|
I would like to write functions in the puppet language that accept a block of code, so that I can write my own iterators and other functions that accept code, without the context switch of doing it in ruby.
The specific use case I have is that we often need to run some piece of puppet code once among a group of nodes. To do that, we do a puppetdbquery to find similarly-classified nodes, then sort that list and see if the current node's certname is the first one on the list. If true, run some bit of code.
I would like to write a function like:
function runonce() {
|
$pdb_leader = join([
|
"group='${::group}'",
|
"stage='${::stage}'",
|
"function='${::function}'",
|
"whereami='${::whereami}'",
|
], ' and ').query_nodes('certname').sort[0]
|
|
if $::certname == $pdb_leader {
|
yield()
|
}
|
}
|
The way I might use this would be if I want to schedule a cron job to run on one of several identical web application servers:
runonce() {
|
cron {'a job':
|
# blah blah blah
|
}
|
}
|
ping Henrik Lindberg because I think we've talked about this before
|
