Useful usage of #Puppet's "plusignment" operator (+>):
Apache::Vhost <| port == 443 |> {
headers +> [
'always set Strict-Transport-Security "max-age=63072000; includeSubDomains; preload"',
],
}
Lots of duplication removed!
https://puppet.com/docs/puppet/5.5/lang_classes.html#appending-to-resource-attributes