Merge pull request #29 from kytos-ng/feature/force_option_handled_err

[Feature] Added more logs when pushing flows, `force` option and retries

CHANGELOG.rst

@@ -24,6 +24,15 @@ Security
 ========
 
 
+[1.2.0] - 2021-12-13
+********************
+Changed
+=======
+- Added support for retries when sending a request to ``flow_manager``
+- Parametrized ``force`` option as a fallback
+- Added more logs for request errors
+
+
 [1.1.1] - 2021-04-22
 ********************
 Changed

kytos.json

@@ -3,7 +3,7 @@
   "username": "kytos",
   "name": "of_lldp",
   "description": "Discover network-to-network interfaces (NNIs) using the LLDP protocol.",
-  "version": "1.1.1",
+  "version": "1.2.0",
   "napp_dependencies": ["kytos/of_core", "kytos/flow_manager", "kytos/topology"],
   "license": "MIT",
   "url": "https://github.com/kytos/of_lldp.git",

main.py

@@ -1,5 +1,6 @@
 """NApp responsible to discover new switches and hosts."""
 import struct
+import time
 
 import requests
 from flask import jsonify, request
@@ -115,6 +116,15 @@ def handle_lldp_flows(self, event):
             event (:class:`~kytos.core.events.KytosEvent`):
                 Event with new switch information.
 
+        """
+        self._handle_lldp_flows(event)
+
+    def _handle_lldp_flows(self, event):
+        """Install or remove flows in a switch.
+
+        Install a flow to send LLDP packets to the controller. The proactive
+        flow is installed whenever a switch is enabled. If the switch is
+        disabled the flow is removed.
         """
         try:
             dpid = event.content['dpid']
@@ -124,15 +134,45 @@ def handle_lldp_flows(self, event):
         except AttributeError:
             of_version = None
 
+        def _retry_if_status_code(response, endpoint, data, status_codes,
+                                  retries=3, wait=2):
+            """Retry if the response is in the status_codes."""
+            if response.status_code not in status_codes:
+                return
+            if retries - 1 <= 0:
+                return
+            data = dict(data)
+            data["force"] = True
+            res = requests.post(endpoint, json=data)
+            method = res.request.method
+            if res.status_code != 202:
+                log.error(f"Failed to retry on {endpoint}, error: {res.text},"
+                          f" status: {res.status_code}, method: {method},"
+                          f" data: {data}")
+                time.sleep(wait)
+                return _retry_if_status_code(response, endpoint, data,
+                                             status_codes, retries - 1, wait)
+            log.info(f"Successfully forced {method} flows to {endpoint}")
+
         flow = self._build_lldp_flow(of_version)
         if flow:
             destination = switch.id
             endpoint = f'{settings.FLOW_MANAGER_URL}/flows/{destination}'
             data = {'flows': [flow]}
             if event.name == 'kytos/topology.switch.enabled':
-                requests.post(endpoint, json=data)
+                res = requests.post(endpoint, json=data)
+                if res.status_code != 202:
+                    log.error(f"Failed to push flows on {destination},"
+                              f" error: {res.text}, status: {res.status_code},"
+                              f" data: {data}")
+                _retry_if_status_code(res, endpoint, data, [424, 500])
             else:
-                requests.delete(endpoint, json=data)
+                res = requests.delete(endpoint, json=data)
+                if res.status_code != 202:
+                    log.error(f"Failed to delete flows on {destination},"
+                              f" error: {res.text}, status: {res.status_code}",
+                              f" data: {data}")
+                _retry_if_status_code(res, endpoint, data, [424, 500])
 
     @listen_to('kytos/of_core.v0x0[14].messages.in.ofpt_packet_in')
     def notify_uplink_detected(self, event):

setup.cfg

@@ -3,7 +3,7 @@ exclude = .eggs,ENV,build,docs/conf.py,venv
 
 [yala]
 radon mi args = --min C
-pylint args = --disable=too-many-locals,too-few-public-methods,too-many-instance-attributes --ignored-modules=napps.kytos.of_lldp
+pylint args = --disable=too-many-locals,too-few-public-methods,too-many-instance-attributes,too-many-arguments,inconsistent-return-statements --ignored-modules=napps.kytos.of_lldp
 
 [pydocstyle]
 add-ignore = D105

setup.py

@@ -22,7 +22,7 @@
 BASE_ENV = Path(os.environ.get('VIRTUAL_ENV', '/'))
 
 NAPP_NAME = 'of_lldp'
-NAPP_VERSION = '1.1.1'
+NAPP_VERSION = '1.2.0'
 
 # Kytos var folder
 VAR_PATH = BASE_ENV / 'var' / 'lib' / 'kytos'

tests/unit/test_main.py

@@ -81,6 +81,24 @@ def test_handle_lldp_flows(self, mock_post, mock_delete):
         self.napp.handle_lldp_flows(event_del)
         mock_delete.assert_called()
 
+    @patch("time.sleep")
+    @patch("requests.post")
+    def test_handle_lldp_flows_retries(self, mock_post, _):
+        """Test handle_lldp_flow method retries."""
+        dpid = "00:00:00:00:00:00:00:01"
+        switch = get_switch_mock("00:00:00:00:00:00:00:01", 0x04)
+        self.napp.controller.switches = {dpid: switch}
+        event_post = get_kytos_event_mock(name="kytos/topology.switch.enabled",
+                                          content={"dpid": dpid})
+
+        mock = MagicMock()
+        mock.request.method = "POST"
+        mock.status_code = 500
+        mock.text = "some_err"
+        mock_post.return_value = mock
+        self.napp._handle_lldp_flows(event_post)
+        self.assertTrue(mock_post.call_count, 3)
+
     @patch('kytos.core.buffers.KytosEventBuffer.put')
     @patch('napps.kytos.of_lldp.main.KytosEvent')
     @patch('kytos.core.controller.Controller.get_switch_by_dpid')