vrf: T3734: T3728: vni must be configured with a higher priority then bgpd

When removing bgp (vrf) instances the assigned VRF vni must be deleted from FRR
prior the removal of the bgp settings (T3734).

This is now done by moving the CLI command "set vrf name red vni 1000" to a
dedicated Python script with a priority higher then bgp.

2 files changed, 76 insertions, 20 deletions

diff --git a/src/conf_mode/vrf.py b/src/conf_mode/vrf.py
index c1cfc1dcb..919083ac4 100755
--- a/src/conf_mode/vrf.py
+++ b/src/conf_mode/vrf.py
@@ -24,7 +24,6 @@ from vyos.config import Config
 from vyos.configdict import node_changed
 from vyos.ifconfig import Interface
 from vyos.template import render
-from vyos.template import render_to_string
 from vyos.util import call
 from vyos.util import cmd
 from vyos.util import dict_search
@@ -32,12 +31,9 @@ from vyos.util import get_interface_config
 from vyos.util import popen
 from vyos.util import run
 from vyos import ConfigError
-from vyos import frr
 from vyos import airbag
 airbag.enable()
 
-frr_daemon = 'zebra'
-
 config_file = r'/etc/iproute2/rt_tables.d/vyos-vrf.conf'
 
 def list_rules():
@@ -131,7 +127,6 @@ def verify(vrf):
 
 def generate(vrf):
     render(config_file, 'vrf/vrf.conf.tmpl', vrf)
-    vrf['new_frr_config'] = render_to_string('frr/vrf.frr.tmpl', vrf)
     # Render nftables zones config
     vrf['nft_vrf_zones'] = NamedTemporaryFile().name
     render(vrf['nft_vrf_zones'], 'firewall/nftables-vrf-zones.tmpl', vrf)
@@ -242,21 +237,6 @@ def apply(vrf):
         if tmp == 0:
             cmd('nft delete table inet vrf_zones')
 
-    #   T3694: Somehow we hit a priority inversion here as we need to remove the
-    #   VRF assigned VNI before we can remove a BGP bound VRF instance. Maybe
-    #   move this to an individual helper script that set's up the VNI for the
-    #   given VRF after any routing protocol.
-    #
-    #   # add configuration to FRR
-    #   frr_cfg = frr.FRRConfig()
-    #   frr_cfg.load_configuration(frr_daemon)
-    #   frr_cfg.modify_section(f'^vrf [a-zA-Z-]*$', '')
-    #   frr_cfg.add_before(r'(interface .*|line vty)', vrf['new_frr_config'])
-    #   frr_cfg.commit_configuration(frr_daemon)
-    #
-    #   # Save configuration to /run/frr/config/frr.conf
-    #   frr.save_configuration()
-
     return None
 
 if __name__ == '__main__':
diff --git a/src/conf_mode/vrf_vni.py b/src/conf_mode/vrf_vni.py
new file mode 100755
index 000000000..87ee8f2d1
--- /dev/null
+++ b/src/conf_mode/vrf_vni.py
@@ -0,0 +1,76 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2020-2021 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+from sys import argv
+from sys import exit
+
+from vyos.config import Config
+from vyos.template import render_to_string
+from vyos import ConfigError
+from vyos import frr
+from vyos import airbag
+airbag.enable()
+
+frr_daemon = 'zebra'
+
+def get_config(config=None):
+    if config:
+        conf = config
+    else:
+        conf = Config()
+
+    # This script only works with a passed VRF name
+    if len(argv) < 1:
+        raise NotImplementedError
+    vrf = argv[1]
+
+    # "assemble" dict - easier here then use a full blown get_config_dict()
+    # on a single leafNode
+    vni = { 'vrf' : vrf }
+    tmp = conf.return_value(['vrf', 'name', vrf, 'vni'])
+    if tmp: vni.update({ 'vni' : tmp })
+
+    return vni
+
+def verify(vni):
+    return None
+
+def generate(vni):
+    vni['new_frr_config'] = render_to_string('frr/vrf-vni.frr.tmpl', vni)
+    return None
+
+def apply(vni):
+    # add configuration to FRR
+    frr_cfg = frr.FRRConfig()
+    frr_cfg.load_configuration(frr_daemon)
+    frr_cfg.modify_section(f'^vrf [a-zA-Z-]*$', '')
+    frr_cfg.add_before(r'(interface .*|line vty)', vni['new_frr_config'])
+    frr_cfg.commit_configuration(frr_daemon)
+
+    # Save configuration to /run/frr/config/frr.conf
+    frr.save_configuration()
+
+    return None
+
+if __name__ == '__main__':
+    try:
+        c = get_config()
+        verify(c)
+        generate(c)
+        apply(c)
+    except ConfigError as e:
+        print(e)
+        exit(1)