checkout-repos.py

#!/usr/bin/env python
import argparse
import subprocess
import os
import sys
import shlex
import time
import shutil

class cd:
    """Context manager for changing the current working directory"""
    def __init__(self, newPath):
        self.newPath = newPath

    def __enter__(self):
        self.savedPath = os.getcwd()
        os.chdir(self.newPath)

    def __exit__(self, etype, value, traceback):
        os.chdir(self.savedPath)

def shcmd(cmd, ignore_error=False):
    print 'Doing:', cmd
    ret = subprocess.call(cmd, shell=True)
    print 'Returned', ret, cmd
    if ignore_error == False and ret != 0:
        raise RuntimeError("Failed to execute {}. Return code:{}".format(
            cmd, ret))
    return ret


def prepare_dir(dirpath):
    "create parent dirs for path if necessary"
    if not os.path.exists(dirpath):
        os.makedirs(dirpath)


def is_git_repos(dirpath):
    return os.path.exists( os.path.join(dirpath, '.git') )


def checkout_commit(target_dir, repo_name, commit):
    """
    Clone the repository to the target directory if it is not there yet.
    Checkout the specific commit
    """
    prepare_dir(target_dir)
    repos_path = os.path.join(target_dir, repo_name)

    with cd(target_dir):
        if is_git_repos(repos_path) is False:
            if os.path.exists(repos_path):
                shutil.rmtree(repos_path)
            shcmd('git clone git@github.com:junhe/{}.git'.format(repo_name))

        with cd(repo_name):
            shcmd('git pull', ignore_error=True)
            shcmd('git checkout {}'.format(commit))

def _main():
    parser = argparse.ArgumentParser(
            description=""
            )
    parser.add_argument('--repo_name', action='store')
    parser.add_argument('--target_dir', action='store')
    parser.add_argument('--commit', action='store')
    args = parser.parse_args()

    argdic = vars(args)
    if not all( v for _,v in argdic.items() ):
        parser.print_help()
        exit(1)

    checkout_commit(target_dir=args.target_dir,
            commit=args.commit, repo_name=args.repo_name)

if __name__ == '__main__':
    _main()