V2T validation: verify external subnets before migration

Check that the future external networks will not overlap with the tier0 uplinks

Change-Id: I4678f345a8b2e6d10d027d4b109e4604a37f685a

doc/source/admin_util.rst

@@ -680,6 +680,16 @@ NSX Policy Plugin
 
     nsxadmin -r nsx-migrate-t2p -o clean-all
 
+- Cleanup redundant migrated objects post V2T migration::
+
+    nsxadmin -r nsx-migrate-v2t -o clean-all
+
+- Disable/Restore Tier0 redistribution of tier1 routes during the V2T migration::
+    nsxadmin -r nsx-migrate-v2t -o nsx-redistribute --property action=disable/restore --property tier0s=a,b,c
+
+- Validate external subnets cidrs before V2T migration::
+
+    nsxadmin -r nsx-migrate-v2t -o validate --property ext-net=<path> --property ext-cidr=<path>
 
 Client Certificate
 ~~~~~~~~~~~~~~~~~~
@@ -704,12 +714,6 @@ Client Certificate
 
     nsxadmin -r certificate -o nsx-list
 
-- Cleanup redundant migrated objects post V2T migration::
-
-    nsxadmin -r nsx-migrate-v2t -o clean-all
-
-- Disable/Restore Tier0 redistribution of tier1 routes during the migration::
-    nsxadmin -r nsx-migrate-v2t -o nsx-redistribute --property action=disable/restore --property tier0s=a,b,c
 
 Steps to create a TVD admin user
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

vmware_nsx/shell/admin/plugins/nsxp/resources/migration.py

@@ -13,6 +13,9 @@
 #    under the License.
 
 import copy
+import sys
+
+import netaddr
 
 from neutron_lib.callbacks import registry
 from oslo_log import log as logging
@@ -154,6 +157,56 @@ def migration_tier0_redistribute(resource, event, trigger, **kwargs):
         LOG.error("%s", errmsg)
 
 
+def _cidrs_overlap(cidr0, cidr1):
+    return cidr0.first <= cidr1.last and cidr1.first <= cidr0.last
+
+
+@admin_utils.output_header
+def migration_validate_external_cidrs(resource, event, trigger, **kwargs):
+    """Before V2T migration, validate that the external subnets cidrs
+    do not overlap the tier0 uplinks
+    """
+    errmsg = ("Need to specify --property ext-net=<path> --property "
+              "ext-cidr=<path>")
+    if not kwargs.get('property'):
+        LOG.error("%s", errmsg)
+        return
+
+    properties = admin_utils.parse_multi_keyval_opt(kwargs['property'])
+    ext_net_file = properties.get('ext-net')
+    ext_cidr_file = properties.get('ext-cidr')
+    if not ext_net_file or not ext_cidr_file:
+        LOG.error("%s", errmsg)
+        return
+
+    with open(ext_net_file, 'r') as myfile:
+        # maps external network neutron id to tier0
+        data = myfile.read()
+        external_networks = jsonutils.loads(data)
+    with open(ext_cidr_file, 'r') as myfile:
+        # maps external network neutron id to its cidr
+        data = myfile.read()
+        external_cidrs = jsonutils.loads(data)
+
+    nsxpolicy = p_utils.get_connected_nsxpolicy()
+
+    for net_id in external_cidrs:
+        net_cidr = netaddr.IPNetwork(external_cidrs[net_id]).cidr
+        tier0 = external_networks.get(net_id)
+        if not tier0:
+            LOG.warning("Could not find network %s in %s",
+                        net_id, ext_net_file)
+        else:
+            tier0_cidrs = nsxpolicy.tier0.get_uplink_cidrs(tier0)
+            for cidr in tier0_cidrs:
+                tier0_subnet = netaddr.IPNetwork(cidr).cidr
+                if _cidrs_overlap(tier0_subnet, net_cidr):
+                    LOG.error("External subnet of network %s cannot overlap "
+                              "with T0 %s uplink cidr %s", net_id, tier0, cidr)
+                    sys.exit(1)
+    sys.exit(0)
+
+
 registry.subscribe(cleanup_db_mappings,
                    constants.NSX_MIGRATE_T_P,
                    shell.Operations.CLEAN_ALL.value)
@@ -165,3 +218,7 @@ registry.subscribe(post_v2t_migration_cleanups,
 registry.subscribe(migration_tier0_redistribute,
                    constants.NSX_MIGRATE_V_T,
                    shell.Operations.NSX_REDISTRIBUTE.value)
+
+registry.subscribe(migration_validate_external_cidrs,
+                   constants.NSX_MIGRATE_V_T,
+                   shell.Operations.VALIDATE.value)

vmware_nsx/shell/resources.py

@@ -292,6 +292,7 @@ nsxp_resources = {
                                         [Operations.CLEAN_ALL.value]),
     constants.NSX_MIGRATE_V_T: Resource(constants.NSX_MIGRATE_V_T,
                                         [Operations.CLEAN_ALL.value,
+                                         Operations.VALIDATE.value,
                                          Operations.NSX_REDISTRIBUTE.value]),
 }