Fast Python Buildout Bootstrap

bootstrap.py

##############################################################################
#
# Copyright (c) 2006 Zope Foundation and Contributors.
# All Rights Reserved.
#
# This software is subject to the provisions of the Zope Public License,
# Version 2.1 (ZPL).  A copy of the ZPL should accompany this distribution.
# THIS SOFTWARE IS PROVIDED "AS IS" AND ANY AND ALL EXPRESS OR IMPLIED
# WARRANTIES ARE DISCLAIMED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
# WARRANTIES OF TITLE, MERCHANTABILITY, AGAINST INFRINGEMENT, AND FITNESS
# FOR A PARTICULAR PURPOSE.
#
##############################################################################
"""Bootstrap a buildout-based project

Simply run this script in a directory containing a buildout.cfg.
The script accepts buildout command-line options, so you can
use the -c option to specify an alternate configuration file.
"""

import os, shutil, sys, tempfile, urllib, urllib2, subprocess
from optparse import OptionParser

if sys.platform == 'win32':
    def quote(c):
        if ' ' in c:
            return '"%s"' % c  # work around spawn lamosity on windows
        else:
            return c
else:
    quote = str

# See zc.buildout.easy_install._has_broken_dash_S for motivation and comments.
stdout, stderr = subprocess.Popen(
    [sys.executable, '-Sc',
     'try:\n'
     '    import ConfigParser\n'
     'except ImportError:\n'
     '    print 1\n'
     'else:\n'
     '    print 0\n'],
    stdout=subprocess.PIPE, stderr=subprocess.PIPE).communicate()
has_broken_dash_S = bool(int(stdout.strip()))

# In order to be more robust in the face of system Pythons, we want to
# run without site-packages loaded.  This is somewhat tricky, in
# particular because Python 2.6's distutils imports site, so starting
# with the -S flag is not sufficient.  However, we'll start with that:
if not has_broken_dash_S and 'site' in sys.modules:
    # We will restart with python -S.
    args = sys.argv[:]
    args[0:0] = [sys.executable, '-S']
    args = map(quote, args)
    os.execv(sys.executable, args)
# Now we are running with -S.  We'll get the clean sys.path, import site
# because distutils will do it later, and then reset the path and clean
# out any namespace packages from site-packages that might have been
# loaded by .pth files.
clean_path = sys.path[:]
import site  # imported because of its side effects
sys.path[:] = clean_path
for k, v in sys.modules.items():
    if k in ('setuptools', 'pkg_resources') or (
        hasattr(v, '__path__') and
        len(v.__path__) == 1 and
        not os.path.exists(os.path.join(v.__path__[0], '__init__.py'))):
        # This is a namespace package.  Remove it.
        sys.modules.pop(k)

is_jython = sys.platform.startswith('java')

setuptools_source = 'http://peak.telecommunity.com/dist/ez_setup.py'
distribute_source = 'http://python-distribute.org/distribute_setup.py'


# parsing arguments
def normalize_to_url(option, opt_str, value, parser):
    if value:
        if '://' not in value:  # It doesn't smell like a URL.
            value = 'file://%s' % (
                urllib.pathname2url(
                    os.path.abspath(os.path.expanduser(value))),)
        if opt_str == '--download-base' and not value.endswith('/'):
            # Download base needs a trailing slash to make the world happy.
            value += '/'
    else:
        value = None
    name = opt_str[2:].replace('-', '_')
    setattr(parser.values, name, value)

usage = '''\
[DESIRED PYTHON FOR BUILDOUT] bootstrap.py [options]

Bootstraps a buildout-based project.

Simply run this script in a directory containing a buildout.cfg, using the
Python that you want bin/buildout to use.

Note that by using --setup-source and --download-base to point to
local resources, you can keep this script from going over the network.
'''

parser = OptionParser(usage=usage)
parser.add_option("-v", "--version", dest="version",
                          help="use a specific zc.buildout version")
parser.add_option("-d", "--distribute",
                   action="store_true", dest="use_distribute", default=False,
                   help="Use Distribute rather than Setuptools.")
parser.add_option("--setup-source", action="callback", dest="setup_source",
                  callback=normalize_to_url, nargs=1, type="string",
                  help=("Specify a URL or file location for the setup file. "
                        "If you use Setuptools, this will default to " +
                        setuptools_source + "; if you use Distribute, this "
                        "will default to " + distribute_source + "."))
parser.add_option("--download-base", action="callback", dest="download_base",
                  callback=normalize_to_url, nargs=1, type="string",
                  help=("Specify a URL or directory for downloading "
                        "zc.buildout and either Setuptools or Distribute. "
                        "Defaults to PyPI."))
parser.add_option("--eggs",
                  help=("Specify a directory for storing eggs.  Defaults to "
                        "a temporary directory that is deleted when the "
                        "bootstrap script completes."))
parser.add_option("-t", "--accept-buildout-test-releases",
                  dest='accept_buildout_test_releases',
                  action="store_true", default=False,
                  help=("Normally, if you do not specify a --version, the "
                        "bootstrap script and buildout gets the newest "
                        "*final* versions of zc.buildout and its recipes and "
                        "extensions for you.  If you use this flag, "
                        "bootstrap and buildout will get the newest releases "
                        "even if they are alphas or betas."))
parser.add_option("-c", None, action="store", dest="config_file",
                   help=("Specify the path to the buildout configuration "
                         "file to be used."))

options, args = parser.parse_args()

if options.eggs:
    eggs_dir = os.path.abspath(os.path.expanduser(options.eggs))
else:
    eggs_dir = tempfile.mkdtemp()

if options.setup_source is None:
    if options.use_distribute:
        options.setup_source = distribute_source
    else:
        options.setup_source = setuptools_source

if options.accept_buildout_test_releases:
    args.insert(0, 'buildout:accept-buildout-test-releases=true')

try:
    import pkg_resources
    import setuptools  # A flag.  Sometimes pkg_resources is installed alone.
    if not hasattr(pkg_resources, '_distribute'):
        raise ImportError
except ImportError:
    ez_code = urllib2.urlopen(
        options.setup_source).read().replace('\r\n', '\n')
    ez = {}
    exec ez_code in ez
    setup_args = dict(to_dir=eggs_dir, download_delay=0)
    if options.download_base:
        setup_args['download_base'] = options.download_base
    if options.use_distribute:
        setup_args['no_fake'] = True
        if sys.version_info[:2] == (2, 4):
            setup_args['version'] = '0.6.32'
    ez['use_setuptools'](**setup_args)
    if 'pkg_resources' in sys.modules:
        reload(sys.modules['pkg_resources'])
    import pkg_resources
    # This does not (always?) update the default working set.  We will
    # do it.
    for path in sys.path:
        if path not in pkg_resources.working_set.entries:
            pkg_resources.working_set.add_entry(path)

cmd = [quote(sys.executable),
       '-c',
       quote('from setuptools.command.easy_install import main; main()'),
       '-mqNxd',
       quote(eggs_dir)]

if not has_broken_dash_S:
    cmd.insert(1, '-S')

find_links = options.download_base
if not find_links:
    find_links = os.environ.get('bootstrap-testing-find-links')
if not find_links and options.accept_buildout_test_releases:
    find_links = 'http://downloads.buildout.org/'
if find_links:
    cmd.extend(['-f', quote(find_links)])

if options.use_distribute:
    setup_requirement = 'distribute'
else:
    setup_requirement = 'setuptools'
ws = pkg_resources.working_set
setup_requirement_path = ws.find(
    pkg_resources.Requirement.parse(setup_requirement)).location
env = dict(
    os.environ,
    PYTHONPATH=setup_requirement_path)

requirement = 'zc.buildout'
version = options.version
if version is None and not options.accept_buildout_test_releases:
    # Figure out the most recent final version of zc.buildout.
    import setuptools.package_index
    _final_parts = '*final-', '*final'

    def _final_version(parsed_version):
        for part in parsed_version:
            if (part[:1] == '*') and (part not in _final_parts):
                return False
        return True
    index = setuptools.package_index.PackageIndex(
        search_path=[setup_requirement_path])
    if find_links:
        index.add_find_links((find_links,))
    req = pkg_resources.Requirement.parse(requirement)
    if index.obtain(req) is not None:
        best = []
        bestv = None
        for dist in index[req.project_name]:
            distv = dist.parsed_version
            if distv >= pkg_resources.parse_version('2dev'):
                continue
            if _final_version(distv):
                if bestv is None or distv > bestv:
                    best = [dist]
                    bestv = distv
                elif distv == bestv:
                    best.append(dist)
        if best:
            best.sort()
            version = best[-1].version

if version:
    requirement += '=='+version
else:
    requirement += '<2dev'

cmd.append(requirement)

if is_jython:
    import subprocess
    exitcode = subprocess.Popen(cmd, env=env).wait()
else:  # Windows prefers this, apparently; otherwise we would prefer subprocess
    exitcode = os.spawnle(*([os.P_WAIT, sys.executable] + cmd + [env]))
if exitcode != 0:
    sys.stdout.flush()
    sys.stderr.flush()
    print ("An error occurred when trying to install zc.buildout. "
           "Look above this message for any errors that "
           "were output by easy_install.")
    sys.exit(exitcode)

ws.add_entry(eggs_dir)
ws.require(requirement)
import zc.buildout.buildout

# If there isn't already a command in the args, add bootstrap
if not [a for a in args if '=' not in a]:
    args.append('bootstrap')


# if -c was provided, we push it back into args for buildout's main function
if options.config_file is not None:
    args[0:0] = ['-c', options.config_file]

zc.buildout.buildout.main(args)
if not options.eggs:  # clean up temporary egg directory
    shutil.rmtree(eggs_dir)

buildout.cfg

[buildout]
parts =

Makefile

defaults: bootstrap buildout

bootstrap:
	python bootstrap.py -d

buildout:
	bin/buildout

clean:
	git clean -xdf