Change how EVCs are loaded on startup

Instead of always trying to deploy EVCs on startup,
verify first if the old path is installed in the switches
and working. Fix kytos#33.

main.py

@@ -2,6 +2,7 @@
 
 NApp to provision circuits from user request.
 """
+import time
 from threading import Lock
 
 from flask import jsonify, request
@@ -54,14 +55,20 @@ def setup(self):
         self._lock = Lock()
 
         self.execute_as_loop(settings.DEPLOY_EVCS_INTERVAL)
+        self.load_time = time.time()
         self.load_all_evcs()
 
     def execute(self):
         """Execute once when the napp is running."""
         for circuit in tuple(self.circuits.values()):
             if circuit.is_enabled() and not circuit.is_active():
-                with circuit.lock:
-                    circuit.deploy()
+                if circuit.check_traces():
+                    circuit.activate()
+                    circuit.sync()
+                else:
+                    running_for = time.time() - self.load_time
+                    if running_for > settings.WAIT_FOR_OLD_PATH:
+                        circuit.deploy()
 
     def shutdown(self):
         """Execute when your napp is unloaded.
@@ -592,7 +599,6 @@ def _load_evc(self, circuit_dict):
         if evc.archived:
             return None
         evc.deactivate()
-        evc.current_path = Path([])
         evc.sync()
         self.circuits.setdefault(evc.id, evc)
         self.sched.add(evc)

models.py

@@ -12,6 +12,7 @@
 from kytos.core.helpers import get_time, now
 from kytos.core.interface import UNI
 from kytos.core.link import Link
+
 from napps.kytos.mef_eline import settings
 from napps.kytos.mef_eline.exceptions import FlowModException
 from napps.kytos.mef_eline.storehouse import StoreHouse

requirements/run.in

@@ -1,2 +1,3 @@
 apscheduler
 requests
+glom

settings.py

@@ -15,5 +15,8 @@
 # EVC consistency interval
 DEPLOY_EVCS_INTERVAL = 60
 
+# Time to wait for old path to become available
+WAIT_FOR_OLD_PATH = 5 * DEPLOY_EVCS_INTERVAL
+
 # Prefix this NApp has when using cookies
 COOKIE_PREFIX = 0xaa

tests/unit/models/test_link_protection.py

@@ -196,6 +196,7 @@ def test_handle_link_down_case_1(self, path_status_mocked,
         evc = EVC(**attributes)
 
         evc.current_path = evc.primary_path
+        evc.activate()
         current_handle_link_down = evc.handle_link_down()
         self.assertEqual(deploy_mocked.call_count, 0)
         deploy_to_mocked.assert_called_once()