virtualenv + pip self deployed

build.py

from __future__ import print_function
import sys
import shutil
import os
import subprocess


is_win = (sys.platform == 'win32')
req_file = "req.txt"
home_dir = os.path.dirname(os.path.abspath(__file__))
env_dir = os.path.join(home_dir, "env")
bin_dir = os.path.join(env_dir, "bin")
if is_win:
    bin_dir = os.path.join(env_dir, 'Scripts')
static_dir = os.path.join(home_dir, "cosima", "static")
VENV_VERSION = "12.0.7"
PYPI_VENV_BASE = "http://pypi.python.org/packages/source/v/virtualenv"
PYTHON = "python2"


def shellcmd(cmd, echo=True, cwd=None):
    """ Run 'cmd' in the shell and return its standard out.
    """
    cmd = cmd.split()
    if echo:
        print('[cmd] {0}'.format(cmd))
    if subprocess.call(cmd, cwd=cwd) != 0:
        print("Aborting...")
        sys.exit(1)


def virtualenv():
    dirname = 'virtualenv-' + VENV_VERSION
    tgz_file = dirname + '.tar.gz'

    # Fetch virtualenv from PyPI
    venv_url = PYPI_VENV_BASE + '/' + tgz_file
    shellcmd('wget {0}'.format(venv_url))

    # Untar
    shellcmd('tar xzf {0}'.format(tgz_file))

    # Create the initial env
    shellcmd('{0} {1}/virtualenv.py {2}'.format(PYTHON, dirname, env_dir))

    # Install the virtualenv package itself into the initial env
    shellcmd('{0}/pip install {1}'.format(bin_dir, tgz_file))

    # Cleanup
    shutil.rmtree(dirname)
    os.remove(tgz_file)


def main():
    print("Creating virtualenv...")
    virtualenv()

    print("Installing eggs...")
    shellcmd("{cmd} install -r {req}".format(
        cmd=os.path.join(bin_dir, "pip"),
        req=req_file))


if __name__ == "__main__":
    main()