How to sort an array of hashes by the value of a specific key of the hash?

[c33s]

i am trying to sort an array of hashes by a specific key of the hashes. in my case i have firewall rules which should be sorted by the order key of the hashes.

googling leads to the sort_by function which is only available in erb templates but not in epp or in puppet.

hiera.yaml:

rules:
    - {order: 1010, action: Invalid(DROP), source: net, dest: $FW, proto: tcp, comment: Drop packets in the INVALID state}
    - {order: 1020, action: Ping(DROP), source: net, dest: $FW, proto: tcp, comment: Drop Ping from the "bad" net zone.. and prevent your log from being flooded..}
    - {order: 1030, action: ACCEPT, source: $FW, dest: net, proto: icmp, comment: Permit all ICMP traffic FROM the firewall TO the net zone}

with erb it is no problem as i can use sort_by in the template:

rules.erb:

<% @rules.sort_by{|k,v| k['order']}.each do |rule| -%>
<%= rule['action'] %> <%= rule['source'] %> <%= rule['dest'] %>  <%= rule['proto'] %> #<%= rule['comment'] %>
<% end -%>

but because of the missing environment isolation of erb templates i would like to know how to do this with epp templates. also i would be interested how to do that in puppet (a class or a define) itself (simply because it's good to know how to do that).

[b4ldr]

you can use the following in puppet >= 6 or with puppetlabs-stdlib

[{'order' => 1}, {'order' => 3}, {'order' => 2}].sort |$a, $b| { compare($a['order'], $b['order'])  }