gistfile1.py

#!/usr/bin/env python

import sys
import subprocess

colour_codes = {
    'none': '\033[0m',
    'red': '\033[91m',
    'green': '\033[92m',
    'yellow': '\033[93m',
}

def colour(c, text):
    return colour_codes[c] + text + colour_codes['none']

def git(args):
    git = subprocess.Popen(['git'] + args, stdout = subprocess.PIPE)
    return git.stdout.read().strip()

def git_diff(old, new):
    return git(['diff', '--name-only', '{0}..{1}'.format(old, new)])

def run_cmd(cmd, msg=None):
    if msg is not None:
        print msg
    return subprocess.Popen(cmd, stdout = subprocess.PIPE)

if __name__ == '__main__':
    for line in sys.stdin.xreadlines():
        old, new, ref = line.strip().split(' ')
        print colour('red', "old: {0} new: {1} ref: {2}".format(old, new, ref))

        lines = git_diff(old, new).split('\n')

        # check for changes, and perform any actions required
        if any("requirements.txt" in line for line in lines)
            run_cmd('date', "requirements.txt has changed")

        if any("/static/" in line for line in lines):
            run_cmd(['manage.py', 'collectstatic'], "Static files have changed")

        if any("/migrations/" in line for line in lines):
            run_cmd(['manage.py', 'migrate'], "New migrations have been added")

        # cleanup dead pyc files
        run_cmd(['find', '.' '-name', '\*.pyc', '-delete'], 'removing stale bytecode')

        # restart gunicorn
        run_cmd(['sudo', 'svc', '-d', '/etc/service/PROJECT_NAME'], "Stopping server")
        run_cmd(['sudo', 'svc', '-o', '/etc/service/PROJECT_NAME'], "Starting server")