ifconfig: T2653: add common vyos.configverify helpers

While moving towards a general interface abstraction based on get_config_dict()
and the use of vyos.ifconfig.Interfaces().update() it also makes sense, to
split out common verification code to a common util file - instead of
duplicating the code, which is infact one of the main forces drivind this
transition.

vyos.configverify will hold common functions called via verify() from our
src/conf_mode scripts so we do not need to copy/paste general verifications
methods.

1 files changed, 67 insertions, 0 deletions

diff --git a/python/vyos/configverify.py b/python/vyos/configverify.py
new file mode 100644
index 000000000..64eb80728
--- /dev/null
+++ b/python/vyos/configverify.py
@@ -0,0 +1,67 @@
+# Copyright 2020 VyOS maintainers and contributors <maintainers@vyos.io>
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library.  If not, see <http://www.gnu.org/licenses/>.
+
+# The sole purpose of this module is to hold common functions used in
+# all kinds of implementations to verify the CLI configuration.
+# It is started by migrating the interfaces to the new get_config_dict()
+# approach which will lead to a lot of code that can be reused.
+
+# NOTE: imports should be as local as possible to the function which
+# makes use of it!
+
+def verify_bridge_vrf(config):
+    """
+    Common helper function used by interface implementations to
+    perform recurring validation of VRF configuration
+    """
+    from netifaces import interfaces
+    from vyos import ConfigError
+
+    if 'vrf' in config.keys():
+        if config['vrf'] not in interfaces():
+            raise ConfigError('VRF "{vrf}" does not exist'.format(**config))
+
+        if 'is_bridge_member' in config.keys():
+            raise ConfigError(
+                'Interface "{ifname}" cannot be both a member of VRF "{vrf}" '
+                'and bridge "{is_bridge_member}"!'.format(**config))
+
+
+def verify_bridge_address(config):
+    """
+    Common helper function used by interface implementations to
+    perform recurring validation of IP address assignmenr
+    when interface also is part of a bridge.
+    """
+    from vyos import ConfigError
+
+    if {'is_bridge_member', 'address'} <= set(config):
+        raise ConfigError(
+            f'Cannot assign address to interface "{ifname}" as it is a '
+            f'member of bridge "{is_bridge_member}"!'.format(**config))
+
+
+def verify_bridge_delete(config):
+    """
+    Common helper function used by interface implementations to
+    perform recurring validation of IP address assignmenr
+    when interface also is part of a bridge.
+    """
+    from vyos import ConfigError
+
+    if 'is_bridge_member' in config.keys():
+        raise ConfigError(
+            'Interface "{ifname}" cannot be deleted as it is a '
+            'member of bridge "{is_bridge_member}"!'.format(**config))