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import sys
import socket
import getpass
import paramiko as ssh
from paramiko.resource import ResourceManager
from fabric import network
from fabric import state as s
def connect_forward(gw, host, port, user):
Create a different connect that works with a gateway. We really need to
create the socket and destroy it when the connection fails and then retry
the connect.
client = ForwardSSHClient()
while True:
# Load known host keys (e.g. ~/.ssh/known_hosts) unless user says not to.
if not s.env.disable_known_hosts:
# Unless user specified not to, accept/add new, unknown host keys
if not s.env.reject_unknown_hosts:
sock = gw.get_transport().open_channel('direct-tcpip', (host, int(port)), ('', 0))
client.connect(host, sock, int(port), user, s.env.password,
key_filename=s.env.key_filename, timeout=10)
client._sock_ = sock
return client
except (
), e:
if e.__class__ is ssh.SSHException and password:
s.env.password = network.prompt_for_password(s.env.password)
except (EOFError, TypeError):
# Print a newline (in case user was sitting at prompt)
# Handle timeouts
except socket.timeout:
network.abort('Timed out trying to connect to %s' % host)
# Handle DNS error / name lookup failure
except socket.gaierror:
network.abort('Name lookup failed for %s' % host)
# Handle generic network-related errors
# NOTE: In 2.6, socket.error subclasses IOError
except socket.error, e:
network.abort('Low level socket error connecting to host %s: %s' % (
host, e[1])
class ForwardSSHClient(ssh.SSHClient):
Override the default ssh.SSHClient to make it accept a socket as an extra argument,
instead of creating one of its own.
def connect(self, hostname, sock, port=22, username=None, password=None, pkey=None,
key_filename=None, timeout=None, allow_agent=True, look_for_keys=True):
t = self._transport = ssh.Transport(sock)
if self._log_channel is not None:
ResourceManager.register(self, t)
server_key = t.get_remote_server_key()
keytype = server_key.get_name()
our_server_key = self._system_host_keys.get(hostname, {}).get(keytype, None)
if our_server_key is None:
our_server_key = self._host_keys.get(hostname, {}).get(keytype, None)
if our_server_key is None:
# will raise exception if the key is rejected; let that fall out
self._policy.missing_host_key(self, hostname, server_key)
# if the callback returns, assume the key is ok
our_server_key = server_key
if server_key != our_server_key:
raise ssh.BadHostKeyException(hostname, server_key, our_server_key)
if username is None:
username = getpass.getuser()
if key_filename is None:
key_filenames = []
elif isinstance(key_filename, (str, unicode)):
key_filenames = [ key_filename ]
key_filenames = key_filename
self._auth(username, password, pkey, key_filenames, allow_agent, look_for_keys)
class GatewayConnectionCache(network.HostConnectionCache):
_gw = None
def __getitem__(self, key):
gw = s.env.get('gateway')
if gw is None:
return super(GatewayConnectionCache, self).__getitem__(key)
gw_user, gw_host, gw_port = network.normalize(gw)
if self._gw is None:
# Normalize given key (i.e. obtain username and port, if not given)
self._gw = network.connect(gw_user, gw_host, gw_port)
# Normalize given key (i.e. obtain username and port, if not given)
user, host, port = network.normalize(key)
# Recombine for use as a key.
real_key = network.join_host_strings(user, host, port)
# If not found, create new connection and store it
if real_key not in self:
self[real_key] = connect_forward(self._gw, host, port, user)
# Return the value either way
return dict.__getitem__(self, real_key)
_c = s.connections = GatewayConnectionCache()
from fabric import operations
operations.connections = _c
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