Add ez_setup.py to bootstrap recent setuptools.

Author: Peter Amstutz

ez_setup.py

@@ -0,0 +1,332 @@
+#!/usr/bin/env python
+"""Bootstrap setuptools installation
+
+To use setuptools in your package's setup.py, include this
+file in the same directory and add this to the top of your setup.py::
+
+    from ez_setup import use_setuptools
+    use_setuptools()
+
+To require a specific version of setuptools, set a download
+mirror, or use an alternate download directory, simply supply
+the appropriate options to ``use_setuptools()``.
+
+This file can also be run as a script to install or upgrade setuptools.
+"""
+import os
+import shutil
+import sys
+import tempfile
+import zipfile
+import optparse
+import subprocess
+import platform
+import textwrap
+import contextlib
+
+from distutils import log
+
+try:
+    from site import USER_SITE
+except ImportError:
+    USER_SITE = None
+
+DEFAULT_VERSION = "3.4.1"
+DEFAULT_URL = "https://pypi.python.org/packages/source/s/setuptools/"
+
+def _python_cmd(*args):
+    """
+    Return True if the command succeeded.
+    """
+    args = (sys.executable,) + args
+    return subprocess.call(args) == 0
+
+
+def _install(archive_filename, install_args=()):
+    with archive_context(archive_filename):
+        # installing
+        log.warn('Installing Setuptools')
+        if not _python_cmd('setup.py', 'install', *install_args):
+            log.warn('Something went wrong during the installation.')
+            log.warn('See the error message above.')
+            # exitcode will be 2
+            return 2
+
+
+def _build_egg(egg, archive_filename, to_dir):
+    with archive_context(archive_filename):
+        # building an egg
+        log.warn('Building a Setuptools egg in %s', to_dir)
+        _python_cmd('setup.py', '-q', 'bdist_egg', '--dist-dir', to_dir)
+    # returning the result
+    log.warn(egg)
+    if not os.path.exists(egg):
+        raise IOError('Could not build the egg.')
+
+
+def get_zip_class():
+    """
+    Supplement ZipFile class to support context manager for Python 2.6
+    """
+    class ContextualZipFile(zipfile.ZipFile):
+        def __enter__(self):
+            return self
+        def __exit__(self, type, value, traceback):
+            self.close
+    return zipfile.ZipFile if hasattr(zipfile.ZipFile, '__exit__') else \
+        ContextualZipFile
+
+
+@contextlib.contextmanager
+def archive_context(filename):
+    # extracting the archive
+    tmpdir = tempfile.mkdtemp()
+    log.warn('Extracting in %s', tmpdir)
+    old_wd = os.getcwd()
+    try:
+        os.chdir(tmpdir)
+        with get_zip_class()(filename) as archive:
+            archive.extractall()
+
+        # going in the directory
+        subdir = os.path.join(tmpdir, os.listdir(tmpdir)[0])
+        os.chdir(subdir)
+        log.warn('Now working in %s', subdir)
+        yield
+
+    finally:
+        os.chdir(old_wd)
+        shutil.rmtree(tmpdir)
+
+
+def _do_download(version, download_base, to_dir, download_delay):
+    egg = os.path.join(to_dir, 'setuptools-%s-py%d.%d.egg'
+                       % (version, sys.version_info[0], sys.version_info[1]))
+    if not os.path.exists(egg):
+        archive = download_setuptools(version, download_base,
+                                      to_dir, download_delay)
+        _build_egg(egg, archive, to_dir)
+    sys.path.insert(0, egg)
+
+    # Remove previously-imported pkg_resources if present (see
+    # https://bitbucket.org/pypa/setuptools/pull-request/7/ for details).
+    if 'pkg_resources' in sys.modules:
+        del sys.modules['pkg_resources']
+
+    import setuptools
+    setuptools.bootstrap_install_from = egg
+
+
+def use_setuptools(version=DEFAULT_VERSION, download_base=DEFAULT_URL,
+        to_dir=os.curdir, download_delay=15):
+    to_dir = os.path.abspath(to_dir)
+    rep_modules = 'pkg_resources', 'setuptools'
+    imported = set(sys.modules).intersection(rep_modules)
+    try:
+        import pkg_resources
+    except ImportError:
+        return _do_download(version, download_base, to_dir, download_delay)
+    try:
+        pkg_resources.require("setuptools>=" + version)
+        return
+    except pkg_resources.DistributionNotFound:
+        return _do_download(version, download_base, to_dir, download_delay)
+    except pkg_resources.VersionConflict as VC_err:
+        if imported:
+            msg = textwrap.dedent("""
+                The required version of setuptools (>={version}) is not available,
+                and can't be installed while this script is running. Please
+                install a more recent version first, using
+                'easy_install -U setuptools'.
+
+                (Currently using {VC_err.args[0]!r})
+                """).format(VC_err=VC_err, version=version)
+            sys.stderr.write(msg)
+            sys.exit(2)
+
+        # otherwise, reload ok
+        del pkg_resources, sys.modules['pkg_resources']
+        return _do_download(version, download_base, to_dir, download_delay)
+
+def _clean_check(cmd, target):
+    """
+    Run the command to download target. If the command fails, clean up before
+    re-raising the error.
+    """
+    try:
+        subprocess.check_call(cmd)
+    except subprocess.CalledProcessError:
+        if os.access(target, os.F_OK):
+            os.unlink(target)
+        raise
+
+def download_file_powershell(url, target):
+    """
+    Download the file at url to target using Powershell (which will validate
+    trust). Raise an exception if the command cannot complete.
+    """
+    target = os.path.abspath(target)
+    cmd = [
+        'powershell',
+        '-Command',
+        "(new-object System.Net.WebClient).DownloadFile(%(url)r, %(target)r)" % vars(),
+    ]
+    _clean_check(cmd, target)
+
+def has_powershell():
+    if platform.system() != 'Windows':
+        return False
+    cmd = ['powershell', '-Command', 'echo test']
+    devnull = open(os.path.devnull, 'wb')
+    try:
+        try:
+            subprocess.check_call(cmd, stdout=devnull, stderr=devnull)
+        except Exception:
+            return False
+    finally:
+        devnull.close()
+    return True
+
+download_file_powershell.viable = has_powershell
+
+def download_file_curl(url, target):
+    cmd = ['curl', url, '--silent', '--output', target]
+    _clean_check(cmd, target)
+
+def has_curl():
+    cmd = ['curl', '--version']
+    devnull = open(os.path.devnull, 'wb')
+    try:
+        try:
+            subprocess.check_call(cmd, stdout=devnull, stderr=devnull)
+        except Exception:
+            return False
+    finally:
+        devnull.close()
+    return True
+
+download_file_curl.viable = has_curl
+
+def download_file_wget(url, target):
+    cmd = ['wget', url, '--quiet', '--output-document', target]
+    _clean_check(cmd, target)
+
+def has_wget():
+    cmd = ['wget', '--version']
+    devnull = open(os.path.devnull, 'wb')
+    try:
+        try:
+            subprocess.check_call(cmd, stdout=devnull, stderr=devnull)
+        except Exception:
+            return False
+    finally:
+        devnull.close()
+    return True
+
+download_file_wget.viable = has_wget
+
+def download_file_insecure(url, target):
+    """
+    Use Python to download the file, even though it cannot authenticate the
+    connection.
+    """
+    try:
+        from urllib.request import urlopen
+    except ImportError:
+        from urllib2 import urlopen
+    src = dst = None
+    try:
+        src = urlopen(url)
+        # Read/write all in one block, so we don't create a corrupt file
+        # if the download is interrupted.
+        data = src.read()
+        dst = open(target, "wb")
+        dst.write(data)
+    finally:
+        if src:
+            src.close()
+        if dst:
+            dst.close()
+
+download_file_insecure.viable = lambda: True
+
+def get_best_downloader():
+    downloaders = [
+        download_file_powershell,
+        download_file_curl,
+        download_file_wget,
+        download_file_insecure,
+    ]
+
+    for dl in downloaders:
+        if dl.viable():
+            return dl
+
+def download_setuptools(version=DEFAULT_VERSION, download_base=DEFAULT_URL,
+        to_dir=os.curdir, delay=15, downloader_factory=get_best_downloader):
+    """
+    Download setuptools from a specified location and return its filename
+
+    `version` should be a valid setuptools version number that is available
+    as an egg for download under the `download_base` URL (which should end
+    with a '/'). `to_dir` is the directory where the egg will be downloaded.
+    `delay` is the number of seconds to pause before an actual download
+    attempt.
+
+    ``downloader_factory`` should be a function taking no arguments and
+    returning a function for downloading a URL to a target.
+    """
+    # making sure we use the absolute path
+    to_dir = os.path.abspath(to_dir)
+    zip_name = "setuptools-%s.zip" % version
+    url = download_base + zip_name
+    saveto = os.path.join(to_dir, zip_name)
+    if not os.path.exists(saveto):  # Avoid repeated downloads
+        log.warn("Downloading %s", url)
+        downloader = downloader_factory()
+        downloader(url, saveto)
+    return os.path.realpath(saveto)
+
+def _build_install_args(options):
+    """
+    Build the arguments to 'python setup.py install' on the setuptools package
+    """
+    return ['--user'] if options.user_install else []
+
+def _parse_args():
+    """
+    Parse the command line for options
+    """
+    parser = optparse.OptionParser()
+    parser.add_option(
+        '--user', dest='user_install', action='store_true', default=False,
+        help='install in user site package (requires Python 2.6 or later)')
+    parser.add_option(
+        '--download-base', dest='download_base', metavar="URL",
+        default=DEFAULT_URL,
+        help='alternative URL from where to download the setuptools package')
+    parser.add_option(
+        '--insecure', dest='downloader_factory', action='store_const',
+        const=lambda: download_file_insecure, default=get_best_downloader,
+        help='Use internal, non-validating downloader'
+    )
+    parser.add_option(
+        '--version', help="Specify which version to download",
+        default=DEFAULT_VERSION,
+    )
+    options, args = parser.parse_args()
+    # positional arguments are ignored
+    return options
+
+def main():
+    """Install or upgrade setuptools and EasyInstall"""
+    options = _parse_args()
+    archive = download_setuptools(
+        version=options.version,
+        download_base=options.download_base,
+        downloader_factory=options.downloader_factory,
+    )
+    return _install(archive, _build_install_args(options))
+
+if __name__ == '__main__':
+    sys.exit(main())

setup.py

@@ -2,9 +2,13 @@
 
 import os
 import sys
-import setuptools.command.egg_info as egg_info_cmd
 import shutil
 
+import ez_setup
+ez_setup.use_setuptools(version="18.2")
+
+import setuptools.command.egg_info as egg_info_cmd
+
 from setuptools import setup, find_packages
 
 SETUP_DIR = os.path.dirname(__file__)