[train-only] Validate rendered net_config_override

In change I127c2742522e695dd1fd15413a47bf4d8ebea8fa the
_validate_no_ip_change validation was updated to check for
ip address change in net_config_override template - when a
template using mapping keys like {{PUBLIC_INTERFACE_IP}} the
validation will fail since netaddr cannot parse that as an IP
address.

As was done for OSP17, pass in the rendered network_config_json
to the preflight check and validate against this when checking
for a changed IP address.

Also whe net_config_override allow a match with
CONF.undercloud_public_host to pass validation since doc's and
example net_config_override uses {{PUBLIC_INTERFACE_IP}} not
{{LOCAL_IP}}.

Change-Id: Ia01cfc6957536939232085dd6973ab0b105fe78a

tripleoclient/v1/undercloud_config.py

@@ -753,6 +753,7 @@ def prepare_undercloud_deploy(upgrade=False, no_validations=True,
     if CONF.get('cleanup'):
         deploy_args.append('--cleanup')
 
+    net_config_json = None
     if CONF.get('net_config_override', None):
         data_file = CONF['net_config_override']
         if os.path.abspath(data_file) != data_file:
@@ -825,7 +826,8 @@ def prepare_undercloud_deploy(upgrade=False, no_validations=True,
 
     if CONF.get('enable_validations') and not no_validations:
         utils.ansible_symlink()
-        undercloud_preflight.check(verbose_level, upgrade)
+        undercloud_preflight.check(verbose_level, upgrade,
+                                   net_config_json=net_config_json)
         deploy_args += ['-e', os.path.join(
             tht_templates, "environments/tripleo-validations.yaml")]
 

tripleoclient/v1/undercloud_preflight.py

@@ -287,7 +287,7 @@ def _validate_interface_exists(config_var='local_interface'):
         raise FailedValidation(message)
 
 
-def _validate_no_ip_change():
+def _validate_no_ip_change(net_config_json=None):
     """Disallow provisioning interface IP changes
 
     Changing the provisioning network IP causes a number of issues, so we
@@ -295,34 +295,53 @@ def _validate_no_ip_change():
     be changed.
     """
     if CONF.net_config_override:
-        os_net_config_file = CONF.net_config_override
+        network_config = net_config_json
     else:
-        os_net_config_file = '/etc/os-net-config/config.json'
-    # Nothing to do if we haven't already installed
-    if not os.path.isfile(
-            os.path.expanduser(os_net_config_file)):
-        return
-    try:
+        os_net_config_file = '/etc/os-net-config/config.yaml'
+
+        if not os.path.isfile(os.path.expanduser(os_net_config_file)):
+            os_net_config_file = '/etc/os-net-config/config.json'
+
+        # Nothing to do if we haven't already installed
+        if not os.path.isfile(os.path.expanduser(os_net_config_file)):
+            return
+
         with open(os_net_config_file, 'r') as f:
             network_config = yaml.safe_load(f)
-        ctlplane = [i for i in network_config.get('network_config', [])
-                    if i['name'] == 'br-ctlplane'][0]
-    except ValueError:
+
+    if network_config is None:
         # File was empty
         return
+
+    try:
+        ctlplane = [i for i in network_config.get('network_config', [])
+                    if i.get('name') == 'br-ctlplane'][0]
     except IndexError:
         # Nothing to check if br-ctlplane wasn't configured
         return
+
     existing_ip = ctlplane['addresses'][0]['ip_netmask']
     conf_netaddr = netaddr.IPNetwork(CONF.local_ip)
+    conf_public_netaddr = netaddr.IPNetwork(CONF.undercloud_public_host)
     existing_netaddr = netaddr.IPNetwork(existing_ip)
-    if (conf_netaddr != existing_netaddr
-            or conf_netaddr.ip != existing_netaddr.ip):
-        message = _('Changing the local_ip is not allowed.  Existing IP: '
-                    '{0}, Configured IP: {1}').format(
-                        existing_ip, CONF.local_ip)
-        LOG.error(message)
-        raise FailedValidation(message)
+    # NOTE(hjensas):
+    #   {{PUBLIC_INTERFACE_IP}} maps to CONF.undercloud_public_host
+    #   {{LOCAL_IP}} maps to CONF.local_ip
+    # In several examples and docs {{PUBLIC_INTERFACE_IP}} is
+    # used in net_config_override templates instead of {{LOCAL_IP}}
+    # so let's make that OK.
+    if (CONF.net_config_override
+            and (conf_public_netaddr == existing_netaddr
+                 and conf_public_netaddr.ip == existing_netaddr.ip)):
+        return
+    if (conf_netaddr == existing_netaddr
+            and conf_netaddr.ip == existing_netaddr.ip):
+        return
+
+    message = _('Changing the local_ip is not allowed.  Existing IP: '
+                '{0}, Configured IP: {1}').format(existing_ip, CONF.local_ip)
+    LOG.error(message)
+    raise FailedValidation(message)
 
 
 def _validate_passwords_file():
@@ -475,7 +494,7 @@ def _check_all_or_no_subnets_use_dns_nameservers():
         raise FailedValidation(message)
 
 
-def check(verbose_level, upgrade=False):
+def check(verbose_level, upgrade=False, net_config_json=None):
     # Fetch configuration and use its log file param to add logging to a file
     utils.load_config(CONF, constants.UNDERCLOUD_CONF_PATH)
     utils.configure_logging(LOG, verbose_level, CONF['undercloud_log_file'])
@@ -518,7 +537,7 @@ def check(verbose_level, upgrade=False):
         _checking_status('Network interfaces')
         _validate_interface_exists()
         _checking_status('Provisionning IP change')
-        _validate_no_ip_change()
+        _validate_no_ip_change(net_config_json=net_config_json)
         _checking_status('Architecture')
         _validate_architecure_options()
     except KeyError as e: