sonic-buildimage/files/image_config/monit/process_checker
bingwang-ms 7a015eacc1 Fix 'NoSuchProcess' exception in process_checker (#5716)
The psutil library used in process_checker create a cache for each
process when calling process_iter. So, there is some possibility that
one process exists when calling process_iter, but not exists when
calling cmdline, which will raise a NoSuchProcess exception. This commit
fix the issue.

Signed-off-by: bingwang <bingwang@microsoft.com>
2020-10-30 08:56:10 -07:00

61 lines
2.5 KiB
Python
Executable File

#!/usr/bin/python
import argparse
import sys
import syslog
import psutil
import swsssdk
def check_process_existence(container_name, process_cmdline):
"""
@summary: Check whether the process in the specified container is running or not and
an alerting message will written into syslog if it failed to run.
"""
config_db = swsssdk.ConfigDBConnector()
config_db.connect()
feature_table = config_db.get_table("FEATURE")
if container_name in feature_table.keys():
# We look into the 'FEATURE' table to verify whether the container is disabled or not.
# If the container is diabled, we exit.
if ("state" in feature_table[container_name].keys()
and feature_table[container_name]["state"] == "disabled"):
sys.exit(0)
else:
# We leveraged the psutil library to help us check whether the process is running or not.
# If the process entity is found in process tree and it is also in the 'running' or 'sleeping'
# state, then it will be marked as 'running'.
is_running = False
for process in psutil.process_iter(["cmdline", "status"]):
try:
if ((' '.join(process.cmdline())).startswith(process_cmdline) and process.status() in ["running", "sleeping"]):
is_running = True
break
except psutil.NoSuchProcess:
pass
if not is_running:
# If this script is run by Monit, then the following output will be appended to
# Monit's syslog message.
print("'{}' is not running.".format(process_cmdline))
sys.exit(1)
else:
syslog.syslog(syslog.LOG_ERR, "container '{}' is not included in SONiC image or the given container name is invalid!"
.format(container_name))
def main():
parser = argparse.ArgumentParser(description="Check whether the process in the specified \
container is running and an alerting message will be written into syslog if it \
failed to run.", usage="/usr/bin/process_checker <container_name> <process_cmdline>")
parser.add_argument("container_name", help="container name")
parser.add_argument("process_cmdline", nargs=argparse.REMAINDER, help="process command line")
args = parser.parse_args()
check_process_existence(args.container_name, ' '.join(args.process_cmdline))
if __name__ == '__main__':
main()