[config] Prevent deleting VLAN with IP addresses. (sonic-net#1429)

Warn user while deleting VLAN if it has IP addresses.
Signed-off-by: d-dashkov <[email protected]>

Author: d-dashkov

config/vlan.py

@@ -46,6 +46,12 @@ def del_vlan(db, vid):
     if clicommon.check_if_vlanid_exist(db.cfgdb, vlan) == False:
         ctx.fail("{} does not exist".format(vlan))
 
+    intf_table = db.cfgdb.get_table('VLAN_INTERFACE')
+    for intf_key in intf_table:
+        if ((type(intf_key) is str and intf_key == 'Vlan{}'.format(vid)) or
+            (type(intf_key) is tuple and intf_key[0] == 'Vlan{}'.format(vid))):
+            ctx.fail("{} can not be removed. First remove IP addresses assigned to this VLAN".format(vlan))
+
     keys = [ (k, v) for k, v in db.cfgdb.get_table('VLAN_MEMBER') if k == 'Vlan{}'.format(vid) ]
     for k in keys:
         db.cfgdb.set_entry('VLAN_MEMBER', k, None)

tests/vlan_test.py

@@ -319,6 +319,23 @@ def test_config_vlan_add_rif_portchannel_member(self):
     def test_config_vlan_del_vlan(self):
         runner = CliRunner()
         db = Db()
+        obj = {'config_db':db.cfgdb}
+
+        # del vlan with IP
+        result = runner.invoke(config.config.commands["vlan"].commands["del"], ["1000"], obj=db)
+        print(result.exit_code)
+        print(result.output)
+        assert result.exit_code != 0
+        assert "Error: Vlan1000 can not be removed. First remove IP addresses assigned to this VLAN" in result.output
+
+        # remove vlan IP`s
+        result = runner.invoke(config.config.commands["interface"].commands["ip"].commands["remove"], ["Vlan1000", "192.168.0.1/21"], obj=obj)
+        print(result.exit_code, result.output)
+        assert result.exit_code != 0
+
+        result = runner.invoke(config.config.commands["interface"].commands["ip"].commands["remove"], ["Vlan1000", "fc02:1000::1/64"], obj=obj)
+        print(result.exit_code, result.output)
+        assert result.exit_code != 0
 
         result = runner.invoke(config.config.commands["vlan"].commands["del"], ["1000"], obj=db)
         print(result.exit_code)