fabfile.py

#!/usr/bin/python

from fabric.api import local, env, puts, run, require, cd, put, prefix
from fabric.decorators import parallel

def yummy():
    host_list = [
        (['localhost'], '/Users/username/private_key')
    ]
    env.upg_command = 'sudo apt-get install bash'
    setup_hosts(host_list)

def appy():
    host_list = [
        (['localhost'], '/Users/username/private_key')
    ]
    env.upg_command = 'yum update bash'
    setup_hosts(host_list)

def setup_hosts(host_list):
    for hinfo in host_list:
        hosts, key = hinfo
        env.key_filename = key
        env.hosts = hosts

@parallel
def upgrade_bash():
    run(env.upg_command)