Question

from fabric.api import env, sudo
def get_hostname():
    env.hosts = ['user@host_ip']
    env.passwords = {'user@host_ip': 'password'}
    hostname = run_cmd('hostname')
    print hostname


def run_cmd(cmd):
    return sudo(cmd)


if __name__ == '__main__':
    get_hostname()

This code is not working it is saying:

No hosts found. Please specify (single) host string for connection:

Answer 1

The function get_hostname will not be called unless you specify it in the fab arguments, calling it under if __name__ == '__main__' will not do what you think it does because a fabfile is not like a usual python script.

What you have to do is call your fabfile like this: fab get_hostname run_cmd and to have a more consistent error you can use require function like this:

from fabric.api import require


def run_cmd():
    require('hosts', provided_by=[get_hostname])