sshcontroller 1.5

A package to easily run SSH commands

python-sshcontroller

This small package implements a simple interface to communicate and exchange data with remote hosts via SSH. It is essentially a wrapper around the extensive SSH library paramiko.

Installation

Run:

pip3 install --user sshcontroller

Note that the package has been exclusively tested on Python 3.6+.

Usage

All code snippets can also be found at demo.py.

1. Create a new SSH controller from a SSH key

import sshcontroller

HOST_IP = "93.184.216.34"  # an IPv4 or IPv6 address
KEY_PWD = "password"

ssh_controller = sshcontroller.SSHController(
    host=HOST_IP,
    user="olivier",
    key_path="~/.ssh/id_rsa",  # if omitted, look for keys in SSH agent and in ~/.ssh/
    key_password=KEY_PWD,      # optional
    key_type="rsa",            # rsa (default), dsa, ecdsa or ed25519
    port=22,                   # 22 is the default
)

2. Connect to remote host

ssh_controller.connect()

3. Run a command

exit_code, output = ssh_controller.run(
    command="echo 'Hello world!' > /tmp/hello.txt",
    display=True,          # display output, disabled by default
    capture=True,          # save output, disabled by default
    shell=True,            # request a shell to run the command, enabled by default
    combine_stderr=False,  # combine stderr into stdout when shell=False, disabled by default
    timeout=10,            # command timeout in seconds, None (wait indefinitely) by default
)
print(f"exit code: {exit_code}, output: {output}")

4. Transfer data with SFTP

All functions from paramiko's SFTPClient are available through the SSHController object. Check paramiko's documentation for a complete list.

In addition, the package implements additional methods:

• exists(path): check that a file or a directory exists on the remote host
• list_dirs(path): return the list of directories present in path
• list_files(path): return the list of files present in path

print(f"hello.txt exists: {ssh_controller.exists('/tmp/hello.txt')}")
print(f"bonjour.txt exists: {ssh_controller.exists('/tmp/bonjour.txt')}")

ssh_controller.get("/tmp/hello.txt", "/tmp/bonjour.txt")

with open("/tmp/bonjour.txt", 'r') as bonjour:
    for line in bonjour:
        print(line, end='')

5. Disconnect

ssh_controller.disconnect()

6. Use a SSH password instead of a key

import sshcontroller

HOST_IP = "93.184.216.34"  # an IPv4 or IPv6 address
SSH_PWD = "password"

ssh_controller = sshcontroller.SSHController(
    host=HOST_IP,
    user="olivier",
    ssh_password=SSH_PWD
)
ssh_controller.connect()

7. Run a command until an event is set

If the argument stop_event (a threading.Event object) is set when calling run(), the controller ignores timeout and stops when the given event is triggered instead. This is especially useful when using threads.

The example below starts two threads with an event attached to each one: one is pinging localhost, the other sleeps for 10s. When the sleeping thread has finished, events are triggered to also stop the pinging thread.

import logging
import queue
import sshcontroller
import threading
import time

# ... set up ssh_controller here ...

output = queue.Queue()  # a queue to store the ping command output
stop_event_sleep = threading.Event()
stop_event_ping = threading.Event()

kwargs_sleep = {
    "command": "echo 'thread sleep: sleeping for 10s' && sleep 10s",
    "display": True,
    "stop_event": stop_event_sleep,
}
kwargs_ping = {
    "command": "echo 'thread ping: starting ping' && ping localhost",
    "display": True,
    "capture": True,
    "stop_event": stop_event_ping,
}

# call run() and store the command output in the queue
def wrapper(kwargs):
    return output.put(ssh_controller.run(**kwargs))

thread_sleep = threading.Thread(
    target=ssh_controller.run, name="thread_sleep", kwargs=kwargs_sleep)
thread_ping = threading.Thread(
    target=wrapper, name="thread_ping", args=(kwargs_ping, ))

thread_ping.start()
thread_sleep.start()

try:
    thread_sleep.join()
except KeyboardInterrupt:
    logging.info("KeyboardInterrupt")
finally:
    logging.info("Stopping threads")
    stop_event_sleep.set()
    stop_event_ping.set()
    time.sleep(2)

exit_code, ping_output = output.get()
logging.info(f"thread ping exit code: {exit_code}")
logging.info(f"thread ping output length: {len(ping_output)}")

ssh_controller.disconnect()

License

GNU Lesser General Public License v2.1