[multi-asic][cli][chassis-db] Avoid connecting to chassis db when cli commands are executed from linecards

src/sonic-py-common/sonic_py_common/device_info.py

@@ -29,6 +29,7 @@
 NPU_NAME_PREFIX = "asic"
 NAMESPACE_PATH_GLOB = "/run/netns/*"
 ASIC_CONF_FILENAME = "asic.conf"
+PLATFORM_ENV_CONF_FILENAME = "platform_env.conf"
 FRONTEND_ASIC_SUB_ROLE = "FrontEnd"
 BACKEND_ASIC_SUB_ROLE = "BackEnd"
 
@@ -164,6 +165,29 @@ def get_asic_conf_file_path():
     return None
 
 
+def get_platform_env_conf_file_path():
+    """
+    Retrieves the path to the PLATFORM ENV conguration file on the device
+
+    Returns:
+        A string containing the path to the PLATFORM ENV conguration file on success,
+        None on failure
+    """
+    platform_env_conf_path_candidates = []
+
+    platform_env_conf_path_candidates.append(os.path.join(CONTAINER_PLATFORM_PATH, PLATFORM_ENV_CONF_FILENAME))
+
+    platform = get_platform()
+    if platform:
+        platform_env_conf_path_candidates.append(os.path.join(HOST_DEVICE_PATH, platform, PLATFORM_ENV_CONF_FILENAME))
+
+    for platform_env_conf_file_path in platform_env_conf_path_candidates:
+        if os.path.isfile(platform_env_conf_file_path):
+            return platform_env_conf_file_path
+
+    return None
+
+
 def get_path_to_platform_dir():
     """
     Retreives the paths to the device's platform directory
@@ -374,6 +398,22 @@ def is_multi_npu():
     return (num_npus > 1)
 
 
+def is_supervisor():
+    platform_env_conf_file_path = get_platform_env_conf_file_path()
+    if platform_env_conf_file_path is None:
+        return False
+    with open(platform_env_conf_file_path) as platform_env_conf_file:
+        for line in platform_env_conf_file:
+            tokens = line.split('=')
+            if len(tokens) < 2:
+               continue
+            if tokens[0].lower() == 'supervisor':
+                val = tokens[1].strip()
+                if val == '1':
+                    return True
+        return False
+
+
 def get_npu_id_from_name(npu_name):
     if npu_name.startswith(NPU_NAME_PREFIX):
         return npu_name[len(NPU_NAME_PREFIX):]

src/sonic-py-common/sonic_py_common/multi_asic.py

@@ -8,6 +8,7 @@
 from .device_info import CONTAINER_PLATFORM_PATH
 from .device_info import HOST_DEVICE_PATH
 from .device_info import get_platform
+from .device_info import is_supervisor
 
 ASIC_NAME_PREFIX = 'asic'
 NAMESPACE_PATH_GLOB = '/run/netns/*'
@@ -45,7 +46,11 @@ def connect_config_db_for_ns(namespace=DEFAULT_NAMESPACE):
 def connect_to_all_dbs_for_ns(namespace=DEFAULT_NAMESPACE):
     """
     The function connects to the DBs for a given namespace and
-    returns the handle
+    returns the handle 
+
+    For voq chassis systems, the db list includes databases from 
+    supervisor card. Avoid connecting to these databases from linecards
+
     If no namespace is provided, it will connect to the db in the
     default namespace.
     In case of multi ASIC, the default namespace is the
@@ -56,7 +61,15 @@ def connect_to_all_dbs_for_ns(namespace=DEFAULT_NAMESPACE):
         handle to all the dbs for a namespaces
     """
     db = swsscommon.SonicV2Connector(namespace=namespace)
-    for db_id in db.get_db_list():
+    db_list = list(db.get_db_list())
+    if not is_supervisor():
+        try:
+            db_list.remove('CHASSIS_APP_DB')
+            db_list.remove('CHASSIS_STATE_DB')
+        except Exception:
+            pass
+
+    for db_id in db_list:
         db.connect(db_id)
     return db