[config] Generate sysinfo as needed when override config (#2836)

ADO: 17921518

What I did
The generated Golden Config will not have knowledge of configs that are produced in run time, such as mac and platform.
Generate that info in Override Config if missing.

How I did it
Reuse the mac and platform in existing device runnning config and generate that if missing.

How to verify it
Unit test

config/main.py

@@ -1750,6 +1750,47 @@ def override_config_by(golden_config_path):
     return
 
 
+# This funtion is to generate sysinfo if that is missing in config_input.
+# It will keep the same with sysinfo in cur_config if sysinfo exists.
+# Otherwise it will modify config_input with generated sysinfo.
+def generate_sysinfo(cur_config, config_input, ns=None):
+    # Generate required sysinfo for Golden Config.
+    device_metadata = config_input.get('DEVICE_METADATA')
+
+    if not device_metadata or 'localhost' not in device_metadata:
+        return
+
+    mac = None
+    platform = None
+    cur_device_metadata = cur_config.get('DEVICE_METADATA')
+
+    # Reuse current config's mac and platform. Generate if absent
+    if cur_device_metadata is not None:
+        mac = cur_device_metadata.get('localhost', {}).get('mac')
+        platform = cur_device_metadata.get('localhost', {}).get('platform')
+
+    if not mac:
+        if ns:
+            asic_role = device_metadata.get('localhost', {}).get('sub_role')
+            switch_type = device_metadata.get('localhost', {}).get('switch_type')
+
+            if ((switch_type is not None and switch_type.lower() == "chassis-packet") or
+                    (asic_role is not None and asic_role.lower() == "backend")):
+                mac = device_info.get_system_mac(namespace=ns)
+            else:
+                mac = device_info.get_system_mac()
+        else:
+            mac = device_info.get_system_mac()
+
+    if not platform:
+        platform = device_info.get_platform()
+
+    device_metadata['localhost']['mac'] = mac
+    device_metadata['localhost']['platform'] = platform
+
+    return
+
+
 #
 # 'override-config-table' command ('config override-config-table ...')
 #
@@ -1791,6 +1832,8 @@ def override_config_table(db, input_config_db, dry_run):
                 ns_config_input = config_input["localhost"]
             else:
                 ns_config_input = config_input[ns]
+            # Generate sysinfo if missing in ns_config_input
+            generate_sysinfo(current_config, ns_config_input, ns)
         else:
             ns_config_input = config_input
         updated_config = update_config(current_config, ns_config_input)

tests/config_override_input/multi_asic_dm_gen_sysinfo.json

@@ -0,0 +1,55 @@
+{
+    "localhost": {
+        "DEVICE_METADATA": {
+            "localhost": {
+                "default_bgp_status": "down",
+                "default_pfcwd_status": "enable",
+                "deployment_id": "1",
+                "docker_routing_config_mode": "separated",
+                "hostname": "sonic-switch",
+                "hwsku": "Mellanox-SN3800-D112C8",
+                "peer_switch": "sonic-switch",
+                "type": "ToRRouter",
+                "suppress-fib-pending": "enabled"
+            }
+        }
+    },
+    "asic0": {
+        "DEVICE_METADATA": {
+            "localhost": {
+                "asic_id": "01.00.0",
+                "asic_name": "asic0",
+                "bgp_asn": "65100",
+                "cloudtype": "None",
+                "default_bgp_status": "down",
+                "default_pfcwd_status": "enable",
+                "deployment_id": "None",
+                "docker_routing_config_mode": "separated",
+                "hostname": "sonic",
+                "hwsku": "multi_asic",
+                "region": "None",
+                "sub_role": "FrontEnd",
+                "type": "LeafRouter"
+            }
+        }
+    },
+    "asic1": {
+        "DEVICE_METADATA": {
+            "localhost": {
+                "asic_id": "08:00.0",
+                "asic_name": "asic1",
+                "bgp_asn": "65100",
+                "cloudtype": "None",
+                "default_bgp_status": "down",
+                "default_pfcwd_status": "enable",
+                "deployment_id": "None",
+                "docker_routing_config_mode": "separated",
+                "hostname": "sonic",
+                "hwsku": "multi_asic",
+                "region": "None",
+                "sub_role": "BackEnd",
+                "type": "LeafRouter"
+            }
+        }
+    }
+}

tests/config_override_test.py

@@ -23,6 +23,7 @@
 FINAL_CONFIG_YANG_FAILURE = os.path.join(DATA_DIR, "final_config_yang_failure.json")
 MULTI_ASIC_MACSEC_OV = os.path.join(DATA_DIR, "multi_asic_macsec_ov.json")
 MULTI_ASIC_DEVICE_METADATA_RM = os.path.join(DATA_DIR, "multi_asic_dm_rm.json")
+MULTI_ASIC_DEVICE_METADATA_GEN_SYSINFO = os.path.join(DATA_DIR, "multi_asic_dm_gen_sysinfo.json")
 
 # Load sonic-cfggen from source since /usr/local/bin/sonic-cfggen does not have .py extension.
 sonic_cfggen = load_module_from_source('sonic_cfggen', '/usr/local/bin/sonic-cfggen')
@@ -318,6 +319,68 @@ def read_json_file_side_effect(filename):
         for ns, config_db in cfgdb_clients.items():
             assert 'DEVICE_METADATA' not in config_db.get_config()
 
+    def test_device_metadata_keep_sysinfo(self):
+        def read_json_file_side_effect(filename):
+            with open(MULTI_ASIC_DEVICE_METADATA_GEN_SYSINFO, "r") as f:
+                device_metadata = json.load(f)
+            return device_metadata
+        db = Db()
+        cfgdb_clients = db.cfgdb_clients
+
+        # Save original sysinfo in dict, compare later to see if it is override
+        orig_sysinfo = {}
+        for ns, config_db in cfgdb_clients.items():
+            platform = config_db.get_config()['DEVICE_METADATA']['localhost'].get('platform')
+            mac = config_db.get_config()['DEVICE_METADATA']['localhost'].get('mac')
+            orig_sysinfo[ns] = {}
+            orig_sysinfo[ns]['platform'] = platform
+            orig_sysinfo[ns]['mac'] = mac
+
+        with mock.patch('config.main.read_json_file',
+                mock.MagicMock(side_effect=read_json_file_side_effect)):
+            runner = CliRunner()
+            result = runner.invoke(config.config.commands["override-config-table"],
+                                   ['golden_config_db.json'], obj=db)
+            assert result.exit_code == 0
+
+        for ns, config_db in cfgdb_clients.items():
+            platform = config_db.get_config()['DEVICE_METADATA']['localhost'].get('platform')
+            mac = config_db.get_config()['DEVICE_METADATA']['localhost'].get('mac')
+            assert platform == orig_sysinfo[ns]['platform']
+            assert mac == orig_sysinfo[ns]['mac']
+
+    def test_device_metadata_gen_sysinfo(self):
+        def read_json_file_side_effect(filename):
+            with open(MULTI_ASIC_DEVICE_METADATA_GEN_SYSINFO, "r") as f:
+                device_metadata = json.load(f)
+            return device_metadata
+        db = Db()
+        cfgdb_clients = db.cfgdb_clients
+
+        # Remove original sysinfo and check if use generated ones
+        for ns, config_db in cfgdb_clients.items():
+            metadata = config_db.get_config()['DEVICE_METADATA']['localhost']
+            metadata.pop('platform', None)
+            metadata.pop('mac', None)
+            config_db.set_entry('DEVICE_METADATA', 'localhost', metadata)
+
+        with mock.patch('config.main.read_json_file',
+                        mock.MagicMock(side_effect=read_json_file_side_effect)),\
+                mock.patch('sonic_py_common.device_info.get_platform',
+                        return_value="multi_asic"),\
+                mock.patch('sonic_py_common.device_info.get_system_mac',
+                        return_value="11:22:33:44:55:66"):
+            runner = CliRunner()
+            result = runner.invoke(config.config.commands["override-config-table"],
+                                   ['golden_config_db.json'], obj=db)
+            assert result.exit_code == 0
+
+        for ns, config_db in cfgdb_clients.items():
+            platform = config_db.get_config()['DEVICE_METADATA']['localhost'].get('platform')
+            mac = config_db.get_config()['DEVICE_METADATA']['localhost'].get('mac')
+            assert platform == "multi_asic"
+            assert mac == "11:22:33:44:55:66"
+
 
     @classmethod
     def teardown_class(cls):