Monday, January 27, 2014

User Management

Now, that we have seen what directory and file structure should be in puppet management. Lets, discuss about user management - creation of local user on client, which is a daily/frequent task of system admin.

Lets change directory to /etc/puppet/modules and create folder accounts with a sub-folder manifests i.e /etc/puppet/modules/accounts/manifests.

We will be creating two files init.pp and system.pp. Please be careful with directory and file names as they hold the key to run your configuration in an appropriate way.

Create and edit file - /etc/puppet/modules/accounts/manifests/system.pp


define accounts::system ($comment,$password) {
user { $title:
       ensure => 'present',
       shell => '/bin/bash',
       managehome => true,
     }
}


In the above file we have defined type accounts::system, which is done in order to ensure that every user should get home, shell as defined and not the default which is created by useradd utility. We also included variable for comment and password as these variables varies user to user and cannot be constant.

For example : If we try to create user on ubuntu via useradd utility manually, we will end up having /bin/sh as its shell until explicitly defined using -s option. 


Create and edit file - /etc/puppet/modules/accounts/manifests/init.pp


class accounts {
   
   @accounts::system { 'demo':
       comment      => 'demo users',
       password     => '*',
   }
}


Now that the defined type is done, we can use it to actually create the system user resources.We repeat as many times as necessary to create a system accounts::system resource for each user account you want to manage within Puppet.


Once we are done with these configuration, we just then have to realize it in nodes.

Edit file /etc/puppet/manifests/nodes/client2.pp

node 'client2.puppet.com' {
    include accounts
    realize (Accounts::System['demo'])
    }

Apply changes on the master to take effect.

On master server : CentOS


papply 
Notice: Compiled catalog for server.puppet.com in environment production in 0.05 seconds
Notice: Finished catalog run in 0.06 seconds


Let move on to client to fetch changes.

On client server : Ubuntu


pagent 
Info: Retrieving plugin
Info: Caching catalog for client2.puppet.com
Info: Applying configuration version '1390898484'
Notice: /Stage[main]/Accounts/Accounts::System[demo]/User[demo]/ensure: created
Notice: Finished catalog run in 0.67 seconds

Monday, January 20, 2014

Puppet Management

Lets, move one step ahead and clean up site.pp and follow a hierarchy in which resources should be setup, which is necessary, working with puppet.

/etc/puppet contains two important directories manifests and modules.


Puppet


.
|-- auth.conf
|-- fileserver.conf
|-- manifests
|   |-- nodes
|   |   |-- client1.pp
|   |   |-- client2.pp
|   |   `-- server.pp
|   `-- site.pp
|-- modules
|   |-- accounts
|   |   `-- manifests
|   |       |-- init.pp
|   |       `-- system.pp
|   |-- elinks
|   |   `-- manifests
|   |       `-- init.pp
|   |-- nmap
|   |   `-- manifests
|   |       `-- init.pp
|   `-- s3cmd
|       `-- manifests
|           `-- init.pp
`-- puppet.conf


Manifests


manifests
|   |-- nodes
|   |   |-- client1.pp
|   |   |-- client2.pp
|   |   `-- server.pp
|   `-- site.pp


Modules


modules
|   |-- accounts
|   |   `-- manifests
|   |       |-- init.pp
|   |       `-- system.pp
|   |-- elinks
|   |   `-- manifests
|   |       `-- init.pp
|   |-- nmap
|   |   `-- manifests
|   |       `-- init.pp
|   `-- s3cmd
|       `-- manifests
|           `-- init.pp

Edit file /etc/puppet/manifests/site.pp


import 'nodes/*.pp'

Create directory /etc/puppet/manifests/nodes and create files with respective node name prefix in the nodes directory, in our case

server.puppet.com - server.pp
client1.puppet.com - client1.pp
client2.puppet.com - client2.pp

Edit file /etc/puppet/manifests/nodes/server.pp

node 'server.puppet.com' {
    }

Edit file /etc/puppet/manifests/nodes/client1.pp


node 'client1.puppet.com' {
    }

Edit file /etc/puppet/manifests/nodes/client2.pp


node 'client2.puppet.com' {
    }


Now, lets create modules for the packages to be installed on the clients.
Remember, we used nmap in our previous post, lets take it again.

Change to directory /etc/puppet/modules

create directory with package name to be installed on clients, create a sub directory with name as manifests in the package directory.

Modules


|-- nmap
|   `-- manifests

Next, we will create a init.pp file. The puppet autoloader convention require all modules contain an init.pp file that contains a class or define that matches the module name.

Create and edit file /etc/puppet/modules/nmap/manifests/init.pp


class nmap {
case $operatingsystem {
        centos, redhat: {
        package { "nmap":
        ensure => installed,
        }
      }
        debian, ubuntu: {
        package { "nmap":
        ensure => installed,
        }
      }
     }
    }

Now, lets get back to main manifests directory having nodes and include package class.

Edit file /etc/puppet/manifests/nodes/client2.pp


node 'client2.puppet.com' {
    include nmap
    }

Before, applying changes lets create simple bash scripts for master and clients to apply and fetch changes respectively.

On master server : CentOS

Create and edit file - /usr/bin/papply


#!/bin/bash

/usr/bin/puppet apply -v  /etc/puppet/manifests/site.pp


On client server :Ubuntu

Create and edit file - /usr/bin/pagent


#!/bin/bash 

/usr/bin/puppet  agent -v --test


On master server : CentOS


papply 
Notice: Finished catalog run in 0.07 seconds


On client server :Ubuntu


pagent 
Info: Retrieving plugin
Info: Caching catalog for client2.puppet.com
Info: Applying configuration version '1390207277'
Notice: Finished catalog run in 0.41 seconds
                                       

Saturday, January 11, 2014

Basic Puppet Programs - Manifest

Basically, puppet programs are called “manifests,” and they use the .pp file extension.

site.pp: first file that the Puppet Master parses when determining a server’s catalog. It imports all the underlying subdirectories and the other special files in this directory. It also defines any global defaults, such as package managers as per http://projects.puppetlabs.com/projects/1/wiki/Puppet_Best_Practice2

To begin with, lets start definining things in the first file that the puppet master parses.

site.pp file should contain all the nodes -- clients as well as master, else it will not allow to proceed further.

On master server - CentOS

Create file - /etc/puppet/manifests/site.pp


node 'server.puppet.com' {
    }

node 'client1.puppet.com', 'client2.puppet.com' {
     }

Now, lets move further and introduce packages that we need to install on clients.

Now that we have clients on Ubuntu, we need to define operating system variable with a switch.


Packages to be installed - nmap and elinks.

Edit file /etc/puppet/manifests/site.pp


node 'server.puppet.com' {
    }

node 'client1.puppet.com', 'client2.puppet.com' {
      include nmap
      include elinks
    }

class nmap {
case $operatingsystem {
        centos, redhat: {
        package { "nmap":
        ensure => installed,
        }
      }
        debian, ubuntu: {
        package { "nmap":
        ensure => installed,
        }
      }
     }
    }

class elinks {
case $operatingsystem {
        centos, redhat: {
        package { "elinks":
        ensure => installed,
        }
      }
        debian, ubuntu: {
        package { "elinks":
        ensure => installed,
        }
      }
     }
    }

Note : If you can see in the above code in nodes section, we have included nmap and elinks class in clients and not in master. And in below section defined both the classes.

Apply changes on the master to take effect.


puppet apply -v  /etc/puppet/manifests/site.pp
info: Applying configuration version '1389452030'
notice: Finished catalog run in 2.43 seconds


Let move on to client to fetch changes.

On client server : Ubuntu


puppet agent -v --test
info: Caching catalog for client2.puppet.com
info: Applying configuration version '1389452959'
notice: /Stage[main]/Elinks/Package[elinks]/ensure: created
notice: /Stage[main]/Nmap/Package[nmap]/ensure: ensure changed 'purged' to 'present'
notice: Finished catalog run in 16.69 seconds


Note : Client synchronizes every 30 minutes for any changes/configuration applied on the puppet master server.


Friday, January 10, 2014

Puppet Configuration ( Setting up Master Server and Client Servers )

Setting up Master Puppet Server and Client Puppet Servers



Puppet as per dictionary means " a movable model of a person or animal that is typically moved either by strings controlled from above or by a hand inside it. "

To setup Puppet Master and Client, we would be taking an example, wherein our Master server will on CentOS and clients on Ubuntu

Master - server.puppet.com
Client 1 - client1.puppet.com 
Client 2 - client2.puppet.com

Configurations, that need to be set before installing any packages.

On master server : CentOS

Edit file /etc/sysconfig/network


HOSTNAME=server.puppet.com



service network restart
hostname server.puppet.com


Edit file /etc/hosts


127.0.0.1   server.puppet.com localhost.localdomain localhost
::1             localhost6.localdomain6 localhost6

192.168.1.28 server.puppet.com
192.168.1.10 client1.puppet.com
192.168.1.19 client2.puppet.com


On client server : Ubuntu

 Edit file /etc/hostname


client1.puppet.com



/etc/init.d/hostname restart
hostname client1.puppet.com




Edit file /etc/hosts


127.0.0.1       client1.puppet.com localhost

# The following lines are desirable for IPv6 capable hosts
::1     ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
192.168.1.10 client1.puppet.com
192.168.1.28 server.puppet.com


Now, lets move onto installing necessary packages on both the servers.

On master server : CentOS


yum install puppet-server
/etc/init.d/puppetmaster start

On client server : Ubuntu
  
apt-get install puppet
/etc/init.d/puppet start

telnet server.puppet.com 8140
Trying 192.168.1.28...
Connected to server.puppet.com.
Escape character is '^]'.
^]q

telnet> q
Connection closed.



Lets, move onto configuration, generating and signing of certificates.


On client server : Ubuntu

Configuration - Edit file  /etc/puppet/puppet.conf


In [main] section add the mentioned parameter


[main]
server=server.puppet.com


/etc/init.d/puppet restart


puppet agent  --waitforcert 60 --test
info: Caching certificate for ca
info: Creating a new SSL certificate request for client2.puppet.com
info: Certificate Request fingerprint (md5): 72:B7:5B:78:46:BF:DA:6A:8F:8C:CF:62:11:93:CD:F1


The above command will send a certificate signing request (csr) to master server, and as csr is delivered to master, we need execute commands on master server simultaneously after we see above info i.e.

info: Certificate Request fingerprint (md5): 72:B7:5B:78:46:BF:DA:6A:8F:8C:CF:62:11:93:CD:F1

The above client will not exit to terminal prompt until it receives an acknowledgement of the signed certificate by master server.

On master server : CentOS


puppetca --list
"client1.puppet.com" (72:B7:5B:78:46:BF:DA:6A:8F:8C:CF:62:11:93:CD:F1)


puppetca --sign client1.puppet.com
notice: Signed certificate request for client1.puppet.com
notice: Removing file Puppet::SSL::CertificateRequest client1.puppet.com at '/var/lib/puppet/ssl/ca/requests/client1.puppet.com.pem'


On client server : Ubuntu

As the certificate is signed from the master, complete output of previously executed commands on server will display info as,


puppet agent  --waitforcert 60 --test
info: Caching certificate for ca
info: Creating a new SSL certificate request for client2.puppet.com
info: Certificate Request fingerprint (md5): 72:B7:5B:78:46:BF:DA:6A:8F:8C:CF:62:11:93:CD:F1
info: Caching certificate for client2.puppet.com
info: Caching certificate_revocation_list for ca
info: Caching catalog for client2.puppet.com
info: Applying configuration version '1389337083'
info: Creating state file /var/lib/puppet/state/state.yaml
notice: Finished catalog run in 0.04 seconds