Add archived connection API

sdx_controller/controllers/l2vpn_controller.py

@@ -219,5 +219,20 @@ def patch_connection(service_id, body=None):  # noqa: E501
 
     return response, code
 
+
 def get_archived_connections_by_id(service_id):
-    return "Do some magic"
+    """
+    List archived connection by ID.
+
+    :param service_id: ID of connection that needs to be fetched
+    :type service_id: str
+
+    :rtype: Connection
+    """
+
+    value = get_connection_status(db_instance, service_id)
+
+    if not value:
+        return "Connection not found", 404
+
+    return value

sdx_controller/handlers/connection_handler.py

@@ -271,6 +271,14 @@ def handle_link_failure(self, te_manager, failed_links):
                     logger.debug(connection)
                     self.place_connection(te_manager, connection)
 
+    def get_archived_connections(self, service_id: str):
+        historical_connections = self.db_instance.read_from_db(
+            "historical_connections", service_id
+        )
+        if not historical_connections:
+            return None
+        return historical_connections[service_id]
+
 
 def get_connection_status(db, service_id: str):
     """