usyslog.py

"""
This syslog client can send UDP packets to a remote syslog server.

For more information, see RFC 3164.
"""
import usocket
import time

# Facility constants
F_KERN = const(0)
F_USER = const(1)
F_MAIL = const(2)
F_DAEMON = const(3)
F_AUTH = const(4)
F_SYSLOG = const(5)
F_LPR = const(6)
F_NEWS = const(7)
F_UUCP = const(8)
F_CRON = const(9)
F_AUTHPRIV = const(10)
F_FTP = const(11)
F_NTP = const(12)
F_AUDIT = const(13)
F_ALERT = const(14)
F_CLOCK = const(15)
F_LOCAL0 = const(16)
F_LOCAL1 = const(17)
F_LOCAL2 = const(18)
F_LOCAL3 = const(19)
F_LOCAL4 = const(20)
F_LOCAL5 = const(21)
F_LOCAL6 = const(22)
F_LOCAL7 = const(23)

# Severity constants (Names reasonably shortened)
S_EMERG = const(0)
S_ALERT = const(1)
S_CRIT = const(2)
S_ERR = const(3)
S_WARN = const(4)
S_NOTICE = const(5)
S_INFO = const(6)
S_DEBUG = const(7)

WeekDay = ['Mon', 'Tue', 'Wed', 'Thu', 'Fri', 'Sat', 'Sun']


class SyslogClient:
    def __init__(self, facility=F_USER):
        self._facility = facility

    def log(self, severity, msg):
        pass

    def alert(self, msg):
        self.log(S_ALERT, msg)

    def critical(self, msg):
        self.log(S_CRIT, msg)

    def error(self, msg):
        self.log(S_ERR, msg)

    def debug(self, msg):
        self.log(S_DEBUG, msg)

    def info(self, msg):
        self.log(S_INFO, msg)

    def notice(self, msg):
        self.log(S_NOTICE, msg)

    def warning(self, msg):
        self.log(S_WARN, msg)


class UDPClient(SyslogClient):
    def __init__(
        self, ip='127.0.0.1', my_ip='127.0.0.1', port=514, facility=F_USER):
        self._addr = usocket.getaddrinfo(ip, port)[0][4]
        self._sock = usocket.socket(usocket.AF_INET, usocket.SOCK_DGRAM)
        self._my_ip = my_ip
        super().__init__(facility)

    def log(self, severity, msg):
        year, _ , mday, hour, minute, second, weekday = list(time.localtime())[0:7]
        time_string = '%s %2s %s:%s:%s' % (
            WeekDay[weekday], mday, hour, minute, second)
        data = "<%d>%s %s %s" % (
            severity + (self._facility << 3),
            time_string,
            self._my_ip,
            msg)
        self._sock.sendto(data.encode(), self._addr)
        
    def close(self):
        self._sock.close()