(#13974) Add predicate functions for interface facts

If one wishes to test if a host has a particular IP address (such as a floating
virtual address) or has an interface on a particular network (such as a
secondary management network), the facts that provide this information are
difficult to use within Puppet.

This patch addresses these needs by implementing functions
‘has_ip_address(value)’ and ‘has_ip_network(value)’. These functions look
through all interfaces for ipaddress_<interface> and network_<interface>
(respectively) having the requested <value>.

These functions are implemented on top of a lower-level predicate
function, ‘has_interface_with(kind, value)’, which iterates through the
interfaces in the ‘interfaces’ fact and checks the facts <kind>_<interface>
looking for <value>.

Additionally, the existence of a particular named interface can be checked for
by calling with only a single argument: has_interface_with(interface).

A Boolean is returned in all cases.

1 files changed, 25 insertions, 0 deletions

diff --git a/lib/puppet/parser/functions/has_ip_network.rb b/lib/puppet/parser/functions/has_ip_network.rb
new file mode 100644
index 0000000..9ccf902
--- /dev/null
+++ b/lib/puppet/parser/functions/has_ip_network.rb
@@ -0,0 +1,25 @@
+#
+# has_ip_network
+#
+
+module Puppet::Parser::Functions
+  newfunction(:has_ip_network, :type => :rvalue, :doc => <<-EOS
+Returns true if the client has an IP address within the requested network.
+
+This function iterates through the 'interfaces' fact and checks the
+'network_IFACE' facts, performing a simple string comparision.
+    EOS
+  ) do |args|
+
+    raise(Puppet::ParseError, "has_ip_network(): Wrong number of arguments " +
+          "given (#{args.size} for 1)") if args.size != 1
+
+    Puppet::Parser::Functions.autoloader.load(:has_interface_with) \
+      unless Puppet::Parser::Functions.autoloader.loaded?(:has_interface_with)
+
+    function_has_interface_with(['network', args[0]])
+
+  end
+end
+
+# vim:sts=2 sw=2