Subprocess on remote server
You should use pexpect
or paramiko
to connect to remote machine,then spawn a child ,and then run subprocess
to achieve what you want.
Why make it so complicated? Here's what I suggest:
1) Create a ssh config section in your ~/.ssh/config file:
Host myserver
HostName 50.50.50.12 (fill in with your server's ip)
Port xxxx (optional)
User me (your username for server)
2) If you have generated your ssh keypair do it now (with ssh-keygen). Then upload with:
$ ssh-copy-id myserver
3) Now you can use subprocess with ssh. For example, to capture output, I call:
result = subprocess.check_output(['ssh', 'myserver', 'cat', 'somefile'])
Simple, robust, and the only time a password is needed is when you copy the public key to the server.
BTW, you code will probably work just fine as well using these steps.
One way is to create a public key, put it on the server, and do ssh -i /path/to/pub/key user@host
or use paramiko like this:
import paramiko
import getpass
ssh = paramiko.SSHClient()
ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())
p = getpass.getpass()
ssh.connect('hostname', username='user', password=p)
stdin, stdout, stderr = ssh.exec_command('ls')
print stdout.readlines()
ssh.close()
Here's what I did when encountering this issue before:
- Set up your ssh keys for access to the server.
- Set up an alias for the server you're accessing. Below I'll call it
remote_server
. Put the following two lines at the end of
~/.bash_profile
.eval $(ssh-agent -s) ssh-add
Now every time you start your shell, you will be prompted for a passphrase. By entering it, you will authenticate your ssh keys and put them 'in hand' at the start of your bash session. For the remainder of your session you will be able to run commands like
ssh remote_server ls
without being prompted for a passphrase. Here ls
will run on the remote server and return the results to you. Likewise your python script should run without password prompt interruption if you execute it from the shell.
You'll also be able to ssh to the server just by typing ssh remote_server
without having to enter your username or password every time.
The upside to doing it this way is that you should be doing this anyway to avoid password annoyances and remembering funky server names :) Also you don't have to worry about having passwords saved anywhere in your script. The only potential downside is that if you want to share the python script with others, they'll have to do this configuring as well (which they should anyway).