vrf: T6189: render FRR L3VNI configuration when creating VRF instance

When adding and removing VRF instances on the fly it was noticed that the vni
statement under the VRF instance in FRR vanishes. This was caused by a race
condition which was previously designed to fix another bug.

The wierd design of a Python helper below the VRF tree to only generate the
VNI configuration nodes is now gone and all is rendered in the proper place.

(cherry picked from commit e7bb65894f86372dc0f6e8fd39b1628e0a224c68)

1 files changed, 43 insertions, 12 deletions

diff --git a/smoketest/scripts/cli/test_vrf.py b/smoketest/scripts/cli/test_vrf.py
index f6e4181c0..243397dc2 100755
--- a/smoketest/scripts/cli/test_vrf.py
+++ b/smoketest/scripts/cli/test_vrf.py
@@ -18,7 +18,6 @@ import re
 import os
 import unittest
 
-from netifaces import interfaces
 from base_vyostest_shim import VyOSUnitTestSHIM
 
 from vyos.configsession import ConfigSessionError
@@ -27,6 +26,7 @@ from vyos.ifconfig import Section
 from vyos.utils.file import read_file
 from vyos.utils.network import get_interface_config
 from vyos.utils.network import is_intf_addr_assigned
+from vyos.utils.network import interface_exists
 from vyos.utils.system import sysctl_read
 
 base_path = ['vrf']
@@ -60,7 +60,7 @@ class VRFTest(VyOSUnitTestSHIM.TestCase):
         self.cli_delete(base_path)
         self.cli_commit()
         for vrf in vrfs:
-            self.assertNotIn(vrf, interfaces())
+            self.assertFalse(interface_exists(vrf))
 
     def test_vrf_vni_and_table_id(self):
         base_table = '1000'
@@ -89,7 +89,7 @@ class VRFTest(VyOSUnitTestSHIM.TestCase):
         iproute2_config = read_file('/etc/iproute2/rt_tables.d/vyos-vrf.conf')
         for vrf in vrfs:
             description = f'VyOS-VRF-{vrf}'
-            self.assertTrue(vrf in interfaces())
+            self.assertTrue(interface_exists(vrf))
             vrf_if = Interface(vrf)
             # validate proper interface description
             self.assertEqual(vrf_if.get_alias(), description)
@@ -131,7 +131,7 @@ class VRFTest(VyOSUnitTestSHIM.TestCase):
         loopbacks = ['127.0.0.1', '::1']
         for vrf in vrfs:
             # Ensure VRF was created
-            self.assertIn(vrf, interfaces())
+            self.assertTrue(interface_exists(vrf))
             # Verify IP forwarding is 1 (enabled)
             self.assertEqual(sysctl_read(f'net.ipv4.conf.{vrf}.forwarding'), '1')
             self.assertEqual(sysctl_read(f'net.ipv6.conf.{vrf}.forwarding'), '1')
@@ -171,7 +171,7 @@ class VRFTest(VyOSUnitTestSHIM.TestCase):
         self.cli_commit()
 
         # Check if VRF has been created
-        self.assertTrue(vrf in interfaces())
+        self.assertTrue(interface_exists(vrf))
 
         table = str(int(table) + 1)
         self.cli_set(base + ['table', table])
@@ -228,7 +228,7 @@ class VRFTest(VyOSUnitTestSHIM.TestCase):
             next_hop = f'192.0.{table}.1'
             prefix = f'10.0.{table}.0/24'
 
-            self.assertTrue(vrf in interfaces())
+            self.assertTrue(interface_exists(vrf))
 
             frrconfig = self.getFRRconfig(f'vrf {vrf}')
             self.assertIn(f' vni {table}', frrconfig)
@@ -261,7 +261,7 @@ class VRFTest(VyOSUnitTestSHIM.TestCase):
         # Apply VRF config
         self.cli_commit()
         # Ensure VRF got created
-        self.assertIn(vrf, interfaces())
+        self.assertTrue(interface_exists(vrf))
         # ... and IP addresses are still assigned
         for address in addresses:
             self.assertTrue(is_intf_addr_assigned(interface, address))
@@ -293,7 +293,7 @@ class VRFTest(VyOSUnitTestSHIM.TestCase):
         loopbacks = ['127.0.0.1', '::1']
         for vrf in vrfs:
             # Ensure VRF was created
-            self.assertIn(vrf, interfaces())
+            self.assertTrue(interface_exists(vrf))
             # Verify IP forwarding is 0 (disabled)
             self.assertEqual(sysctl_read(f'net.ipv4.conf.{vrf}.forwarding'), '0')
             self.assertEqual(sysctl_read(f'net.ipv6.conf.{vrf}.forwarding'), '0')
@@ -425,7 +425,7 @@ class VRFTest(VyOSUnitTestSHIM.TestCase):
         # Verify VRF configuration
         table = base_table
         for vrf in vrfs:
-            self.assertTrue(vrf in interfaces())
+            self.assertTrue(interface_exists(vrf))
 
             frrconfig = self.getFRRconfig(f'vrf {vrf}')
             self.assertIn(f' vni {table}', frrconfig)
@@ -447,7 +447,7 @@ class VRFTest(VyOSUnitTestSHIM.TestCase):
         # Verify VRF configuration
         table = base_table
         for vrf in vrfs:
-            self.assertTrue(vrf in interfaces())
+            self.assertTrue(interface_exists(vrf))
 
             frrconfig = self.getFRRconfig(f'vrf {vrf}')
             self.assertIn(f' vni {table}', frrconfig)
@@ -470,13 +470,39 @@ class VRFTest(VyOSUnitTestSHIM.TestCase):
         # Verify VRF configuration
         table = base_table
         for vrf in vrfs:
-            self.assertTrue(vrf in interfaces())
+            self.assertTrue(interface_exists(vrf))
 
             frrconfig = self.getFRRconfig(f'vrf {vrf}')
             self.assertIn(f' vni {table}', frrconfig)
             # Increment table ID for the next run
             table = str(int(table) + 2)
 
+
+        # add a new VRF with VNI - this must not delete any existing VRF/VNI
+        purple = 'purple'
+        table = str(int(table) + 10)
+        self.cli_set(base_path + ['name', purple, 'table', table])
+        self.cli_set(base_path + ['name', purple, 'vni', table])
+
+        # commit changes
+        self.cli_commit()
+
+        # Verify VRF configuration
+        table = base_table
+        for vrf in vrfs:
+            self.assertTrue(interface_exists(vrf))
+
+            frrconfig = self.getFRRconfig(f'vrf {vrf}')
+            self.assertIn(f' vni {table}', frrconfig)
+            # Increment table ID for the next run
+            table = str(int(table) + 2)
+
+        # Verify purple VRF/VNI
+        self.assertTrue(interface_exists(purple))
+        table = str(int(table) + 10)
+        frrconfig = self.getFRRconfig(f'vrf {purple}')
+        self.assertIn(f' vni {table}', frrconfig)
+
         # Now delete all the VNIs
         for vrf in vrfs:
             base = base_path + ['name', vrf]
@@ -487,11 +513,16 @@ class VRFTest(VyOSUnitTestSHIM.TestCase):
 
         # Verify no VNI is defined
         for vrf in vrfs:
-            self.assertTrue(vrf in interfaces())
+            self.assertTrue(interface_exists(vrf))
 
             frrconfig = self.getFRRconfig(f'vrf {vrf}')
             self.assertNotIn('vni', frrconfig)
 
+        # Verify purple VNI remains
+        self.assertTrue(interface_exists(purple))
+        frrconfig = self.getFRRconfig(f'vrf {purple}')
+        self.assertIn(f' vni {table}', frrconfig)
+
     def test_vrf_ip_ipv6_nht(self):
         table = '6910'