netstdlib
is a collection of puppet functions and facts for network related work.
These functions and facts are very handy when using puppet to do complex logic on code that deals with configuring or interpreting network interfaces.
Most of them simply expose the native ruby implementations into the puppet manifest so you can use them to say, edit OpenStack config files, or manipulate DCHP server pools.
Examples
# Use macaddress_rand instead of FQDNs because we have lots of VMs with
# the same hostname
cron::d { 'puppet_agent':
ensure => $ensure,
minute => macaddress_rand(60),
user => 'root',
command => 'puppet agent -t >/dev/null 2>&1',
}
# Have the puppet server query DNS to get the current round-robin A records
$web_server_ips_array = gethostbyname2array("webs.yourdomain.com")
validate_array($web_server_ips_array)
# Reverse Lookup your ip to a name:
$my_name = gethostbyaddr2array($::ipaddress)
notify { "My reverse dns seems to be: ${my_name}": }
##Functions
cidr_to_broadcast
Converts an CIDR address of the form 192.168.0.1/24 into its broadcast address
cidr_to_netmask
Converts an CIDR address of the form 192.168.0.1/24 into its netmask address
cidr_to_network
Converts an CIDR address of the form 192.168.0.1/24 into its network address
fqdn_mac
Generate MAC addresses based on the results of fqdn_rand. Useful for VMs that might have the same hostname.
gethostbyaddr2array
Resolve an IP address into one or more names. (Looks up reverse DNS PTRs)
gethostbyname2array
Resolve a name into one or more IP addresses.
int_to_ip
Converts an IP in its 32 bit integer representation to a dotted address of the form 192.168.0.1
ip_in_cidr
Checks if an ip address is contained within a CIDR address of the form 192.168.0.1/24
ip_to_int
Converts a dotted address of the form 192.168.0.1 into its 32 bit integer representation
mac_to_eui64
Converts a MAC address of the form 52:54:00:12:09:f3 into its EUI64 representation of the form 5054:00ff:fe12:09f3
netmask_to_masklen
Converts a netmask of the form 255.255.0.0 to the mask length (e.g. 16)
##Limitations
Puppet functions are server-side, facts are client side. Keep this in mind as any DNS related functions will take place on the server.