[202012][BGPCfgD] Support for Static Route Expiry

src/sonic-bgpcfgd/bgpcfgd/main.py

@@ -3,6 +3,7 @@
 import sys
 import syslog
 import traceback
+import threading
 
 from swsscommon import swsscommon
 
@@ -18,6 +19,7 @@
 from .managers_setsrc import ZebraSetSrc
 from .managers_static_rt import StaticRouteMgr
 from .managers_rm import RouteMapMgr
+from .static_rt_timer import StaticRouteTimer
 from .runner import Runner, signal_handler
 from .template import TemplateFabric
 from .utils import read_constants
@@ -27,6 +29,9 @@
 
 def do_work():
     """ Main function """
+    st_rt_timer = StaticRouteTimer()
+    thr = threading.Thread(target = st_rt_timer.run)
+    thr.start()
     frr = FRR(["bgpd", "zebra", "staticd"])
     frr.wait_for_daemons(seconds=20)
     #
@@ -59,6 +64,7 @@ def do_work():
         BBRMgr(common_objs, "CONFIG_DB", "BGP_BBR"),
         # Static Route Managers
         StaticRouteMgr(common_objs, "CONFIG_DB", "STATIC_ROUTE"),
+        StaticRouteMgr(common_objs, "APPL_DB", "STATIC_ROUTE"),
         # Route Advertisement Managers
         AdvertiseRouteMgr(common_objs, "STATE_DB", swsscommon.STATE_ADVERTISE_NETWORK_TABLE_NAME),
         RouteMapMgr(common_objs, "APPL_DB", swsscommon.APP_BGP_PROFILE_TABLE_NAME),
@@ -67,6 +73,7 @@ def do_work():
     for mgr in managers:
         runner.add_manager(mgr)
     runner.run()
+    thr.join()
 
 
 def main():

src/sonic-bgpcfgd/bgpcfgd/managers_static_rt.py

@@ -94,10 +94,12 @@ def split_key(key):
         :param key: key to split
         :return: vrf name extracted from the key, ip prefix extracted from the key
         """
-        if '|' not in key:
-            return 'default', key
-        else:
+        if '|' in key:
             return tuple(key.split('|', 1))
+        elif ':' in key:
+            return tuple(key.split(':', 1))
+        else:
+            return 'default', key
 
     def static_route_commands(self, ip_nh_set, cur_nh_set, ip_prefix, vrf):
         diff_set = ip_nh_set.symmetric_difference(cur_nh_set)

src/sonic-bgpcfgd/bgpcfgd/static_rt_timer.py

@@ -0,0 +1,55 @@
+from .log import log_err, log_info, log_debug
+from swsssdk import SonicV2Connector
+import time
+
+class StaticRouteTimer(object):
+    """ This class checks the static routes and deletes those entries that have not been refreshed """
+    def __init__(self):
+        self.db = SonicV2Connector()
+        self.db.connect(self.db.APPL_DB)
+        self.timer = None
+        self.start = None
+
+    DEFAULT_TIMER = 180
+    DEFAULT_SLEEP = 60
+    MAX_TIMER     = 1800
+
+    def set_timer(self):
+        """ Check for custom route expiry time in STATIC_ROUTE:EXPIRY_TIME """
+        timer = self.db.get(self.db.APPL_DB, "STATIC_ROUTE_EXPIRY_TIME", "time")
+        if timer is not None:
+            timer = int(timer)     
+            if timer > 0 and timer <= self.MAX_TIMER:
+                self.timer = timer
+                return
+            log_err("Custom static route expiry time of {}s is invalid!".format(timer))
+        return
+
+    def alarm(self):
+        """ Clear unrefreshed static routes """
+        static_routes = self.db.keys(self.db.APPL_DB, "STATIC_ROUTE:*:*")
+        if static_routes is not None:
+            for sr in static_routes:
+                refresh = self.db.get(self.db.APPL_DB, sr, "refresh")
+                val = sr.split(":")
+                if refresh == "true":
+                    self.db.set(self.db.APPL_DB, sr, "refresh", "false")
+                    log_debug("Refresh status of static route {}:{} is set to false".format(val[0], val[1]))
+                else:
+                    self.db.delete(self.db.APPL_DB, sr)
+                    log_debug("Static route {}:{} deleted".format(val[0], val[1]))
+        self.start = time.time()
+        return
+
+    def run(self):
+        self.start = time.time()
+        while True:
+            self.set_timer()
+            if self.timer:
+                log_info("Static route expiry set to {}s".format(self.timer))
+                time.sleep(self.timer)
+                self.alarm()
+            else:
+                time.sleep(self.DEFAULT_SLEEP)
+                if time.time() - self.start >= self.DEFAULT_TIMER:
+                    self.alarm()