Author: Pahaz Blinov

Repo: https://github.com/pahaz/sshtunnel/

Inspired by https://github.com/jmagnusson/bgtunnel, but it doesn't work on Windows.

See also: https://github.com/paramiko/paramiko/blob/master/demos/forward.py

Requirements

• paramiko

Installation

sshtunnel is on PyPI, so simply run:

pip install sshtunnel

or :

easy_install sshtunnel

to have it installed in your environment.

For installing from source, clone the repo and run:

python setup.py install

Testing the package

In order to run the tests you first need tox and run:

python setup.py test

Usage scenarios

One of the typical scenarios where sshtunnel is helpful is depicted in the figure below. User may need to connect a port of a remote server (i.e. 8080) where only SSH port (usually port 22) is reachable. :

----------------------------------------------------------------------

                            |
-------------+              |    +----------+
    LOCAL    |              |    |  REMOTE  | :22 SSH
    CLIENT   | <== SSH ========> |  SERVER  | :8080 web service
-------------+              |    +----------+
                            |
                         FIREWALL (only port 22 is open)

----------------------------------------------------------------------

Fig1: How to connect to a service blocked by a firewall through SSH tunnel.

If allowed by the SSH server, it is also possible to reach a private server (from the perspective of REMOTE SERVER) not directly visible from the outside (LOCAL CLIENT's perspective). :

----------------------------------------------------------------------

                            |
-------------+              |    +----------+               +---------
    LOCAL    |              |    |  REMOTE  |               | PRIVATE
    CLIENT   | <== SSH ========> |  SERVER  | <== local ==> | SERVER
-------------+              |    +----------+               +---------
                            |
                         FIREWALL

----------------------------------------------------------------------

Fig2: How to connect to PRIVATE SERVER through SSH tunnel.

Usage examples

API allows either initializing the tunnel and starting it or using a with context, which will take care of starting and stopping the tunnel:

Example 1

from sshtunnel import SSHTunnelForwarder

server = SSHTunnelForwarder(
    ('pahaz.urfuclub.ru', 22),
    ssh_username="pahaz",
    ssh_password="secret",
    remote_bind_address=('127.0.0.1', 5555)
)

server.start()

print(server.local_bind_port)
# work with `SECRET SERVICE` through `server.local_bind_port`.

server.stop()

Example 2

Example of a port forwarding for the Vagrant MySQL local port:

from sshtunnel import SSHTunnelForwarder
from time import sleep

with SSHTunnelForwarder(
    ('localhost', 2222),
    ssh_username="vagrant",
    ssh_password="vagrant",
    remote_bind_address=('127.0.0.1', 3306)
) as server:

    print(server.local_bind_port)
    while True:
        # press Ctrl-C for stopping
        sleep(1)

print('FINISH!')

Or simply using the CLI:

$ python -m sshtunnel -U vagrant -P vagrant -L :3306 -R 127.0.0.1:3306 -p 2222 localhost

CLI usage

usage: sshtunnel [-h] [-U SSH_USERNAME] [-p SSH_PORT] [-P SSH_PASSWORD] -R
                 IP:PORT [IP:PORT ...] [-L [IP:PORT [IP:PORT ...]]]
                 [-k SSH_HOST_KEY] [-K KEY_FILE] [-S KEY_PASSWORD] [-t]
                 [-v] [-V] [-x IP:PORT] [-c SSH_CONFIG_FILE] [-z] [-n]
                 ssh_address

Pure python ssh tunnel utils

positional arguments:
  ssh_address           SSH server IP address (GW for ssh tunnels)
                        set with "-- ssh_address" if immediately after -R or -L

optional arguments:
  -h, --help            show this help message and exit
  -U, --username SSH_USERNAME
                        SSH server account username
  -p, --server_port SSH_PORT
                        SSH server TCP port (default: 22)
  -P, --password SSH_PASSWORD
                        SSH server account password
  -R, --remote_bind_address IP:PORT [IP:PORT ...]
                        Remote bind address sequence: ip_1:port_1 ip_2:port_2 ... ip_n:port_n
                        Equivalent to ssh -Lxxxx:IP_ADDRESS:PORT
                        If omitted, default port is 22.
                        Example: -R 10.10.10.10: 10.10.10.10:5900
  -L, --local_bind_address [IP:PORT [IP:PORT ...]]
                        Local bind address sequence: ip_1:port_1 ip_2:port_2 ... ip_n:port_n
                        Equivalent to ssh -LPORT:xxxxxxxxx:xxxx, being the local IP address optional.
                        By default it will listen in all interfaces (0.0.0.0) and choose a random port.
                        Example: -L :40000
  -k, --ssh_host_key SSH_HOST_KEY
                        Gateway's host key
  -K, --private_key_file KEY_FILE
                        RSA/DSS/ECDSA private key file
  -S, --private_key_file_password KEY_PASSWORD
                        RSA/DSS/ECDSA private key password
  -t, --threaded        Allow concurrent connections to each tunnel
  -v, --verbosity       Increase output verbosity (default: ERROR)
  -V, --version         Show version number and quit
  -x, --proxy IP:PORT   IP and port for SSH proxy to destination
  -c, --config SSH_CONFIG_FILE
                        SSH configuration file, defaults to ~/.ssh/config
  -z, --compress        Request server for compression over SSH transport
  -n, --noagent         Disable looking for keys from an SSH agent