String substitution in Puppet?

Question

Is it possible to do a string substitution/transformation in Puppet using a regular expression?

If $hostname is "web1", I want $hostname_without_number to be "web". The following isn't valid Puppet syntax, but I think I need something like this:

$hostname_without_number = $hostname.gsub(/\d+$/, '')

score 42 · Accepted Answer · answered May 03 '12 at 18:11

42

Yes, it is possible.

There's a regular expression substitution function built in. It probably calls the same underlying gsub function.

$hostname_without_number = regsubst($hostname, '\d+$', '')

Or if you prefer to actually call out to Ruby, you can use an inline ERB template:

$hostname_without_number = inline_template('<%= hostname.gsub(/\d+$/, "") %>')

answered May 03 '12 at 18:11

freiheit

1

Thanks! I'll use the built-in regsubst() this time, but I'm very glad to know about inline_template as well! That's very flexible. – richardkmiller May 05 '12 at 17:12
1

It's worth pointing out that `regsubst()` also supports a flags arg in the 4th position. A flag such as 'G' will globally replace all matches in the provided string. – killthrush Aug 18 '16 at 14:15
Providing Puppet v6 version of the link https://puppet.com/docs/puppet/6/function.html – Ceddaerrix Oct 22 '21 at 06:35

score 2 · Answer 2 · edited Dec 06 '18 at 19:18

2

In this page:

it is quite well explained and there is a fantastic trick for testing your regular expressions with irb.

Whith this link and the answer of freiheit I could resolve my problem with substitution of '\' for '/'.

$programfiles_sinbackslash = regsubst($env_programfiles,'\','/','G')

edited Dec 06 '18 at 19:18

IAmAliYousefi

answered Jul 11 '13 at 07:41

user45949

2 Answers2