[dhcp_server] add config dhcp server del (#17603)

* add config dhcp server del

dockers/docker-dhcp-server/cli-plugin-tests/conftest.py

@@ -62,10 +62,19 @@ def mock_db():
         if table == "STATE_DB":
             return key in mock_state_db
 
+    def delete(table, key):
+        assert table == "CONFIG_DB" or table == "STATE_DB"
+        if table == "CONFIG_DB":
+            del mock_config_db[key]
+        if table == "STATE_DB":
+            del mock_state_db[key]
+
+
     db.keys = mock.Mock(side_effect=keys)
     db.get_all = mock.Mock(side_effect=get_all)
     db.get = mock.Mock(side_effect=get)
     db.hmset = mock.Mock(side_effect=hmset)
     db.exists = mock.Mock(side_effect=exists)
+    db.delete = mock.Mock(side_effect=delete)
 
     yield db

dockers/docker-dhcp-server/cli-plugin-tests/test_config_dhcp_server.py

@@ -113,3 +113,18 @@ class TestConfigDHCPServer(object):
                 ["Vlan100", "--mode=PORT", "--lease_time=1000", "--gateway=10.10.10.10", "--netmask=255.255.254.0"], obj=db)
         assert result.exit_code == 2, "exit code: {}, Exception: {}, Traceback: {}".format(result.exit_code, result.exception, result.exc_info)
 
+    def test_config_dhcp_server_ipv4_del_already_exist(self, mock_db):
+        runner = CliRunner()
+        db = clicommon.Db()
+        db.db = mock_db
+        result = runner.invoke(dhcp_server.dhcp_server.commands["ipv4"].commands["del"], ["Vlan100"], obj=db)
+        assert result.exit_code == 0, "exit code: {}, Exception: {}, Traceback: {}".format(result.exit_code, result.exception, result.exc_info)
+        assert mock_db.exists("CONFIG_DB", "DHCP_SERVER_IPV4|Vlan100") == False
+
+    def test_config_dhcp_server_ipv4_del_does_not_exist(self, mock_db):
+        runner = CliRunner()
+        db = clicommon.Db()
+        db.db = mock_db
+        result = runner.invoke(dhcp_server.dhcp_server.commands["ipv4"].commands["del"], ["Vlan200"], obj=db)
+        assert result.exit_code == 2, "exit code: {}, Exception: {}, Traceback: {}".format(result.exit_code, result.exception, result.exc_info)
+

dockers/docker-dhcp-server/cli/config/plugins/dhcp_server.py

@@ -102,6 +102,20 @@ def dhcp_server_ipv4_add(db, mode, lease_time, dup_gw_nm, gateway, netmask, dhcp
             })
 
 
+@dhcp_server_ipv4.command(name="del")
+@click.argument("dhcp_interface", required=True)
+@clicommon.pass_db
+def dhcp_server_ipv4_del(db, dhcp_interface):
+    ctx = click.get_current_context()
+    dbconn = db.db
+    key = "DHCP_SERVER_IPV4|" + dhcp_interface
+    if dbconn.exists("CONFIG_DB", key):
+        click.echo("Dhcp interface %s exists in config db, proceed to delete".format(dhcp_interface))
+        dbconn.delete("CONFIG_DB", key)
+    else:
+        ctx.fail("Dhcp interface %s does not exist in config db".format(dhcp_interface))
+
+
 def register(cli):
     # cli.add_command(dhcp_server)
     pass