+++ This bug was initially created as a clone of Bug #1717558 +++

Description of problem:

When deploying the undercloud, if you specify a non-normalized cidr in undercloud.conf for the control plane, such as 192.168.225.1/24, the deployment succeeds and the subnet is created correctly with 192.168.225.0/24.  If you attempt to perform a minor update to the undercloud, it fails because it looks for a network with the value in undercloud.conf (192.168.225.1/24), doesn't find it (because it's really 192.168.225.0/24) and then attempts to create the network for 192.168.225.1/24 which fails due to overlapping IP addresses.

Version-Release number of selected component (if applicable):

AFAIK, this issue exists in both OSP13 and OSP14.

How reproducible:


Steps to Reproduce:
1.
2.
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Actual results:


Expected results:


Additional info:

--- Additional comment from Harald Jensås on 2019-06-06 02:01:01 UTC ---

Neutron converts/normalizes the value provided as CIDR in a pre-commit method:
  https://opendev.org/openstack/neutron/src/branch/master/neutron/db/db_base_plugin_v2.py#L820

818            # turn the CIDR into a proper subnet
819            net = netaddr.IPNetwork(s['cidr'])
820            subnet['subnet']['cidr'] = '%s/%s' % (net.network, net.prefixlen)


This explain why we can create a subnet without the actual network address in the CIDR.


However when listing subnets and querying with a CIDR that does not use the actual network address, the result is empty:

$ curl -s -H "X-Auth-Token: $(openstack token issue -c id -f value)" -H "Content-Type: application/json" http://192.168.122.103:9696/v2.0/subnets?cidr=192.168.100.1/24 | json_reformat 
{
    "subnets": [

    ]
}


Looks like this patch would fix it neutron side:

--- a/neutron/db/db_base_plugin_common.py
+++ b/neutron/db/db_base_plugin_common.py
@@ -300,6 +300,12 @@ class DbBasePluginCommon(object):
                      page_reverse=False):
         pager = base_obj.Pager(sorts, limit, page_reverse, marker)
         filters = filters or {}
+        if filters.get('cidr'):
+            cidr_list = []
+            for cidr in filters['cidr']:
+                net = netaddr.IPNetwork(cidr)
+                cidr_list.append('%s/%s' % (net.network, net.prefixlen))
+            filters.update({'cidr': cidr_list})
         # TODO(ihrachys) remove explicit reader usage when subnet OVO switches
         # to engine facade by default
         with db_api.CONTEXT_READER.using(context):