Support update link on controller

Ref https://github.com/GNS3/gns3-gui/issues/1300

gns3server/controller/link.py

@@ -43,18 +43,38 @@ class Link:
         self._streaming_pcap = None
 
     @asyncio.coroutine
-    def add_node(self, node, adapter_number, port_number):
+    def add_node(self, node, adapter_number, port_number, label=None):
         """
         Add a node to the link
         """
+
+        if label is None:
+            label = {
+                "x": -10,
+                "y": -10,
+                "text": "{}/{}".format(adapter_number, port_number),
+                "style": "font-size: 10; font-style: Verdana"
+            }
+
         self._nodes.append({
             "node": node,
             "adapter_number": adapter_number,
-            "port_number": port_number
+            "port_number": port_number,
+            "label": label
         })
 
         if len(self._nodes) == 2:
             self._project.controller.notification.emit("link.created", self.__json__())
+
+        self._project.dump()
+
+    @asyncio.coroutine
+    def update_node(self, node, adapter_number, port_number, label=None):
+        for port in self._nodes:
+            if port["node"] == node:
+                if label:
+                    port["label"] = label
+        self._project.controller.notification.emit("link.updated", self.__json__())
         self._project.dump()
 
     @asyncio.coroutine
@@ -166,7 +186,8 @@ class Link:
             res.append({
                 "node_id": side["node"].id,
                 "adapter_number": side["adapter_number"],
-                "port_number": side["port_number"]
+                "port_number": side["port_number"],
+                "label": side["label"]
             })
         if topology_dump:
             return {

gns3server/handlers/api/controller/link_handler.py

@@ -66,11 +66,38 @@ class LinkHandler:
         for node in request.json["nodes"]:
             yield from link.add_node(project.get_node(node["node_id"]),
                                      node.get("adapter_number", 0),
-                                     node.get("port_number", 0))
+                                     node.get("port_number", 0),
+                                     label=node.get("label"))
         yield from link.create()
         response.set_status(201)
         response.json(link)
 
+    @Route.put(
+        r"/projects/{project_id}/links/{link_id}",
+        parameters={
+            "project_id": "Project UUID",
+            "link_id": "Link UUID"
+        },
+        status_codes={
+            201: "Link updated",
+            400: "Invalid request"
+        },
+        description="Update a link instance",
+        input=LINK_OBJECT_SCHEMA,
+        output=LINK_OBJECT_SCHEMA)
+    def update(request, response):
+
+        controller = Controller.instance()
+        project = controller.get_project(request.match_info["project_id"])
+        link = project.get_link(request.match_info["link_id"])
+        for node in request.json["nodes"]:
+            yield from link.update_node(project.get_node(node["node_id"]),
+                                     node.get("adapter_number", 0),
+                                     node.get("port_number", 0),
+                                     label=node.get("label"))
+        response.set_status(201)
+        response.json(link)
+
     @Route.post(
         r"/projects/{project_id}/links/{link_id}/start_capture",
         parameters={

gns3server/schemas/link.py

@@ -15,6 +15,8 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
+from .label import LABEL_OBJECT_SCHEMA
+
 
 LINK_OBJECT_SCHEMA = {
     "$schema": "http://json-schema.org/draft-04/schema#",
@@ -55,7 +57,8 @@ LINK_OBJECT_SCHEMA = {
                     "port_number": {
                         "description": "Port number",
                         "type": "integer"
-                    }
+                    },
+                    "label": LABEL_OBJECT_SCHEMA
                 },
                 "required": ["node_id", "adapter_number", "port_number"],
                 "additionalProperties": False