Placement of Variables in Puppet module

puppet

I've got a puppet module to setup several Gigaspaces PU's. Each of these have quite a few variables to be placed within the configuration file templates. We're also using several different environments so these variables are repeated several times to contain the values for each environment.

My question is where the best place to store these variables would be? A class of their own, an external .pp I import, or something other?

Best Answer

A lot of what you're asking comes down to convention more than strict language requirements... The language is flexible enough to do things a number of different ways.

If all the servers are being configured the same, it should work fine to have a single "gigaspace" class with the variables set at the top.

If your needs are more complicated than a single class of server, what I would do is create a "gigaspace" module with a common class holding variables inherited by classes needing the variables. In gigaspace/manifests there'd be an "init.pp" containing "class gigaspace {...}", and then a "common.pp" containing "class gigaspace::common {...}". Then in any class that I needed access to those variables, I would inherit from the common class, like "class gigaspace::master inherits gigaspace::common { ... }".

If you don't inherit from the other class, it's a pain to get at variables in another class, especially from within a template. With a straight include you can get read-only access via specifying the whole name, however.

Related Solutions

Puppet: Checking sets of variables

As @Zoredache mentioned, there is no loop in Puppet. But you can get around this by using a definition, something like this:

define show_ip {
    $inf = "ipaddress_${name}"
    $ip = inline_template('<%= scope.lookupvar(inf) %>')

    if $ip =~ /192\.168\.3.*/ {
        notify {"Found IP $ip": }
    }
}

$ifs = split($interfaces, ',')

show_ip { $ifs: }

Belows is the output when directly calling:

# puppet manifests/defines/net.pp 
warning: Implicit invocation of 'puppet apply' by passing files (or flags) directly
to 'puppet' is deprecated, and will be removed in the 2.8 series.  Please
invoke 'puppet apply' directly in the future.

notice: Found IP 192.168.3.118
notice: /Stage[main]//Show_ip[eth1]/Notify[Found IP 192.168.3.118]/message: defined 'message' as 'Found IP 192.168.3.118'
notice: Finished catalog run in 0.07 seconds

Source: https://blog.kumina.nl/tag/puppet-tips-and-tricks/

Ssh – How to use Puppet to maintain SSH host keys across system rebuilds

My problem is that this feels like mixing code and data (since all of the host keys live inside a module directory) and I have to make another commit to the Puppet VCS every time I add a new set of hosts. Is there a better way to manage these things?

You can adjust your fileserver.conf and basically share out another directory you use just for ssh config if you want to separate your puppet files from the SSH config/keys.

fileserver.conf
[sshconfig]
  path /srv/puppet/sshconfig/
  allow *

With a config like above your manifest could look like below, and files would be retrieved from /srv/puppet/sshconfig/$fqdn/.

file { "/etc/ssh/":
  source  => "puppet:///sshconfig/$fqdn",
  ...
}

Best Answer

Related Solutions

Puppet: Checking sets of variables

Ssh – How to use Puppet to maintain SSH host keys across system rebuilds

Related Topic