[sonic-mpls-tc-map.yang]: yang model for mpls_tc_to_tc_map table. (#12176)

changes:
  -- yang model for mpls_tc_to_tc_map table.
  -- tests.

#### Why I did it
yang model for mpls_tc_to_tc_map table.

#### How I did it
-- yang model for mpls_tc_to_tc_map table.
-- yang model tests.

#### How to verify it
-- yang model build time tests.

src/sonic-yang-mgmt/sonic_yang_ext.py

@@ -17,7 +17,8 @@ Type_1_list_maps_model = [
     'PFC_PRIORITY_TO_PRIORITY_GROUP_MAP_LIST',
     'DSCP_TO_FC_MAP_LIST',
     'EXP_TO_FC_MAP_LIST',
-    'CABLE_LENGTH_LIST'
+    'CABLE_LENGTH_LIST',
+    'MPLS_TC_TO_TC_MAP_LIST'
 ]
 
 # Workaround for those fields who is defined as leaf-list in YANG model but have string value in config DB.
@@ -422,7 +423,7 @@ class SonicYangExtMixin:
             vValue = list()
             if isinstance(value, str) and (self.elementPath[0], self.elementPath[-1]) in LEAF_LIST_WITH_STRING_VALUE_DICT:
                 # For field defined as leaf-list but has string value in CONFIG DB, need do special handling here. For exampe:
-                # port.adv_speeds in CONFIG DB has value "100,1000,10000", it shall be transferred to [100,1000,10000] as YANG value here to 
+                # port.adv_speeds in CONFIG DB has value "100,1000,10000", it shall be transferred to [100,1000,10000] as YANG value here to
                 # make it align with its YANG definition.
                 value = (x.strip() for x in value.split(LEAF_LIST_WITH_STRING_VALUE_DICT[(self.elementPath[0], self.elementPath[-1])]))
             for v in value:

src/sonic-yang-models/setup.py

@@ -117,6 +117,7 @@ setup(
                          './yang-models/sonic-mgmt_port.yang',
                          './yang-models/sonic-mgmt_vrf.yang',
                          './yang-models/sonic-mirror-session.yang',
+                         './yang-models/sonic-mpls-tc-map.yang',
                          './yang-models/sonic-mux-cable.yang',
                          './yang-models/sonic-ntp.yang',
                          './yang-models/sonic-nat.yang',

src/sonic-yang-models/tests/files/sample_config_db.json

@@ -830,7 +830,7 @@
                 "role": "Int",
                 "speed": "40000",
                 "tpid": "0x8100"
-            } 
+            }
         },
         "ACL_TABLE": {
             "V4-ACL-TABLE": {
@@ -1680,6 +1680,17 @@
             }
         },
 
+        "MPLS_TC_TO_TC_MAP": {
+           "Mpls_tc_to_tc_map1": {
+              "1": "1",
+              "3":  "2"
+            },
+           "Mpls_tc_to_tc_map2": {
+              "2": "3",
+              "4": "4"
+            }
+        },
+
         "DOT1P_TO_TC_MAP": {
            "Dot1p_to_tc_map1": {
               "1": "1",
@@ -1831,7 +1842,7 @@
                 "server_ipv6": "fc02:1000::30/128",
                 "soc_ipv4": "192.168.0.3/32",
                 "state": "auto"
-            }, 
+            },
             "Ethernet0": {
                 "server_ipv4": "192.168.0.2/32",
                 "server_ipv6": "fc02:1000::30/128",

src/sonic-yang-models/tests/yang_model_tests/tests/mpls_tc_to_tc_map.json

@@ -0,0 +1,11 @@
+{
+    "MPLS_TCP_MAP_INCORRECT_MPLS_PATTERN": {
+        "desc": "Configure INCORRECT_MPLS_PATTERN in MPLS_TCP_MAP Table.",
+        "eStr": ["Invalid MPLS"]
+
+    },
+    "MPLS_TCP_MAP_INCORRECT_TC_PATTERN": {
+        "desc": "Configure INCORRECT_TC_PATTERN in MPLS_TCP_MAP Table.",
+        "eStr": ["Invalid Traffic Class"]
+    }
+}

src/sonic-yang-models/tests/yang_model_tests/tests_config/mpls_tc_to_tc_map.json

@@ -0,0 +1,36 @@
+{
+    "MPLS_TCP_MAP_INCORRECT_MPLS_PATTERN": {
+        "sonic-mpls-tc-map:sonic-mpls-tc-map": {
+            "sonic-mpls-tc-map:MPLS_TC_TO_TC_MAP": {
+                "MPLS_TC_TO_TC_MAP_LIST": [
+                    {
+                        "name": "Mpls_tc_to_tc_map1",
+                        "MPLS_TC_TO_TC_MAP": [
+                            {
+                                "mpls": "8",
+                                "tc": "1"
+                            }
+                        ]
+                    }
+                ]
+            }
+        }
+    },
+    "MPLS_TCP_MAP_INCORRECT_TC_PATTERN": {
+        "sonic-mpls-tc-map:sonic-mpls-tc-map": {
+            "sonic-mpls-tc-map:MPLS_TC_TO_TC_MAP": {
+                "MPLS_TC_TO_TC_MAP_LIST": [
+                    {
+                        "name": "Mpls_tc_to_tc_map2",
+                        "MPLS_TC_TO_TC_MAP": [
+                            {
+                                "mpls": "1",
+                                "tc": "16"
+                            }
+                        ]
+                    }
+                ]
+            }
+        }
+    }
+}

src/sonic-yang-models/yang-models/sonic-mpls-tc-map.yang

@@ -0,0 +1,70 @@
+module sonic-mpls-tc-map {
+
+    yang-version 1.1;
+
+    namespace "http://github.com/Azure/sonic-mpls-tc-map";
+
+    prefix mpls_tc_map;
+
+    import sonic-types {
+        prefix stypes;
+    }
+
+    organization
+        "SONiC";
+
+    contact
+        "SONiC";
+
+    description
+        "MPLS_TC_TO_TC_MAP yang Module for SONiC OS";
+
+    revision 2021-04-15 {
+        description
+            "Initial revision.";
+    }
+
+    container sonic-mpls-tc-map {
+
+        container MPLS_TC_TO_TC_MAP {
+
+            description "MPLS_TC_TO_TC_MAP part of config_db.json";
+
+            list MPLS_TC_TO_TC_MAP_LIST {
+
+                key "name";
+
+                leaf name {
+                    description "Name of MPLS TC Mpping List";
+                    type string {
+                        pattern '[a-zA-Z0-9]{1}([-a-zA-Z0-9_]{0,31})';
+                        length 1..32 {
+                            error-message "Invalid length for map name.";
+                            error-app-tag map-name-invalid-length;
+                        }
+                    }
+                }
+
+                list MPLS_TC_TO_TC_MAP { //this is list inside list for storing mapping between two fields
+
+                    key "mpls";
+
+                    leaf mpls {
+                        description "MPLS TC Value";
+                        type string {
+                            pattern "[0-7]?" {
+                                error-message "Invalid MPLS";
+                                error-app-tag mpls-invalid;
+                            }
+                        }
+                    }
+
+                    leaf tc {
+                        description "Matching TC Value";
+                        type stypes:tc_type;
+                    }
+                }
+            }
+        }
+    }
+}