How to know if a paramiko SSH channel is disconnected?

Question

I'm desinging test cases in which I use paramiko for SSH connections. Test cases usually contain `paramiko.exec_command()` calls which I have a wrapper for (called `run_command()`). Here `self.ssh` is an intance of `paramiko.SSHClient()`. I use a decorator to check the ssh connection before each call. (`self.get_ssh()` negotiates the connection) ``` def check_connections(function): ''' A decorator to check SSH connections. ''' def deco(self, *args, **kwargs): if self.ssh is None: self.ssh = self.get_ssh() else: ret = getattr(self.ssh.get_transport(), 'is_active', None) if ret is None or (ret is not None and not ret()): self.ssh = self.get_ssh() return function(self, *args, **kwargs) return deco ``` ``` @check_connections def run_command(self, command): ''' Executes command via SSH. ''' stdin, stdout, stderr = self.ssh.exec_command(command) stdin.flush() stdin.channel.shutdown_write() ret = stdout.read() err = stderr.read() if ret: return ret elif err: return err else: return None ```…

Accepted Answer

In python, it's easier to ask for forgiveness than permission.

Wrap each call to `ssh.exec_command` like so:

```
try:
    ssh.exec_command('ls')
except socket.error as e:
    # Crap, it's closed. Perhaps reopen and retry?
```

How to know if a paramiko SSH channel is disconnected?

Solution

Problem