Stop installing pydistutils.cfg

Support for easy_install codepaths is increasingly broken, and now
putting allow-hosts in this file breaks most recent pip. Just stop
installing the file - people should be using pip anyway.

Change-Id: I0a6b2432f81d80fbcbb336403fe555003880fa9f

diskimage_builder/elements/pypi/README.rst

@@ -8,8 +8,7 @@ Inject a PyPI mirror
 
 Use a custom PyPI mirror to build images. The default is to bind mount one from
 ~/.cache/image-create/pypi/mirror into the build environment as mirror URL
-file:///tmp/pypi. The element temporarily overwrites /root/.pip.conf
-and .pydistutils.cfg to use it.
+file:///tmp/pypi. The element temporarily overwrites /root/.pip.conf to use it.
 
 When online, the official pypi.python.org pypi index is supplied as an
 extra-url, so uncached dependencies will still be available. When offline, only
@@ -21,9 +20,7 @@ DIB\_NO\_PYPI\_PIP to any non-empty value.
 To use an arbitrary mirror set DIB\_PYPI\_MIRROR\_URL=http[s]://somevalue/
 
 Additional mirrors can be added by exporting DIB\_PYPI\_MIRROR\_URL\_1=... etc.
-Only the one mirror can be used by easy-install, but since wheels need to be in
-the first mirror to be used, the last listed mirror is used as the pydistutils
-index. NB: The sort order for these variables is a simple string sort - if you
+NB: The sort order for these variables is a simple string sort - if you
 have more than 9 additional mirrors, some care will be needed.
 
 You can also set the number of retries that occur on failure by setting the

diskimage_builder/elements/pypi/post-install.d/00-unconfigure-pypi-mirror

@@ -11,10 +11,3 @@ if [ -e ~/.pip/pip.conf.orig ]; then
 else
     rm ~/.pip/pip.conf
 fi
-
-
-if [ -e ~/.pydistutils.cfg.orig ]; then
-    mv ~/.pydistutils.cfg{.orig,}
-else
-    rm ~/.pydistutils.cfg
-fi

diskimage_builder/elements/pypi/pre-install.d/04-configure-pypi-mirror

@@ -41,7 +41,6 @@ def main():
         indices = ['file:///tmp/pypi']
         print('WARNING: You are using the pypi element but no pypi mirror is '
               'defined via the PYPI_MIRROR_URL env variable')
-    easy_index = indices[-1]
     use_pypi_python_org = True
     if os.environ.get('DIB_OFFLINE'):
         use_pypi_python_org = False
@@ -61,10 +60,6 @@ def main():
             output.write('extra-index-url =\n')
             for index in indices[1:]:
                 output.write('    %s\n' % (index,))
-    with open(home + '/.pydistutils.cfg', 'wt') as output:
-        output.write('[easy_install]\n')
-        output.write('index_url = %s\n' % (easy_index,))
-        output.write('allow_hosts = %s\n' % (urlparse(easy_index).netloc,))
 
 
 def backup_configs(home):