def __assert_server_reachable(self):
if not is_port_bound(self.host, self.port):
if self.remote and not self.remote.is_port_bound(self._host, self._port):
self.disconnect()
raise DuctServerUnreachable(
"Remote '{}' cannot connect to '{}:{}'. Please check your settings before trying again.".format(
self.remote.name, self._host, self._port))
elif not self.remote:
self.disconnect()
raise DuctServerUnreachable(
"Cannot connect to '{}:{}' on your current connection. Please check your connection before trying again.".format(
self.host, self.port))
def port_forward(self, remote_host, remote_port=None, local_port=None):
'''
Establishes a local port forwarding from local port `local` to remote
port `remote`. If `local` is `None`, automatically find an available local
port, and forward it. This method returns the used local port.
If the remote port is already forwarded, a new connection is not created.
'''
# Hostname and port extraction
remote_host, remote_port, local_port = self.__extract_host_and_ports(remote_host, remote_port, local_port)
assert remote_host is not None, "Remote host must be specified."
assert remote_port is not None, "Remote port must be specified."
# Actual port forwarding
registered_port = self.__port_forwarding_register.lookup_port(remote_host, remote_port)
if registered_port is not None:
if local_port is not None and registered_port != local_port:
self.port_forward_stop(registered_port)
else:
return registered_port
if local_port is None:
local_port = get_free_local_port()
else:
assert is_local_port_free(local_port), "Specified local port is in use, and cannot be used."
if not self.is_port_bound(remote_host, remote_port):
raise DuctServerUnreachable("Server specified for port forwarding ({}:{}) in unreachable.".format(remote_host, remote_port))
connection = self.connect()._port_forward_start(local_port, remote_host, remote_port)
self.__port_forwarding_register.register(remote_host, remote_port, local_port, connection)
return local_port
def __assert_server_reachable(self):
if self.host is not None or self.port is not None:
if self.host is None:
raise ValueError("Port specified but no host provided.")
if self.port is None:
raise ValueError("Host specified but no port specified.")
else:
return
if not is_port_bound(self.host, self.port):
if self.remote and not self.remote.is_port_bound(self._host, self._port):
self.disconnect()
raise DuctServerUnreachable(
"Remote '{}' cannot connect to '{}:{}'. Please check your settings before trying again.".format(
self.remote.name, self._host, self._port))
elif not self.remote:
self.disconnect()
raise DuctServerUnreachable(
"Cannot connect to '{}:{}' on your current connection. Please check your connection before trying again.".format(
self.host, self.port))
def port_forward(self, remote_host, remote_port=None, local_port=None):
"""
Initiate a port forward connection.
This method establishes a local port forwarding from a local port `local`
to remote port `remote`. If `local` is `None`, an available local port is
automatically chosen. If the remote port is already forwarded, a new
connection is not established.
Args:
remote_host (str): The hostname of the remote host in form:
'hostname(:port)'.
remote_port (int, None): The remote port of the service.
local_port (int, None): The port to use locally (automatically
determined if not specified).
Returns:
int: The local port which is port forwarded to the remote service.
"""
# Hostname and port extraction
remote_host, remote_port, local_port = self._extract_host_and_ports(
remote_host, remote_port, local_port)
assert remote_host is not None, "Remote host must be specified."
assert remote_port is not None, "Remote port must be specified."
# Actual port forwarding
registered_port = self.__port_forwarding_register.lookup_port(
remote_host, remote_port)
if registered_port is not None:
if local_port is not None and registered_port != local_port:
self.port_forward_stop(registered_port)
else:
return registered_port
if local_port is None:
local_port = get_free_local_port()
else:
assert is_local_port_free(
local_port
), "Specified local port is in use, and cannot be used."
if not self.is_port_bound(remote_host, remote_port):
raise DuctServerUnreachable(
"Server specified for port forwarding ({}:{}) is unreachable via '{}' ({})."
.format(remote_host, remote_port, self.name,
self.__class__.__name__))
connection = self._port_forward_start(local_port, remote_host,
remote_port)
self.__port_forwarding_register.register(remote_host, remote_port,
local_port, connection)
return local_port