[sonic-py-common] Relocate some functions from sonic-utilities (#5269)

* Relocate interface related common functions to py-common
* Add unit tests for interface API's.

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

@@ -1,3 +1,7 @@
+"""
+SONiC interface types and access functions.
+"""
+
 """
  Dictionary of SONIC interface name prefixes. Each entry in the format
  "Human readable interface string":"Sonic interface prefix"
@@ -12,6 +16,8 @@ SONIC_INTERFACE_PREFIXES = {
     "Ethernet-Backplane": "Ethernet-BP"
 }
 
+VLAN_SUB_INTERFACE_SEPARATOR = '.'
+
 def front_panel_prefix():
     """
     Retrieves the SONIC front panel interface name prefix.
@@ -41,3 +47,39 @@ def loopback_prefix():
     Retrieves the SONIC Loopback interface name prefix.
     """
     return SONIC_INTERFACE_PREFIXES["Loopback"]
+
+def get_interface_table_name(interface_name):
+    """Get table name by interface_name prefix
+    """
+    if interface_name.startswith(front_panel_prefix()):
+        if VLAN_SUB_INTERFACE_SEPARATOR in interface_name:
+            return "VLAN_SUB_INTERFACE"
+        return "INTERFACE"
+    elif interface_name.startswith(portchannel_prefix()):
+        if VLAN_SUB_INTERFACE_SEPARATOR in interface_name:
+            return "VLAN_SUB_INTERFACE"
+        return "PORTCHANNEL_INTERFACE"
+    elif interface_name.startswith(vlan_prefix()):
+        return "VLAN_INTERFACE"
+    elif interface_name.startswith(loopback_prefix()):
+        return "LOOPBACK_INTERFACE"
+    else:
+        return ""
+
+def get_port_table_name(interface_name):
+    """Get table name by port_name prefix
+    """
+    if interface_name.startswith(front_panel_prefix()):
+        if VLAN_SUB_INTERFACE_SEPARATOR in interface_name:
+            return "VLAN_SUB_INTERFACE"
+        return "PORT"
+    elif interface_name.startswith(portchannel_prefix()):
+        if VLAN_SUB_INTERFACE_SEPARATOR in interface_name:
+            return "VLAN_SUB_INTERFACE"
+        return "PORTCHANNEL"
+    elif interface_name.startswith(vlan_prefix()):
+        return "VLAN_INTERFACE"
+    elif interface_name.startswith(loopback_prefix()):
+        return "LOOPBACK_INTERFACE"
+    else:
+        return ""

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

@@ -372,3 +372,15 @@ def get_asic_index_from_namespace(namespace):
         return int(get_asic_id_from_name(namespace))
 
     return 0
+
+# Validate whether a given namespace name is valid in the device.
+# This API is significant in multi-asic platforms.
+def validate_namespace(namespace):
+    if not is_multi_asic():
+        return True
+
+    namespaces = get_all_namespaces()
+    if namespace in namespaces['front_ns'] + namespaces['back_ns']:
+        return True
+    else:
+        return False

src/sonic-py-common/tests/interface_test.py

@@ -0,0 +1,41 @@
+import os
+import sys
+
+from sonic_py_common import interface
+
+class TestInterface(object):
+    @classmethod
+    def setup_class(cls):
+        print("SETUP")
+
+    def test_get_interface_table_name(self):
+        result = interface.get_interface_table_name("Ethernet0")
+        assert result == "INTERFACE"
+        result = interface.get_interface_table_name("Ethernet0.100")
+        assert result == "VLAN_SUB_INTERFACE"
+        result = interface.get_interface_table_name("PortChannel0")
+        assert result == "PORTCHANNEL_INTERFACE"
+        result = interface.get_interface_table_name("PortChannel0.100")
+        assert result == "VLAN_SUB_INTERFACE"
+        result = interface.get_interface_table_name("Vlan100")
+        assert result == "VLAN_INTERFACE"
+        result = interface.get_interface_table_name("Loopback0")
+        assert result == "LOOPBACK_INTERFACE"
+
+    def test_get_port_table_name(self):
+        result = interface.get_port_table_name("Ethernet0")
+        assert result == "PORT"
+        result = interface.get_port_table_name("Ethernet0.100")
+        assert result == "VLAN_SUB_INTERFACE"
+        result = interface.get_port_table_name("PortChannel0")
+        assert result == "PORTCHANNEL"
+        result = interface.get_port_table_name("PortChannel0.100")
+        assert result == "VLAN_SUB_INTERFACE"
+        result = interface.get_port_table_name("Vlan100")
+        assert result == "VLAN_INTERFACE"
+        result = interface.get_port_table_name("Loopback0")
+        assert result == "LOOPBACK_INTERFACE"
+
+    @classmethod
+    def teardown_class(cls):
+        print("TEARDOWN")