Pinning dependencies versions in buildout

pinversions.py

import zc.buildout.easy_install
import zc.recipe.egg
import os
import os.path
import sys
import fileinput
import pkg_resources

class PinVersions:
    """
    Recipe for generation of pinversions script
    """

    def __init__(self, buildout, name, options):
        self.packages = buildout['buildout']['develop'].split()
        self.bindir = buildout['buildout']['bin-directory']
        self.egg = zc.recipe.egg.Scripts(buildout, name, options)

    def install(self):
        _, ws = self.egg.working_set(['recipes'])
        return zc.buildout.easy_install.scripts(
            [('pinversions', 'recipes.pinversions', 'pinversions'),
             ('dumpversions', 'recipes.pinversions', 'dumpversions')],
            ws, sys.executable, self.bindir,
            arguments='packages=%r' % self.packages)

    update = install


def _find_version():
    if len(sys.argv) < 2:
        return os.popen('git describe').read().strip()
    else:
        return sys.argv[1]

def pinversions(packages):
    """
    pin versions of our packages to command line argument or
    'git describe' if command line argument isn't given
    """
    version = _find_version()

    # change version in setup.py files
    for p in packages:
        setup_script = os.path.join(p, "setup.py")
        for line in fileinput.input(setup_script, inplace=1):
            if line.startswith("version"):
                sys.stdout.write("version = '%s'\n" % version)
            else:
                sys.stdout.write(line)

    # change version in buildout.cfg
    for line in fileinput.input("buildout.cfg", inplace=1):
        if line.startswith("kgp-version"):
            sys.stdout.write("kgp-version = %s\n" % version)
        else:
            sys.stdout.write(line)

def dumpversions(packages):
    version = _find_version()
    devel_pkgs = []
    for p in packages:
        devel_pkgs.append(os.path.realpath(p))
    for dist in pkg_resources.working_set:
        if any((dist.location.startswith(d) for d in devel_pkgs)):
            v = version
        else:
            v = dist.version
            print "%s = %s" % (dist.project_name, v)