def connectApp(ns, name):
"""
Connects to a remote application.
:param Pyro4.naming.Nameserver ns: Instance of a nameServer
:param str name: Name of the application to be connected to
:return: Application
:rtype: Instance of an application
:raises Exception: When cannot find registered server or Cannot connect to application
"""
try:
uri = ns.lookup(name)
log.debug("Found URI %s from a nameServer %s" % (uri, ns) )
app2 = Pyro4.Proxy(uri)
except Exception as e:
log.error("Cannot find registered server %s on %s" % (name, ns) )
raise
try:
sig = app2.getApplicationSignature()
log.debug("Connected to " + sig + " with the name " + name)
except Exception as e:
log.exception("Cannot connect to application " + name + ". Is the server running?")
raise
return app2
def sshTunnel(remoteHost, userName, localPort, remotePort, sshClient='ssh', options='', sshHost='', Reverse=False):
"""
Automatic creation of ssh tunnel, using putty.exe for Windows and ssh for Linux
:param str remoteHost: IP of remote host
:param str userName: User name, if empty, current user name is used
:param int localPort: Local port
:param int remotePort: Remote port
:param str sshClient: Path to executable ssh client (on Windows use double backslashes 'C:\\Program Files\\Putty\putty.exe')
:param str options: Arguments to ssh clinent, e.g. the location of private ssh keys
:param str sshHost: Computer used for tunelling, optional. If empty, equals to remoteHost
:param bool Reverse: True if reverse tunnel to be created (default is False)
:return: Instance of subprocess.Popen running the tunneling command
:rtype: subprocess.Popen
:raises Exception: if creation of a tunnel failed
"""
if sshHost =='':
sshHost = remoteHost
if userName =='':
userName = os.getenv('USER')
direction = 'L'
if Reverse == True:
direction = 'R'
#use direct system command. Paramiko or sshtunnel do not work.
#put ssh public key on a server - interaction with a keyboard for password will not work here (password goes through TTY, not stdin)
if sshClient=='ssh':
cmd = 'ssh -%s %d:%s:%d %s@%s -N %s' % (direction, localPort, remoteHost, remotePort, userName, sshHost, options)
log.debug("Creating ssh tunnel via command: " + cmd)
elif sshClient=='autossh':
cmd = 'autossh -%s %d:%s:%d %s@%s -N %s' % (direction, localPort, remoteHost, remotePort, userName, sshHost, options)
log.debug("Creating autossh tunnel via command: " + cmd)
elif 'putty' in sshClient.lower():
#need to create a public key *.ppk using puttygen. It can be created by importing Linux private key. The path to that key is given as -i option
cmd = '%s -%s %d:%s:%d %s@%s -N %s' % (sshClient, direction, localPort, remoteHost, remotePort, userName, sshHost, options)
log.debug("Creating ssh tunnel via command: " + cmd)
elif sshClient=='manual':
#You need ssh server running, e.g. UNIX-sshd or WIN-freesshd
cmd1 = 'ssh -%s %d:%s:%d %s@%s -N %s' % (direction, localPort, remoteHost, remotePort, userName, sshHost, options)
cmd2 = 'putty.exe -%s %d:%s:%d %s@%s -N %s' % (direction, localPort, remoteHost, remotePort, userName, sshHost, options)
log.info("If ssh tunnel does not exist, do it manually using a command e.g. " + cmd1 + " , or " + cmd2)
return 'manual'
else:
log.error("Unknown ssh client, exiting")
exit(0)
try:
tunnel = subprocess.Popen(cmd.split())
except Exception:
log.exception("Creation of a tunnel failed. Can not execute the command: %s " % cmd)
raise
time.sleep(1.0)
return tunnel
