Best and easy way to install puppet on SLES12

Based on the following question:

https://ask.puppetlabs.com/question/392/best-way-to-install-puppet-master-under-sles-suse-11-r2/

# zypper addrepo http://download.opensuse.org/repositories/systemsmanagement:/puppet/SLE_12/systemsmanagement:puppet.repo
# zypper refresh
# zypper install puppet

Run a custom fact based on core facts

So what if my previous example puppet custom fact easy as 1 2 3, needs to be run only on RedHat systems?

An additional line on the ruby file is added:

Facter.add('netuuid') do
   confine :operatingsystem => "RedHat"
   setcode do
      Facter::Core::Execution.exec("echo `grep UUID /etc/sysconfig/network-scripts/ifcfg-eth0 | cut -c 7-42`")
   end
end

Any core fact can be referenced with the colon and name of the fact
:operatingsystem
:osfamily
:kernel
etc.

Proper puppet variable declaration

The problem:

Error: Could not retrieve catalog from remote server: Error 400 on SERVER: Syntax error at ','; expected '}' 

Wrong variable declaration:

class repos::params {
      $baseurl = "foo",
      $baseurl_key = "ha",
      $sles12_baseurl = "doo",
      $sles12_SDK_baseurl = "ken",
}


Proper variable declaration:

class repos::params {
      $baseurl = "foo"
      $baseurl_key = "ha"
      $sles12_baseurl = "doo"
      $sles12_SDK_baseurl = "ken"
}

Enabling puppet syntax highlighting for vi

This works for Ubuntu and should be the same similar process for other distributions.

# apt-get install vim-puppet
# vim-addons -w install puppet (system wide configuration for all users)
# vim-addons install puppet (for the current user)

Read on:
/usr/share/doc/vim-puppet/README.Debian

SLES12 and puppet agent

I found close to no documentation on getting the puppet agent running on SLES 12.

What worked for me was the following repository and then only a zypper install puppet.

http://download.opensuse.org/repositories/systemsmanagement:/puppet/SLE_12/

That's pretty much it.

Puppet custom fact easy as 1, 2, 3.

After taking a careful reading at creating a custom fact. The solution was as follows to get the net uuid from /etc/sysconfig/network-scripts/ifcfg-eth0:

My custom fact stored on <modulepath>/<module>/lib/facter/netuuid.rb:

Facter.add('netuuid') do

        setcode do

                Facter::Core::Execution.exec("echo `grep UUID /etc/sysconfig/network-scripts/ifcfg-eth0 | cut -c 7-42`")

        end

end

I have created the <modulepath>/<module>/templates/netuuid.erb with this content:

<%= netuuid %>

And then call my custom netuuid facter variable on a template inside a manifest:

class netuuid {

        file { '/tmp/netuuid':

                        path    => '/tmp/netuuid',

                        ensure  => file,

                        content => template("module1/netuuid.erb"),

                }

}

# cat /tmp/netuuid

e9ca61ca-7fee-4ce6-9728-f9eacd343b08

References:
https://docs.puppetlabs.com/guides/templating.html
https://docs.puppetlabs.com/facter/2.4/custom_facts.html

Pending: create a custom fact to retrieve the network UUID

http://docs.puppetlabs.com/facter/latest/custom_facts.html

Maintain known_hosts file with a puppet class

Each time an ssh client gets connected to another ssh remote host, a known_hosts file is generated or updated based on the remote host public key.

The purpose of this file is well explaines on the following link: http://en.wikibooks.org/wiki/OpenSSH/Client_Configuration_Files#.7E.2F.ssh.2Fknown_hosts

Let's say that we have a network with 100 servers and each time we add another server to this network all the machines need to update the known_hosts file with the new public key. 

First step: ask the new machine for it's public key with ssh-keyscan:

# ssh-keyscan localhost/remotehost

# localhost SSH-2.0-OpenSSH_5.3

localhost ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAygRKDjzHw1a1L79f5rNaGlqPUDndZv9KhtZPG2MYrUrU/9NiBOiVDWwllUwWXQkLY3fhdTVncjGfzn4oc09876J3uXZJaNWr0PZpD8S7Y6+50iZWYVA0fTM0j32WdD3MMfJjCtrXo+/gDx9+XiQPXlWqkuy5L5PRIvjIzVeZwL6BDDalmQXx3Jw5QcfQn9Bc7m+Bw7ZO80mxnFnKH5zZa8jdjd6XPSLXN0Q+5UlvZ5o5hxaFA+4ywtvKbF6avlQj5rm9+6kGUkVLIZRVw+lkkGqSixsTMGC3mZURH2s38UB1OjHXQSW8DP/mImcAAQWB3V5JDHbswee99C8CU6ekcw==

And manually append the output to your ssh_known_hosts/known_hosts file in the proper format (man ssh-keyscan):

     Output format for rsa1 keys:

     host-or-namelist bits exponent modulus

     Output format for rsa and dsa keys:

     host-or-namelist keytype base64-encoded-key

     Where keytype is either “ssh-rsa” or “ssh-dss”.

Distribute this file with a puppet class on your nodes and you won't be prompted again to add this new key into your known_hosts/ssh_known_hosts file at the first login attempt. 

For sure this is far from perfect, but solves the problem in a short time. 

Puppet: estructura de un módulo y como invocar a sus clases

Dicen que es de sabios cambiar de opinión, pero también es de idiotas permanecer aferrados. Como sea, ahora que he estado aprendiendo algo de puppet, he tenido que generarme algunos módulos para hacer algunas tareas básicas de configuración en mis nodos. Para lo que es bueno recordar las siguientes referencias; basado en mi siguiente estructura de directorios:

# tree
.
└── base
    ├── files
    │   ├── hosts
    │   ├── motd
    │   └── vimrc
    ├── manifests
    │   ├── hosts.pp
    │   ├── init.pp
    │   ├── motd.pp
    │   └── vimrc.pp
    └── tests
        └── init.pp

4 directories, 8 files

Tendría que llamar a las clases de la siguiente manera:

# cat ../manifests/site.pp

node 'foo-host' {

        include base::hosts

}

node 'default' {

        include base::motd

        include base::vimrc

        include base::hosts

}