puppet adding array elements in a loop

Question

I want something like this:

$ssl_domains = ['dev.mydomain.com']

['admin', 'api', 'web'].each |$site| {
  ['tom', 'jeff', 'harry'].each |$developer| {
    $ssl_domains << "$site.$developer.dev.mydomain.com"
  }
}

letsencrypt::certonly { 'dev-cert':
  domains     => $ssl_domains,
  plugin      => 'apache',
  manage_cron => true,
}

now it is impossible because of Puppet's variable scoping. How can I collect some variables in an array through nested loops?

Answer 1

You were close with your attempt, but you were using the wrong type of lambda. To avoid the issues resulting from the two facts that Puppet variables are immutable within the same scope and also cannot be used outside of a lambda scope if defined within a lambda, you must use an rvalue lambda https://en.wikipedia.org/wiki/Value_(computer_science)#R-values_and_addresses. I solved your problem using the rvalue lambda map https://docs.puppet.com/puppet/latest/function.html#map.

$site_developer_base = ['admin', 'api', 'web'].map |$site| {
  $developer_base = ['tom', 'jeff', 'harry'].map |$developer| {
    "${site}.${developer}.dev.mydomain.com"
  }
}

If I do a notify { $site_developer_base: } this outputs:

Notice: admin.tom.dev.mydomain.com
Notice: admin.jeff.dev.mydomain.com
Notice: admin.harry.dev.mydomain.com
Notice: api.tom.dev.mydomain.com
Notice: api.jeff.dev.mydomain.com
Notice: api.harry.dev.mydomain.com
Notice: web.tom.dev.mydomain.com
Notice: web.jeff.dev.mydomain.com
Notice: web.harry.dev.mydomain.com

proving that $site_developer_base has the array that you want.