Restart UPS Agent every 60 minutes (#592)

* exit ups agent after 60 min

This is a temporary workaround to a memory leak in this agent.

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* no crash in test mode

* address comments

* fix log

* update docs

* fix condition

---------

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

docs/agents/ups.rst

@@ -31,10 +31,13 @@ using all of the available arguments::
        'arguments': [['--address', '10.10.10.50'],
                      ['--port', 161],
                      ['--mode', 'acq'],
-                     ['--snmp-version', 1]]},
+                     ['--snmp-version', 1],
+                     ['--restart-time', 60]]},
 
 .. note::
     The ``--address`` argument should be the address of the UPS on the network.
+    The ``--restart-time`` argument should be set to number of minutes before
+    exiting the agent. Setting to 0 (default) will not exit the agent.
 
 Docker Compose
 ``````````````
@@ -57,6 +60,8 @@ example docker-compose service configuration is shown here::
 
 The ``LOGLEVEL`` environment variable can be used to set the log level for
 debugging. The default level is "info".
+If not using HostManager, we must set ``restart: unless-stopped``
+to automatically restart the docker container.
 
 Description
 -----------

socs/agents/ups/agent.py

@@ -1,5 +1,6 @@
 import argparse
 import os
+import signal
 import time
 
 import txaio
@@ -172,7 +173,7 @@ class UPSAgent:
         txaio logger object, created by the OCSAgent
     """
 
-    def __init__(self, agent, address, port=161, version=1):
+    def __init__(self, agent, address, port=161, version=1, restart_time=0):
         self.agent = agent
         self.is_streaming = False
         self.log = self.agent.log
@@ -182,6 +183,7 @@ def __init__(self, agent, address, port=161, version=1):
         self.version = version
         self.snmp = SNMPTwister(address, port)
         self.connected = True
+        self.restart = restart_time
 
         self.lastGet = 0
 
@@ -308,7 +310,10 @@ def acq(self, session, params=None):
 
         session.set_status('running')
         self.is_streaming = True
+        timeout = time.time() + 60 * self.restart  # exit loop after self.restart minutes
         while self.is_streaming:
+            if ((self.restart != 0) and (time.time() > timeout)):
+                break
             yield dsleep(1)
             if not self.connected:
                 self.log.error('No SNMP response. Check your connection.')
@@ -432,6 +437,12 @@ def acq(self, session, params=None):
             if params['test_mode']:
                 break
 
+        # Exit agent to release memory
+        # Add "restart: unless-stopped" to docker-compose to automatically restart container
+        if ((not params['test_mode']) and (timeout != 0) and (self.is_streaming)):
+            self.log.info(f"{self.restart} minutes have elasped. Exiting agent.")
+            os.kill(os.getppid(), signal.SIGTERM)
+
         return True, "Finished Recording"
 
     def _stop_acq(self, session, params=None):
@@ -461,6 +472,8 @@ def add_agent_args(parser=None):
     pgroup.add_argument("--snmp-version", default='1', choices=['1', '2', '3'],
                         help="SNMP version for communication. Must match "
                              + "configuration on the UPS.")
+    pgroup.add_argument("--restart-time", default=0,
+                        help="Number of minutes before restarting agent.")
     pgroup.add_argument("--mode", choices=['acq', 'test'])
 
     return parser
@@ -484,7 +497,8 @@ def main(args=None):
     p = UPSAgent(agent,
                  address=args.address,
                  port=int(args.port),
-                 version=int(args.snmp_version))
+                 version=int(args.snmp_version),
+                 restart_time=int(args.restart_time))
 
     agent.register_process("acq",
                            p.acq,