Update script for split-environment Puppetmaster module dirs

#!/usr/bin/env python

import sys
import os
import os.path
import logging
import subprocess

ENV_DIR = "environments"
MODULES = ['core', 'site']

logging.basicConfig(format="%(message)s", level='INFO')
log = logging.getLogger('puppet-refresh')

def needs_pull(path, branch='master'):
    output = subprocess.check_output(['git', '--git-dir=.git', 'ls-remote', '--heads', 'origin', branch]).strip()
    latest_commit, branchinfo = output.split()
    current_commit = subprocess.check_output(['git', '--git-dir=.git', 'ls-remote', '--heads', 'origin', branch]).strip()
    return current_commit != latest_commit

def clone(url, path):
    try:
        output = subprocess.check_output(['git', 'clone', url, path])
        log.debug(output)
    except subprocess.CalledProcessError, e:
        log.error("Error in git clone: %s" % e.output)
        sys.exit(1)

def checkout(path, branch):
    try:
        output = subprocess.check_output(['git', 'rev-parse', '--abbrev-ref', 'HEAD'], cwd=path).strip()
        if(output != branch):
            output = subprocess.check_output(['git', 'checkout', branch], cwd=path)
            log.debug(output)
    except subprocess.CalledProcessError, e:
        log.error("Error in git checkout: %s" % e.output)
        sys.exit(1)

def pull(path):
    try:
        output = subprocess.check_output(['git', 'rev-parse', '--abbrev-ref', 'HEAD'], cwd=path).strip()
        if(needs_pull(output)):
            output = subprocess.check_output(['git', 'pull'], cwd=path)
            log.debug(output)
    except subprocess.CalledProcessError, e:
        log.error("Error in git pull: %s" % e.output)
        sys.exit(1)

def fetch(path):
    try:
        output = subprocess.check_output(['git', 'fetch'], cwd=path)
        log.debug(output)
    except subprocess.CalledProcessError, e:
        log.error("Error in git fetch: %s" % e.output)
        sys.exit(1)

def main():
    selected_branch, selected_module = None, None
    if(len(sys.argv) == 2):
        selected_branch = sys.argv[1]
    elif(len(sys.argv) == 3):
        selected_branch, selected_module = sys.argv[1:]

    for environment in os.listdir(ENV_DIR):
        if(environment == 'common'):
            continue
        elif(not os.path.isdir(os.path.join(ENV_DIR, environment))):
            continue
        elif(selected_branch and selected_branch != environment):
            continue

        log.info("Updating module %s for %s..." % (selected_module, environment))
        for module in MODULES:
            if(selected_module and selected_module != module):
                continue
            module_path = os.path.join(ENV_DIR, environment, module)
            if(os.path.exists(module_path)):
                log.info("Refreshing %s" % module)
                fetch(module_path)
                checkout(module_path, environment)
                pull(module_path)
            else:
                log.info("Cloning %s" % module)
                clone("git@example.com:puppet/%s.git" % module, module_path)
                checkout(module_path, environment)

if __name__ == "__main__":
    main()