do even more logging
[zanchey/dispense2.git] / sql-edition / servers / VendServer.py
index 974e0b4..a09ac2a 100755 (executable)
@@ -5,7 +5,8 @@ USE_DB = 0
 
 import ConfigParser
 import sys, os, string, re, pwd, signal
-from traceback import print_tb
+import logging, logging.handlers
+from traceback import format_tb
 if USE_DB: import pg
 from time import time, sleep
 from popen2 import popen2
@@ -24,6 +25,8 @@ DOOR = 1
 SWITCH = 2
 KEY = 3
 
+class DispenseDatabaseException(Exception): pass
+
 class DispenseDatabase:
        def __init__(self, vending_machine, host, name, user, password):
                self.vending_machine = vending_machine
@@ -31,16 +34,15 @@ class DispenseDatabase:
                self.db.query('LISTEN vend_requests')
 
        def process_requests(self):
-               print 'processing'
+               logging.debug('database processing')
                query = 'SELECT request_id, request_slot FROM vend_requests WHERE request_handled = false'
                try:
                        outstanding = self.db.query(query).getresult()
                except (pg.error,), db_err:
-                       sys.stderr.write('Failed to query database: %s\n'%(db_err.strip()))
-                       return
+                       raise DispenseDatabaseException('Failed to query database: %s\n'%(db_err.strip()))
                for (id, slot) in outstanding:
                        (worked, code, string) = self.vending_machine.vend(slot)
-                       print (worked, code, string)
+                       logging.debug (str((worked, code, string)))
                        if worked:
                                query = 'SELECT vend_success(%s)'%id
                                self.db.query(query).getresult()
@@ -114,7 +116,7 @@ def verify_user_pin(uid, pin):
                return None
 
 def door_open_mode(v):
-       print "Entering open door mode"
+       logging.warning("Entering open door mode")
        v.display("-FEED  ME-")
        while True:
                e = v.next_event()
@@ -122,6 +124,7 @@ def door_open_mode(v):
                (event, params) = e
                if event == DOOR:
                        if params == 1: # door closed
+                               logging.warning('Leaving open door mode')
                                v.display("-YUM YUM!-")
                                sleep(1)
                                return
@@ -201,7 +204,7 @@ class MessageKeeper:
 
 def run_forever(rfh, wfh, options, cf):
        v = VendingMachine(rfh, wfh)
-       print 'PING is', v.ping()
+       logging.debug('PING is', v.ping())
 
        if USE_DB: db = DispenseDatabase(v, cf.DBServer, cf.DBName, cf.DBUser, cf.DBPassword)
        cur_user = ''
@@ -218,7 +221,11 @@ def run_forever(rfh, wfh, options, cf):
        last_timeout_refresh = None
 
        while True:
-               if USE_DB: db.handle_events()
+               if USE_DB:
+                       try:
+                               db.handle_events()
+                       except DispenseDatabaseException, e:
+                               logging.error('Database error: '+str(e))
 
                if time_to_autologout != None:
                        time_left = time_to_autologout - time()
@@ -253,7 +260,7 @@ def run_forever(rfh, wfh, options, cf):
                                continue
                time_to_idle = None
                (event, params) = e
-               print e
+               logging.debug('Got event: ' + repr(e))
                if event == DOOR:
                        if params == 0:
                                door_open_mode(v);
@@ -388,12 +395,15 @@ def parse_args():
 
        op = OptionParser(usage="%prog [OPTION]...")
        op.add_option('-f', '--config-file', default='/etc/dispense/servers.conf', metavar='FILE', dest='config_file', help='use the specified config file instead of /etc/dispense/servers.conf')
-       op.add_option('-v', '--virtualvend', action='store_false', default=True, dest='use_lat', help='use the virtual vending server instead of LAT')
+       op.add_option('--virtualvend', action='store_false', default=True, dest='use_lat', help='use the virtual vending server instead of LAT')
        op.add_option('-n', '--hostname', dest='host', default='localhost', help='the hostname to connect to for virtual vending machine mode (default: localhost)')
        op.add_option('-p', '--port', dest='port', default=5150, type='int', help='the port number to connect to (default: 5150)')
        op.add_option('-l', '--log-file', metavar='FILE', dest='log_file', default='', help='log output to the specified file')
        op.add_option('-s', '--syslog', dest='syslog', action='store_true', default=False, help='log output to syslog')
        op.add_option('-d', '--daemon', dest='daemon', action='store_true', default=False, help='run as a daemon')
+       op.add_option('-v', '--verbose', dest='verbose', action='store_true', default=False, help='spit out lots of debug output')
+       op.add_option('-q', '--quiet', dest='quiet', action='store_true', default=False, help='only report errors')
+       op.add_option('--pid-file', dest='pid_file', metavar='FILE', default='', help='store daemon\'s pid in the given file')
        options, args = op.parse_args()
 
        if len(args) != 0:
@@ -427,56 +437,121 @@ class VendConfigFile:
                                self.__dict__[option] = value
                
                except ConfigParser.Error, e:
-                       print "Error reading config file "+config_file+": " + str(e)
+                       logging.critical("Error reading config file "+config_file+": " + str(e))
+                       logging.critical("Bailing out")
                        sys.exit(1)
 
-def do_vend_server():
+def create_pid_file(name):
+       try:
+               pid_file = file(name, 'w')
+               pid_file.write('%d\n'%os.getpid())
+               pid_file.close()
+       except IOError, e:
+               logging.warning('unable to write to pid file '+name+': '+str(e))
+
+def set_stuff_up():
+       def do_nothing(signum, stack):
+               signal.signal(signum, do_nothing)
+       def stop_server(signum, stack): raise KeyboardInterrupt
+       signal.signal(signal.SIGHUP, do_nothing)
+       signal.signal(signal.SIGTERM, stop_server)
+       signal.signal(signal.SIGINT, stop_server)
+
        options = parse_args()
+       set_up_logging(options)
        config_opts = VendConfigFile(options.config_file, config_options)
+       if options.daemon: become_daemon()
+       if options.pid_file != '': create_pid_file(options.pid_file)
+
+       return options, config_opts
+
+def clean_up_nicely(options, config_opts):
+       if options.pid_file != '':
+               try:
+                       os.unlink(options.pid_file)
+                       logging.debug('Removed pid file '+options.pid_file)
+               except OSError: pass  # if we can't delete it, meh
 
+def set_up_logging(options):
+       logger = logging.getLogger()
+       
+       stderr_logger = logging.StreamHandler(sys.stderr)
+       stderr_logger.setFormatter(logging.Formatter('%(levelname)s: %(message)s'))
+       logger.addHandler(stderr_logger)
+       
+       if options.log_file != '':
+               try:
+                       file_logger = logging.FileHandler(options.log_file)
+                       file_logger.setFormatter(logging.Formatter('%(asctime)s %(levelname)s: %(message)s'))
+                       logger.addHandler(file_logger)
+               except IOError, e:
+                       logger.warning('unable to write to log file '+options.log_file+': '+str(e))
+
+       if options.syslog:
+               sys_logger = logging.handlers.SysLogHandler('/dev/log', 'daemon')
+               sys_logger.setFormatter(logging.Formatter('vendserver[%d]'%(os.getpid()) + ' %(levelname)s: %(message)s'))
+               logger.addHandler(sys_logger)
+
+       if options.quiet:
+               logger.setLevel(logging.WARNING)
+       elif options.verbose:
+               logger.setLevel(logging.DEBUG)
+       else:
+               logger.setLevel(logging.INFO)
+
+def become_daemon():
+       dev_null = file('/dev/null')
+       fd = dev_null.fileno()
+       os.dup2(fd, 0)
+       os.dup2(fd, 1)
+       os.dup2(fd, 2)
+       if os.fork() != 0:
+               sys.exit(0)
+
+def do_vend_server(options, config_opts):
        while True:
                try:
                        rfh, wfh = connect_to_vend(options, config_opts)
                except (LATClientException, socket.error), e:
                        (exc_type, exc_value, exc_traceback) = sys.exc_info()
                        del exc_traceback
-                       print
-                       print "Connection error: "+str(exc_type)+" "+str(e)
-                       print "Trying again in 5 seconds."
+                       logging.error("Connection error: "+str(exc_type)+" "+str(e))
+                       logging.info("Trying again in 5 seconds.")
                        sleep(5)
                        continue
+               
                try:
                        run_forever(rfh, wfh, options, config_opts)
                except VendingException:
-                       print
-                       print "Connection died, trying again..."
+                       logging.error("Connection died, trying again...")
+                       logging.info("Trying again in 5 seconds.")
+                       sleep(5)
 
 if __name__ == '__main__':
-       def do_nothing(signum, stack): pass
-       def stop_server(signum, stack): raise KeyboardInterrupt
-       signal.signal(signal.SIGHUP, do_nothing)
-       signal.signal(signal.SIGTERM, stop_server)
-       signal.signal(signal.SIGINT, stop_server)
+       options, config_opts = set_stuff_up()
        while True:
                try:
-                       do_vend_server()
+                       logging.info('Starting Vend Server')
+                       do_vend_server(options, config_opts)
+                       logging.warning('Vend Server finished unexpectedly, restarting')
                except KeyboardInterrupt:
-                       print "Killed by signal."
+                       logging.info("Killed by signal, cleaning up")
+                       clean_up_nicely(options, config_opts)
+                       logging.info("Vend Server stopped")
                        break
-               except SystemExit, e:
-                       raise e
                except:
                        (exc_type, exc_value, exc_traceback) = sys.exc_info()
-                       print
-                       print "Uh-oh, unhandled " + str(exc_type) + " exception"
-                       print "Message: ", str(exc_value)
-                       print
-                       print_tb(exc_traceback)
+                       tb = format_tb(exc_traceback, 20)
                        del exc_traceback
-                       print
-                       print "This message should be considered a bug in the Vend Server."
-                       print "Please report this to someone who can fix it."
+                       
+                       logging.critical("Uh-oh, unhandled " + str(exc_type) + " exception")
+                       logging.critical("Message: " + str(exc_value))
+                       logging.critical("Traceback:")
+                       for event in tb:
+                               for line in event.split('\n'):
+                                       logging.critical('    '+line)
+                       logging.critical("This message should be considered a bug in the Vend Server.")
+                       logging.critical("Please report this to someone who can fix it.")
                        sleep(10)
-                       print
-                       print "Trying again anyway (might not help, but hey...)"
+                       logging.warning("Trying again anyway (might not help, but hey...)")
 

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