Puppet: Generate a unique integer id base on the hostname

uniqueid.pp

#
# Generate a unique integer id base on the hostname
# It works by stripping $domain from the $::fqdn,
# removing all characters except alphanumeric and converting to base 10
# $domain is provided if you have complex domains like *.hosting.example.com
#
class uniqueid (
    $domain = $::domain,
) {
    $node_id = inline_template("<%= '$::fqdn'.gsub('$domain','').gsub(/[^a-z0-9]/i,'').to_i(36) %>")
}

Nice code, I've used it myself. Two things I noticed. You use //i (case insensitive match). So there is a possibility that capital letters might appear (but this is a minor issue with fqdn). I would recommend '$::fqdn'..(...).downcase.gsub(...) instead.

Second issue I ran into was that I needed to modulus to get 32-bit integers. It may be tempting to use %232 or 231. DO NOT DO THIS :) I have run into many instances where host1.example.com and host2.example.com have the same remainder. Use a large prime Mersenne like 2**31-1 instead. :)

Exactly what I was looking for.

Excellent !

Thank you for this inline_template ! I wanted to use a integer derivated from a node node in order to "modulo" it, in order to use different puppetmaster, spreading the load of pupetmasters depending on ::fqdn.

Perfect !

for server_id in MySQL, used extra modulo % operator on top, giving range from 0 to 255

    $_server_id = Integer(inline_template("<%= '$::fqdn'.gsub('$::domain','').gsub(/[^a-z0-9]/i,'').to_i(36) % 256 %>"))