Simple continuous deployment script

_git-to-public.py

'''
Name:           git-to-public
Description:    Simple continuous deployment script. Listens for pushes to
                Gitlab repositories. When there is a push to the master
                branch it clones the repo to the same folder as the script
                is in.

Author:         Koen Vendrik <[email protected]>
Date:           22/11/2014
License:        MIT

Usage:          1. Generate a SSH key on your server and add it to your Gitlab.
                2. Setup a hook for localhost:9000 on the repos you want to
                   copy to the script directory when there is a push to
                   the master branch.
                3. Start listening by starting the script:
                   python _git-to-public.py
                4. Done! Now when you push to the master branch in one of the
                   repos the script will clone it to the same folder as the
                   script is in.

Note:           If you want to use a copy of Gitlab that is on a different
                server (e.g. gitlab.com) then you should open up port <PORT>
                on your server so Gitlab can reach it.
'''

from BaseHTTPServer import BaseHTTPRequestHandler, HTTPServer
from os import path
from shutil import rmtree
from json import loads
from subprocess import call


HOST = '127.0.0.1'
PORT = 9000

# branch to listen on
# script clones if there is a push to this branch
BRANCH = 'master'


def rm_dir_if_exists(dir_name):
    if path.exists(dir_name) and path.isdir(dir_name):
        rmtree(dir_name)
        print '>> Removed ./'+dir_name+'/'


def process_hook_data(data):
    # only act if push was to the <BRANCH> branch
    if data['ref'] == 'refs/heads/'+BRANCH:
        repo_details = data['repository']

        # remove repo folder if it exists
        print '>> Checking if '+repo_details['name']+' already exists...'
        rm_dir_if_exists(repo_details['name'])

        # clone repo
        print '>> Cloning repo...'
        call('git clone -b '+BRANCH+' '+repo_details['url'], shell=True)
        print '>> Done.\n'


class VerbHandler(BaseHTTPRequestHandler):

    def do_POST(self):
        self.send_response(200)
        length = int(self.headers['Content-Length'])

        # get post data, parse as json
        data = loads(self.rfile.read(length).decode('utf-8'))
        process_hook_data(data)


if __name__ == '__main__':
    try:
        # start server and keep listening
        httpd = HTTPServer((HOST, PORT), VerbHandler)
        print '>> Listening on '+HOST+':'+str(PORT)+'\n'
        httpd.serve_forever()
    except KeyboardInterrupt:
        # stop server when ^C is pressed
        print '>> Stopping server...'
        httpd.server_close()