From 30ed29ed46c5c3c9cee3769516e335dd61fd2edf Mon Sep 17 00:00:00 2001
From: Charl van Niekerk <charl.vanniekerk@eu.equinix.com>
Date: Tue, 23 Jan 2018 15:14:56 +0100
Subject: [PATCH] Implement the reduce_on_network method to filter a list of IP
 addresses on a given range. (#34929) (#34930)

---
 lib/ansible/plugins/filter/ipaddr.py | 34 ++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)

diff --git a/lib/ansible/plugins/filter/ipaddr.py b/lib/ansible/plugins/filter/ipaddr.py
index e27e7c4e3b..a9c1649572 100644
--- a/lib/ansible/plugins/filter/ipaddr.py
+++ b/lib/ansible/plugins/filter/ipaddr.py
@@ -900,6 +900,39 @@ def network_in_network(value, test):
         return False
 
 
+def reduce_on_network(value, network):
+    '''
+    Reduces a list of addresses to only the addresses that match a given network.
+
+    :param: value: The list of addresses to filter on.
+    :param: network: The network to validate against.
+
+    :return: The reduced list of addresses.
+    '''
+    # normalize network variable into an ipaddr
+    n = _address_normalizer(network)
+
+    # get first and last addresses as integers to compare value and test; or cathes value when case is /32
+    n_first = ipaddr(ipaddr(n, 'network') or ipaddr(n, 'address'), 'int')
+    n_last = ipaddr(ipaddr(n, 'broadcast') or ipaddr(n, 'address'), 'int')
+
+    # create an empty list to fill and return
+    r = []
+
+    for address in value:
+        # normalize address variables into an ipaddr
+        a = _address_normalizer(address)
+
+        # get first and last addresses as integers to compare value and test; or cathes value when case is /32
+        a_first = ipaddr(ipaddr(a, 'network') or ipaddr(a, 'address'), 'int')
+        a_last = ipaddr(ipaddr(a, 'broadcast') or ipaddr(a, 'address'), 'int')
+
+        if _range_checker(a_first, n_first, n_last) and _range_checker(a_last, n_first, n_last):
+            r.append(address)
+
+    return r
+
+
 # Returns the SLAAC address within a network for a given HW/MAC address.
 # Usage:
 #
@@ -1002,6 +1035,7 @@ class FilterModule(object):
         'next_nth_usable': next_nth_usable,
         'network_in_network': network_in_network,
         'network_in_usable': network_in_usable,
+        'reduce_on_network': reduce_on_network,
         'nthhost': nthhost,
         'previous_nth_usable': previous_nth_usable,
         'slaac': slaac,