[dhcp_server] Add field not exist checks in dhcp_cfggen (#17645)

* [dhcp_server] Add field not exist checks in dhcp_cfggen

src/sonic-dhcp-utilities/dhcp_utilities/dhcpservd/dhcp_cfggen.py

@@ -134,6 +134,7 @@ class DhcpServCfgGenerator(object):
         client_classes = []
         enabled_dhcp_interfaces = set()
         used_options = set()
+        customized_option_keys = customized_options.keys()
         # Different mode would subscribe different table, always subscribe DHCP_SERVER_IPV4
         subscribe_table = set(["DhcpServerTableCfgChangeEventChecker"])
         for dhcp_interface_name, dhcp_config in dhcp_server_ipv4.items():
@@ -147,8 +148,12 @@ class DhcpServCfgGenerator(object):
                                   .format(dhcp_interface_name))
                     continue
                 curr_options = {}
-                for option in dhcp_config["customized_options"]:
+                if "customized_options" in dhcp_config:
-                    if option in customized_options.keys():
+                    for option in dhcp_config["customized_options"]:
+                        if option not in customized_option_keys:
+                            syslog.syslog(syslog.LOG_WARNING, "Customized option {} configured for {} is not defined"
+                                          .format(option, dhcp_interface_name))
+                            continue
                         curr_options[option] = {
                             "always_send": customized_options[option]["always_send"],
                             "value": customized_options[option]["value"]
@@ -352,6 +357,9 @@ class DhcpServCfgGenerator(object):
                 syslog.syslog(syslog.LOG_WARNING, f"Cannot find {splits[1]} in port_alias_map")
                 continue
             port = self.port_alias_map[splits[1]]
+            if dhcp_interface_name not in vlan_interfaces:
+                syslog.syslog(syslog.LOG_WARNING, f"Interface {dhcp_interface_name} doesn't have IPv4 address")
+                continue
             if dhcp_interface_name not in port_ips:
                 port_ips[dhcp_interface_name] = {}
             # Get ip information of Vlan

src/sonic-dhcp-utilities/tests/conftest.py

@@ -35,7 +35,8 @@ def mock_get_render_template():
 def mock_parse_port_map_alias(scope="function"):
     with patch("dhcp_utilities.dhcpservd.dhcp_cfggen.DhcpServCfgGenerator._parse_port_map_alias",
                return_value=None) as mock_map, \
-         patch.object(DhcpServCfgGenerator, "port_alias_map", return_value={"Ethernet24": "etp7", "Ethernet28": "etp8"},
+         patch.object(DhcpServCfgGenerator, "port_alias_map", return_value={"Ethernet24": "etp7", "Ethernet28": "etp8",
+                                                                            "Ethernet44": "etp12"},
                       new_callable=PropertyMock), \
          patch.object(DhcpServCfgGenerator, "lease_update_script_path", return_value="/etc/kea/lease_update.sh",
                       new_callable=PropertyMock), \

src/sonic-dhcp-utilities/tests/test_data/mock_config_db.json

@@ -6,7 +6,8 @@
     },
     "VLAN": {
         "Vlan1000": {},
-        "Vlan2000": {}
+        "Vlan2000": {},
+        "Vlan3000": {}
     },
     "VLAN_INTERFACE": {
         "Vlan1000|192.168.0.1/21": {
@@ -26,6 +27,9 @@
         },
         "Vlan2000": {
             "NULL": "NULL"
+        },
+        "Vlan3000": {
+            "NULL": "NULL"
         }
     },
     "VLAN_MEMBER": {
@@ -37,6 +41,9 @@
         },
         "Vlan1000|Ethernet40": {
             "tagging_mode": "untagged"
+        },
+        "Vlan3000|Ethernet44": {
+            "tagging_mode": "untagged"
         }
     },
     "DHCP_SERVER_IPV4": {
@@ -92,6 +99,13 @@
             "mode": "PORT",
             "netmask": "255.255.255.0",
             "state": "disabled"
+        },
+        "Vlan6000": {
+            "gateway": "192.168.2.1",
+            "lease_time": "900",
+            "mode": "PORT",
+            "netmask": "255.255.255.0",
+            "state": "enabled"
         }
     },
     "DHCP_SERVER_IPV4_RANGE": {
@@ -160,6 +174,11 @@
             "ips": [
                 "192.168.0.10"
             ]
+        },
+        "Vlan3000|Ethernet44": {
+            "ips": [
+                "192.168.0.10"
+            ]
         }
     },
     "PORT": {

src/sonic-dhcp-utilities/tests/test_dhcp_cfggen.py

@@ -303,7 +303,8 @@ def test_parse_vlan(mock_swsscommon_dbconnector_init, mock_parse_port_map_alias,
     vlan_interfaces, vlan_members = dhcp_cfg_generator._parse_vlan(mock_config_db.config_db.get("VLAN_INTERFACE"),
                                                                    mock_config_db.config_db.get("VLAN_MEMBER"))
     assert vlan_interfaces == expected_vlan_ipv4_interface
-    assert list(vlan_members) == ["Vlan1000|Ethernet24", "Vlan1000|Ethernet28", "Vlan1000|Ethernet40"]
+    expeceted_members = ["Vlan1000|Ethernet24", "Vlan1000|Ethernet28", "Vlan1000|Ethernet40", "Vlan3000|Ethernet44"]
+    assert list(vlan_members) == expeceted_members
 
 
 @pytest.mark.parametrize("test_config_db", ["mock_config_db.json", "mock_config_db_without_port_config.json"])
@@ -352,11 +353,22 @@ def test_construct_obj_for_template(mock_swsscommon_dbconnector_init, mock_parse
     customized_options = {"option223": {"id": "223", "value": "dummy_value", "type": "string", "always_send": "true"}}
     dhcp_cfg_generator = DhcpServCfgGenerator(dhcp_db_connector)
     tested_hostname = "sonic-host"
+    port_ips = {
+        "Vlan1000": {
+            "192.168.0.1/21": {
+                "etp8": [["192.168.0.2", "192.168.0.6"], ["192.168.0.10", "192.168.0.10"]],
+                "etp7": [["192.168.0.7", "192.168.0.7"]],
+                "etp9": []
+            }
+        },
+        "Vlan6000": {
+        }
+    }
     render_obj, enabled_dhcp_interfaces, used_options, subscribe_table = \
         dhcp_cfg_generator._construct_obj_for_template(mock_config_db.config_db.get("DHCP_SERVER_IPV4"),
-                                                       tested_parsed_port, tested_hostname, customized_options)
+                                                       port_ips, tested_hostname, customized_options)
     assert render_obj == expected_render_obj
-    assert enabled_dhcp_interfaces == {"Vlan1000", "Vlan4000", "Vlan3000"}
+    assert enabled_dhcp_interfaces == {"Vlan1000", "Vlan4000", "Vlan3000", "Vlan6000"}
     assert used_options == set(["option223"])
     assert subscribe_table == set(PORT_MODE_CHECKER)