Given an array of hostnames, how can I generate a set of files based on those hostnames in puppet - puppet

Question

I am not sure there is a way to even do this in puppet, but here is what I am trying to do.
Given this skeletal puppet class definition ...
class make_files (
$rabbit_servers = ['rabbit-1','rabbit-2'],
$mongo_servers = ['mongo-1','mongo-2'],
) {
...
}
... generate the files ...
# pwd
/root/conf/hosts
# more rabbit-*
::::::::::::::
rabbit-1.cfg
::::::::::::::
define host {
use linux-server
host_name rabbit-1
alias Rabbit MQ host
hostgroups rabbit_hosts
address 10.29.103.33
}
::::::::::::::
rabbit-2.cfg
::::::::::::::
define host {
use linux-server
host_name rabbit-2
alias Rabbit MQ host
hostgroups rabbit_hosts
address 10.29.103.34
}
# more mongo-*
::::::::::::::
mongo-1.cfg
::::::::::::::
define host {
use linux-server
host_name mongo-1
alias Mongo DB host
hostgroups mongo_hosts
address 10.29.103.31
}
::::::::::::::
mongo-2.cfg
::::::::::::::
define host {
use linux-server
host_name mongo-2
alias Mongo DB host
hostgroups mongo_hosts
address 10.29.103.32
}
Where the IP addresses are the IP address of the corresponding host.
Any help is much appreciated.

Answer 1

If the names belong to nodes that are managed by Puppet, you can fetch the addresses from PuppetDB directly using the puppetdbquery module
$ipaddress = query_facts("hostname=$host_name", ['ipaddress'])['ipaddress']
The code is untested, I'm not sure whether the invocation is correct.

Answer 2

I have found a solution ...
class make_files (
$rabbit_servers = ['rabbit-1:10.29.103.33','rabbit-2:10.29.103.34'],
$mongo_servers = ['ost-mongo-el7-001:10.29.103.31'],
) {
define my_file ($content, $hostgroup) {
$tuple = split($name, ':')
$host_name = $tuple[0]
$file_name = "/tmp/$host_name.cfg"
$ipaddress = $tuple[1]
$config = "define host {
use linux-server
host_name $host_name
alias $host_name
hostgroups $hostgroup
address $ipaddress
}"
file { $file_name:
ensure => file,
content => $config,
}
}
$rabbit_content = join($rabbit_servers, ',')
my_file { $rabbit_servers: content => $rabbit_content, hostgroup => 'rabbit_hosts' }
$mongo_content = join($mongo_servers, ',')
my_file { $mongo_servers: content => $mongo_content, hostgroup => 'mongo_hosts' }
}
... and I found that I needed to change the content of the files slightly.
This is probably not the best answer but it seems to work. I am open to suggested improvements.
Thanks