NSX|V: add in exclusive DHCP support

Via the configuration variable exclusive_dhcp_edge enable a tenant
to create a exclusive DHCP edge. This can be global or via AZ.

DocImpact

Change-Id: Ia5220302114d73fa89b3f3ea86141cb3208fe885

releasenotes/notes/nsxv-exclusive-dhcp-7e5cde1cd88f8c5b.yaml

@@ -0,0 +1,8 @@
+---
+prelude: >
+    Add support for exclusive DHCP edges.
+features:
+  - |
+    The NSX-v will now enable a tenant to deploy a exclusive DHCP edge. This
+    is either via the global configuration variable ``exclusive_dhcp_edge`` or
+    per AZ. By default this is disabled.

vmware_nsx/common/config.py

@@ -663,6 +663,9 @@ nsxv_opts = [
                        "connectivity between hosts on same network via "
                        "their floating ips. If True, floating ip will "
                        "be associated with all router interfaces.")),
+    cfg.BoolOpt('exclusive_dhcp_edge',
+                default=False,
+                help=_("(Optional) Have exclusive DHCP edge per network.")),
 ]
 
 # define the configuration of each availability zone.
@@ -718,6 +721,9 @@ nsxv_az_opts = [
     cfg.StrOpt('dvs_id',
                help=_('(Optional) DVS MoRef ID for DVS connected to '
                       'Management / Edge cluster')),
+    cfg.BoolOpt('exclusive_dhcp_edge',
+                default=False,
+                help=_("(Optional) Have exclusive DHCP edge per network.")),
 ]
 
 # Register the configuration options

vmware_nsx/plugins/nsx_v/availability_zones.py

@@ -65,6 +65,7 @@ class NsxVAvailabilityZone(common_az.ConfiguredAvailabilityZone):
         self.vdn_scope_id = cfg.CONF.nsxv.vdn_scope_id
         self.dvs_id = cfg.CONF.nsxv.dvs_id
         self.edge_host_groups = cfg.CONF.nsxv.edge_host_groups
+        self.exclusive_dhcp_edge = cfg.CONF.nsxv.exclusive_dhcp_edge
 
         # No support for metadata per az
         self.az_metadata_support = False
@@ -121,6 +122,8 @@ class NsxVAvailabilityZone(common_az.ConfiguredAvailabilityZone):
         if not self.edge_host_groups:
             self.edge_host_groups = cfg.CONF.nsxv.edge_host_groups
 
+        self.exclusive_dhcp_edge = az_info.get('exclusive_dhcp_edge', False)
+
         # Support for metadata per az only if configured, and different
         # from the global one
         self.mgt_net_proxy_ips = az_info.get('mgt_net_proxy_ips')
@@ -178,6 +181,7 @@ class NsxVAvailabilityZone(common_az.ConfiguredAvailabilityZone):
         self.vdn_scope_id = cfg.CONF.nsxv.vdn_scope_id
         self.dvs_id = cfg.CONF.nsxv.dvs_id
         self.edge_host_groups = cfg.CONF.nsxv.edge_host_groups
+        self.exclusive_dhcp_edge = cfg.CONF.nsxv.exclusive_dhcp_edge
 
     def supports_metadata(self):
         # Return True if this az has it's own metadata configuration

vmware_nsx/plugins/nsx_v/vshield/edge_utils.py

@@ -1123,8 +1123,10 @@ class EdgeManager(object):
                 free_number = ((vcns_const.MAX_VNIC_NUM - 1) *
                                vcns_const.MAX_TUNNEL_NUM -
                                len(edge_vnic_bindings))
-                # metadata internal network will use one vnic
-                if free_number <= (vcns_const.MAX_TUNNEL_NUM - 1):
+                # metadata internal network will use one vnic or
+                # exclusive_dhcp_edge is set for the AZ
+                if (free_number <= (vcns_const.MAX_TUNNEL_NUM - 1) or
+                    availability_zone.exclusive_dhcp_edge):
                     conflict_edge_ids.append(dhcp_edge_id)
 
             for net_id in conflicting_nets: