Source Code for Module buildslave.scripts.logwatcher

  1   
  2  import os 
  3  from twisted.python.failure import Failure 
  4  from twisted.internet import defer, reactor, protocol, error 
  5  from twisted.protocols.basic import LineOnlyReceiver 
  6   
  7 -class FakeTransport: 
  8      disconnecting = False 
  9   
 10 -class BuildmasterTimeoutError(Exception): 
 11      pass 
 12 -class BuildslaveTimeoutError(Exception): 
 13      pass 
 14 -class ReconfigError(Exception): 
 15      pass 
 16 -class BuildSlaveDetectedError(Exception): 
 17      pass 
 18   
 19 -class TailProcess(protocol.ProcessProtocol): 
 20 -    def outReceived(self, data): 
 21          self.lw.dataReceived(data) 
 22 -    def errReceived(self, data): 
 23          print "ERR: '%s'" % (data,) 
 24   
 25   
 26 -class LogWatcher(LineOnlyReceiver): 
 27      POLL_INTERVAL = 0.1 
 28      TIMEOUT_DELAY = 10.0 
 29      delimiter = os.linesep 
 30   
 31 -    def __init__(self, logfile): 
 32          self.logfile = logfile 
 33          self.in_reconfig = False 
 34          self.transport = FakeTransport() 
 35          self.pp = TailProcess() 
 36          self.pp.lw = self 
 37          self.processtype = "buildmaster" 
 38          self.timer = None 
 39   
 40 -    def start(self): 
 41          # If the log file doesn't exist, create it now. 
 42          if not os.path.exists(self.logfile): 
 43              open(self.logfile, 'a').close() 
 44   
 45          # return a Deferred that fires when the reconfig process has 
 46          # finished. It errbacks with TimeoutError if the finish line has not 
 47          # been seen within 10 seconds, and with ReconfigError if the error 
 48          # line was seen. If the logfile could not be opened, it errbacks with 
 49          # an IOError. 
 50          self.p = reactor.spawnProcess(self.pp, "/usr/bin/tail", 
 51                                        ("tail", "-f", "-n", "0", self.logfile), 
 52                                        env=os.environ, 
 53                                        ) 
 54          self.running = True 
 55          d = defer.maybeDeferred(self._start) 
 56          return d 
 57   
 58 -    def _start(self): 
 59          self.d = defer.Deferred() 
 60          self.timer = reactor.callLater(self.TIMEOUT_DELAY, self.timeout) 
 61          return self.d 
 62   
 63 -    def timeout(self): 
 64          self.timer = None 
 65          if self.processtype == "buildmaster": 
 66              e = BuildmasterTimeoutError() 
 67          else: 
 68              e = BuildslaveTimeoutError() 
 69          self.finished(Failure(e)) 
 70   
 71 -    def finished(self, results): 
 72          try: 
 73              self.p.signalProcess("KILL") 
 74          except error.ProcessExitedAlready: 
 75              pass 
 76          if self.timer: 
 77              self.timer.cancel() 
 78              self.timer = None 
 79          self.running = False 
 80          self.in_reconfig = False 
 81          self.d.callback(results) 
 82   
 83 -    def lineReceived(self, line): 
 84          if not self.running: 
 85              return 
 86          if "Log opened." in line: 
 87              self.in_reconfig = True 
 88          if "loading configuration from" in line: 
 89              self.in_reconfig = True 
 90          if "Creating BuildSlave" in line: 
 91              self.processtype = "buildslave" 
 92   
 93          if self.in_reconfig: 
 94              print line 
 95   
 96          if "message from master: attached" in line: 
 97              return self.finished("buildslave") 
 98          if "I will keep using the previous config file" in line: 
 99              return self.finished(Failure(ReconfigError())) 
100          if "configuration update complete" in line: 
101              return self.finished("buildmaster") 
102