuj /etc/passwd
anuj:x:501:501::/home/anuj:/bin/bash
[root@webprd1 home]$
[root@webprd1 home]$  grep -i appuser /etc/group
appuser:x:501:
[root@webprd1 home]$  su - anuj
-bash-4.2$

================= lets try to install package via puppet on client ==============

[root@puppetmaster manifests]$  vi /etc/puppetlabs/code/environments/production/manifests/package.pp
package {'httpd':
        ensure  => present,
        name    => 'httpd'
        }
        service {'httpd':
                ensure  => running,
                enable    => true,
        }

*** have a look httpd package is not present on client at this mommnet  <==========

[root@webprd1 puppet]$  yum list httpd
Loaded plugins: fastestmirror, langpacks
Loading mirror speeds from cached hostfile
 * base: mirror.nbrc.ac.in
 * epel: mirror1.ku.ac.th
 * extras: mirrors.fibergrid.in
 * updates: mirrors.fibergrid.in
Available Packages
httpd.x86_64                                                2.4.6-80.el7.centos.1                                                updates


[root@webprd1 puppet]$  puppet agent -t
Info: Using configured environment 'production'
Info: Retrieving pluginfacts
Info: Retrieving plugin
Info: Retrieving locales
Info: Caching catalog for webprd1.localdomain
Info: Applying configuration version '1538096426'
Notice: Hello World
Notice: /Stage[main]/Main/Notify[Hello World]/message: defined 'message' as 'Hello World'
Notice: /Stage[main]/Main/Package[httpd]/ensure: created                        <======================== httpd package has been installed
Notice: /Stage[main]/Main/Service[httpd]/ensure: ensure changed 'stopped' to 'running' <================= httpd service has been started
Notice: /Stage[main]/Main/Service[httpd]/enable: enable changed 'false' to 'true'        <================ httpd service has been added at startup
Info: /Stage[main]/Main/Service[httpd]: Unscheduling refresh on Service[httpd]
Notice: Applied catalog in 84.98 seconds


[root@webprd1 ~]$  ps -ef | grep -i yum
root     15177 15089 10 06:30 ?        00:00:09 /usr/bin/python /usr/bin/yum -d 0 -e 0 -y install httpd  <=========== backend it call yum to install httpd
root     15345 15211  0 06:31 pts/3    00:00:00 grep --color=auto -i yum
[root@webprd1 ~]$
[root@webprd1 ~]$
[root@webprd1 ~]$  ps -ef | grep -i yum
root     15391 15211  0 06:31 pts/3    00:00:00 grep --color=auto -i yum