How to use Python modules over Paramiko (SSH)?

Python modules cannot be directly executed on remote servers over SSH since SSH only provides limited functionality for remote execution. However, you can work around this limitation using several approaches to run Python code remotely and retrieve results.

Method 1: Execute Remote Scripts via SSH

The most straightforward approach is to execute a Python script on the remote server and capture the output ?

import paramiko

# Create SSH client
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())

# Connect to remote server
ssh.connect('remote_host', username='user', password='password')

# Execute Python script remotely
stdin, stdout, stderr = ssh.exec_command('python3 /path/to/remote_script.py')

# Read output
output = stdout.read().decode('utf-8')
error = stderr.read().decode('utf-8')

print("Output:", output)
print("Error:", error)

ssh.close()

Reading Results from Files

For complex operations, you can write results to a file and then read it back ?

import paramiko

ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect('remote_host', username='user', password='password')

# Execute script that writes to file
ssh.exec_command('python3 /path/to/script.py > /tmp/result.txt')

# Read the result file
stdin, stdout, stderr = ssh.exec_command('cat /tmp/result.txt')
result = stdout.read().decode('utf-8')

print("Result from file:", result)
ssh.close()

Method 2: Using Pyro4 for Remote Objects

Pyro4 (Python Remote Objects) enables seamless communication between Python objects across networks ?

# Server side (remote_server.py)
import Pyro4

@Pyro4.expose
class Calculator:
    def add(self, a, b):
        return a + b
    
    def multiply(self, a, b):
        return a * b

daemon = Pyro4.Daemon()
uri = daemon.register(Calculator)
print("Calculator URI:", uri)
daemon.requestLoop()

# Client side (local_client.py)
import Pyro4

# Connect to remote object
calculator = Pyro4.Proxy("PYRO:Calculator@remote_host:port")

# Use remote methods as if they were local
result = calculator.add(5, 3)
print("Remote calculation result:", result)

Method 3: File Transfer with SFTP

You can transfer Python modules to the remote server and execute them ?

import paramiko

# Create SFTP connection
transport = paramiko.Transport(('remote_host', 22))
transport.connect(username='user', password='password')
sftp = paramiko.SFTPClient.from_transport(transport)

# Upload local module to remote server
sftp.put('/local/path/my_module.py', '/remote/path/my_module.py')

# Execute the uploaded module
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
ssh.connect('remote_host', username='user', password='password')

stdin, stdout, stderr = ssh.exec_command('python3 /remote/path/my_module.py')
output = stdout.read().decode('utf-8')

print("Remote execution output:", output)

sftp.close()
transport.close()
ssh.close()

Comparison

Conclusion

Use SSH script execution for simple remote tasks and Pyro4 for complex distributed applications requiring frequent remote method calls. Choose SFTP when you need to transfer and execute large Python modules remotely.