Nagios script to check whether a salt minion is online (with timeout)

check_salt

#!/usr/bin/env python
import salt.cli.caller
import salt.config
import argparse
import sys
import signal

class TimeoutException(Exception):
    pass

def timeout(timeout_time, default):
    def timeout_function(f):
        def f2(*args):
            def timeout_handler(signum, frame):
                raise TimeoutException()

            old_handler = signal.signal(signal.SIGALRM, timeout_handler)
            signal.alarm(timeout_time) # triger alarm in timeout_time seconds
            try:
                retval = f(*args)
            except TimeoutException:
                return default
            finally:
                signal.signal(signal.SIGALRM, old_handler)
            signal.alarm(0)
            return retval
        return f2
    return timeout_function

@timeout(10, "CRITICAL: an error occurred while trying to ping the minion!\n")
def salt_ping(hostname):
    """
    Generate a dict with the required configuration
    """
    opts = salt.config.minion_config("/etc/salt/minion")
    opts['doc'] = False
    opts['grains_run'] = False
    opts['raw_out'] = False
    opts['json_out'] = True
    opts['txt_out'] = False
    opts['yaml_out'] = False
    opts['color'] = True
    opts['root_dir'] = None
    opts['fun'] = "publish.publish"
    opts['returner'] = None
    opts['arg'] = (hostname, "test.ping")

    # Run the salt command
    caller = salt.cli.caller.Caller(opts)
    result = caller.call()

    if result.get("return").get(hostname) is True:
        return "OK: minion %s is online\n" % hostname
    else:
        return "CRITICAL: minion %s is not online!\n" % hostname

if __name__ == '__main__':
    parser = argparse.ArgumentParser(description='Check if minions are online.')
    parser.add_argument('hostname', help='The name of the minion to be checked')

    args = parser.parse_args()

    sys.stdout.write(salt_ping(args.hostname))