Oscam helper script to restart reader on error

etc_systemd_system_oscam.service.d_override.conf

[Unit]
Description=A helper service to execute and monitor oscam written in Python

[Service]
Environment=PYTHONUNBUFFERED=true CONFIGPATH=/var/lib/oscam
ExecStart=
ExecStart=/usr/bin/python3 /usr/local/bin/oscam.py
SyslogIdentifier=oscam-py
Type=simple
TimeoutStopSec=1
Restart=on-failure
RestartSec=3
StartLimitInterval=0

usr_local_bin_oscam.py

#!/usr/bin/python3

# oscam.conf:
# logfile = syslog;stdout
# reload_readers = 1

from subprocess import Popen, PIPE
from signal import signal, Signals
from os import getenv
from sys import exit

restartreaders = ["THIS WAS A FAILED START ATTEMPT", 
                  "Error activating card",
                  "card system not supported",
                  "card initializing error",
                  "Cannot open device",
                  "SR: USB bulk read failed with error",
                  "Error activating card",
                  "rejected group (0 ms) (no MATCHED reader)",
                 ]
restartoscam   = ["(login failure)", 
                  "AU disabled for user",
                 ]
restartscript  = [ 
                 ]
stoposcam      = [ 
                 ]

def contain(string_, substrings):
    return any(s in string_ for s in substrings)

def handler(signum, frame):
   global restart ; restart =  False
   print("Received ", Signals(signum).name, ", should not restart oscam and script.")

restart = True
rc = 0
signal(Signals.SIGINT, handler)

while restart:
   print("Starting oscam")
   proc = Popen(["oscam", "-c", getenv('CONFIGPATH'), "-r", "0"],
         stdout=PIPE, bufsize=1, universal_newlines=True)
   for line in iter(proc.stdout.readline, ''):
#      print("OSCAM:" + line.rstrip())
      if contain(line, restartreaders):
         print("MATCHED: ", line , "Sending SIGHUP, Oscam should restart the reader", sep='')
         proc.send_signal(Signals.SIGHUP)
      elif contain(line, restartoscam):
         print("MATCHED: ", line , "Sending SIGTERM, Script should restart oscam", sep='')
         proc.send_signal(Signals.SIGTERM)
      elif contain(line, restartscript):
         restart = False
         rc = 1
         print("MATCHED: ", line , "Sending SIGINT, Service should restart script", sep='')
         proc.terminate()
      elif contain(line, stoposcam):
         restart = False
         print("MATCHED: ", line , "Sending SIGINT, Service should stop", sep='')
         proc.terminate()
            
   proc.wait(2)
   if proc.returncode != 99:
      print("Oscam not requesting to restart (", proc.returncode, ")", sep='' )
      restart = False
   else:
      print("Oscam requesting to restart (", proc.returncode, ")", sep='' )

   proc.kill()

print("Finished Oscam and script, return", rc, "to systemd")
exit(rc)