linux - Running process of remote SSH server in the background using Python Paramiko

Question

I am finding hard to run a process on a remote SSH server at background using Paramiko. I used :

stdin, stdout, stderr = ssh.exec_command('executefile.py &') 

and found that no process of executefile.py was found running.

Then I tried using other way as including a backward slash:

stdin, stdout, stderr = ssh.exec_command('executefile.py &') 

This method worked. There was an instance running on machine but no surprise, it was not running at background. I could come to know as it is not running at background as when code stuck at second line after this code. It was

all_inf = stdout.readlines()

Now code was not going beyond above line unless the process of the script was killed.

I am learning Paramiko, any help is appreciated.

Answer 1

I've tried all the methods described here and here without success, and finally realized that you need to use channels instead of using the SSHClient directly for calling exec_command (this does not work in background):

client = paramiko.SSHClient()
client.connect(ip_address, username='root', pkey=paramiko_key, timeout=5)
client.exec_command('python script.py > /dev/null 2>&1 &')

You should create and use a channel, this works in background:

client = paramiko.SSHClient()
client.connect(ip_address, username='root', pkey=paramiko_key, timeout=5)
transport = client.get_transport()
channel = transport.open_session()
channel.exec_command('python script.py > /dev/null 2>&1 &')

So nohup, dtach, screen, etc, are actually not necessary.