def startShell( self, *args, **kwargs ):
"Start a shell process for running commands"
if self.shell:
error( "%s: shell is already running\n" % self.name )
return
# mnexec: (c)lose descriptors, (d)etach from tty,
# (p)rint pid, and run in (n)amespace
# opts = '-cd' if mnopts is None else mnopts
# if self.inNamespace:
# opts += 'n'
# bash -i: force interactive
# -s: pass $* to shell, and make process easy to find in ps
# prompt is set to sentinel chr( 127 )
cmd = [ 'docker', 'exec', '-it', '%s.%s' % ( self.dnameprefix, self.name ), 'env', 'PS1=' + chr( 127 ),
'bash', '--norc', '-is', 'mininet:' + self.name ]
# Spawn a shell subprocess in a pseudo-tty, to disable buffering
# in the subprocess and insulate it from signals (e.g. SIGINT)
# received by the parent
master, slave = pty.openpty()
self.shell = self._popen( cmd, stdin=slave, stdout=slave, stderr=slave,
close_fds=False )
self.stdin = os.fdopen( master, 'rw' )
self.stdout = self.stdin
self.pid = self._get_pid()
self.pollOut = select.poll()
self.pollOut.register( self.stdout )
# Maintain mapping between file descriptors and nodes
# This is useful for monitoring multiple nodes
# using select.poll()
self.outToNode[ self.stdout.fileno() ] = self
self.inToNode[ self.stdin.fileno() ] = self
self.execed = False
self.lastCmd = None
self.lastPid = None
self.readbuf = ''
# Wait for prompt
while True:
data = self.read( 1024 )
if data[ -1 ] == chr( 127 ):
break
self.pollOut.poll()
self.waiting = False
# +m: disable job control notification
self.cmd( 'unset HISTFILE; stty -echo; set +m' )
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