Puppet Administration [In progress]

Here we will try to create a module[sudo] and see how we can use it. For more information about the structure of a module you can check this link . Our mission is to add users sunny and bbee to the sudoers file. Firstly create a directory called sudo in /etc/puppet/modules/ directory. This is basically your module name. [root@puppet modules]# mkdir sudo Now create three sub-directories in it as manifests, files, templates. [root@puppet modules]# mkdir manifests files templates So your current structure is somewhat like this: sudo/ ├── files ├── manifests └── templates 3 directories, 0 files The first and foremost part is to check and install[If not installed] the necessary package. package { 'sudo':                 ensure => present,                 } The above code states that package sudo should be installed in ...

Puppet can be used as a standalone model or as agent/server model. There are basically 2 types of puppet version available in market. Free version of puppet. Enterprise version of puppet which is also know as puppet-enterprise. Here we will be installing the free version of puppet. 0. Enable EPEL repo, you can find the latest version of EPEL on below URL: https://fedoraproject.org/wiki/EPEL 1. Install prerequisites before installing puppet [root@rhel6 ~]# yum install ruby-shadow ruby ruby-libs 2. Resolve the dependencies like ruby(selinux). 3. Install puppetmaster and facter on the server node. [root@rhel6 ~]# yum install puppet-server facter 4. Install puppet and facter on the agent node. [root@rhel6 ~]# yum install puppet facter Once these packages are installed on both the machines. Make sure that your agent node can ping the server node with the name as puppet. [root@rhel6 ~]# ping puppet PING puppet (192.168.122.14) 56(84) bytes of data. 64 bytes fr...

Facter is a utility which collects and displays facts about the system such as operatingsystem, ip, MAC address, machine's hardware information. Point to note: If no specific facts are specifically asked for, then all facts will be returned. We can add our custom facts too. [root@rhel6 ~]# facter architecture => x86_64 augeasversion => 0.9.0 domain => sunny.com facterversion => 1.6.18 fqdn => rhel6.sunny.com hardwareisa => x86_64 hardwaremodel => x86_64 hostname => rhel6 id => root interfaces => eth1,lo ipaddress => 192.168.122.173 ipaddress_eth1 => 192.168.122.173 ipaddress_lo => 127.0.0.1 ............ ............ [root@rhel6 ~]# Now suppose you just need to see the hostname via facter command. [root@rhel6 ~]# facter hostname rhel6 [root@rhel6 ~]# It works well with grep command too. [root@rhel6 ~]# facter | grep memory memoryfree => 188.36 MB memorysize => 280.95 MB memorytotal => 280.95 MB [root@rhel6 ~]# The ...

*Modules in puppet* Modules are a way of arranging manifests/files/templates in puppet. Why they are arranged like this?? So that they can be automatically called by the puppet master when needed. What is the location of module?? Default location, you can find it by firing below command: [root@puppet modules]# puppet master --genconfig | grep modulepath     modulepath = /etc/puppet/modules:/usr/share/puppet/modules [root@puppet modules]# User defined location, If in-case you want to use the user defined location to fetch the modules so that puppet master can use it you need to use a option called --modulepath while firing the command. [root@puppet manifests]# puppet apply site.pp --modulepath=/tmp/mods/ notice: Finished catalog run in 0.26 seconds [root@puppet manifests]# Structure of a module: modules/ └── ntp     ├── files     │   ├── ntp.conf.debian     │   └── ntp.conf.el     ├──...

*Master daemon in Puppet "puppet master"* Puppet master is the central puppet server. Firing this command "puppet master" starts an instance of puppet master and runs as a daemon by default. [root@puppet ~]# /etc/init.d/puppetmaster status puppetmasterd is stopped [root@puppet ~]# puppet master [root@puppet ~]# /etc/init.d/puppetmaster status puppetmasterd (pid  31281) is running... [root@puppet ~]# If you want to enable full debugging mode while executing puppet master you can use the option --debug while firing it. [root@puppet ~]# puppet master --debug --no-daemonize debug: Puppet::Type::User::ProviderPw: file pw does not exist debug: Puppet::Type::User::ProviderUser_role_add: file roleadd does not exist debug: Puppet::Type::User::ProviderLdap: true value when expecting false debug: Puppet::Type::User::ProviderDirectoryservice: file /usr/bin/dscl does not exist debug: Failed to load library 'rubygems' for feature 'rubygems' debug: /File[/...

If you revoked or deleted the puppet agent’s certificate accidentally. Basically it is nearly impossible un-revoke a certificate. The solution is to recover all revoked certificates then revoke other certificates which don’t need to be recovered. But if in-case you have thousands of revoked certificates then its a bit lengthy process. Second one is to generate a new certificate for the client/agent and get that signed by the puppet master.  List of all the certificates which are signed at the moment:  [root@puppet requests]# puppet cert list --all + "fedora20"            (AE:57:40:F6:FC:E1:CD:DD:ED:EE:1E:8C:A7:81:0D:76) + "kubuntu14.sunny.com" (20:6B:A1:E2:A3:DE:B1:95:C8:80:4C:B4:27:2B:C0:A2) + "puppet.sunny.com"    (68:12:76:3C:D0:F8:0D:2D:8B:2B:40:E7:49:2D:55:5B) (alt names: "DNS:puppet", "DNS:puppet.sunny.com") + "rhel6.sunny.com"     (DC:6E:B1:FC:27:1D:7A:2A:85:E7:3E:3A:2...

*Agent sub-command in Puppet "puppet agent"* The puppet agent subcommand is a powerful tool which fetches the configurations from a master server and get that applied to the agent node. It has basically two modes: 1. Daemonize and fetch configurations every half-hour (this is by default and can be changed). 2. Run once and quit It is the main puppet client. Basically its purpose is to retrieve the local machine's configuration from a remote server[the master] and apply it to the agent node. In order to successfully communicate with the remote server, the client must have a certificate signed by a certificate authority provided by the puppet master. The client will connect and request a signed certificate unless and until the puppet master sign's the certificate the agent node cannot communicate with the puppet master. Once the client has a signed certificate, it will retrieve its configuration from the puppet master and apply it on the agent node. Now sup...

*Describe sub-command in Puppet "puppet describe" * The puppet describe sub-command can list info about the currently installed resource types on a given machine. This is a built in documentation and a great source of information. It helps us to know the behavior of types, their properties and parameters. "puppet describe -l" — List all of the resource types available on the system. "puppet describe -s <TYPE>" Print short information about a type, without describing every attribute "puppet describe <TYPE>" Shows each and every information about the type which you are referring too. [root@puppet ~]# puppet describe -l These are the types known to puppet: augeas          -  Apply a change or an array of changes to the ... computer        - Computer object management using DirectorySer ... cron            -  Installs a...

*Apply sub-command in Puppet "puppet apply"* This is the standalone puppet execution tool which is used to apply individual manifests. It is an application that complies and manages configuration on node. Point to note is puppet apply never runs as a daemon like puppet agent. It always runs like a single process which complies a catalog then applies it send a report that's it. Most important option with puppet apply command is modulepath. Suppose you are firing puppet apply XYZ.pp file then it will take the module location as /etc/puppet/modules by default but if in case your modules are there in some other directory suppose /root/puppet-modules then you can use "modulepath" with this location to ask puppet to use it. Running a puppet apply command to apply the changes to the machine with site.pp manifest. [root@puppet manifests]# puppet apply site.pp notice: /Stage[main]/Sudo/File[/etc/sudoers]/content: content changed '{md5}e81452ad78198a...

*Resources in Puppet "puppet resource"* Understanding Resources is fundamental to understanding how Puppet works. Resources are like building blocks. They can be combined to model the expected state of the systems you manage.  For more information about the resources in puppet you can fire "puppet resource -h" on CLI. This command transforms the current system state into puppet code also it has the ability to modify the current state of the system. Syntax: resource_type { 'resource_name'   attribute => value   ... } Below are the few examples: To see all the users in the machine. [root@puppet ~]# puppet resource user  To see a particular user in the machine.   [root@puppet ~]# puppet resource user sunny user { 'sunny':   ensure           => 'present',   comment          => 'Sunny_B',   gid     ...