ApplyLayer exit status 1 stdout: stderr: mkdir XXX: file exists

[goldmann]

In a special case where we add/remove directories and files and create a new files instead of them with symlinks, squashing fails.

2016-08-31 09:21:04,208 - atomic_reactor.plugins.squash - DEBUG - Moving unmodified layer '47eed7a8ea3f131e9281ae09fcbfb0041872fd8b74a048f1c739302c8148505d'...
2016-08-31 09:21:04,209 - atomic_reactor.plugins.squash - DEBUG - Reading JSON metadata file '/tmp/docker-squash-qIEDpw/old/5e1910ede4695eb330b6e2c9fed29944f06c5798ad49c6d13a7d60ab09ca89b9/json'...
2016-08-31 09:21:04,209 - atomic_reactor.plugins.squash - INFO - New squashed image ID is 2ffce21bb64dc3c32b385ee916fe82a3d2d5a6788c41b4c2316ea61697c254dd
2016-08-31 09:21:04,210 - atomic_reactor.plugins.squash - DEBUG - Generating tar archive for the squashed image...
2016-08-31 09:21:05,252 - atomic_reactor.plugins.squash - DEBUG - Archive generated
2016-08-31 09:21:05,252 - atomic_reactor.plugins.squash - INFO - Image available at '/tmp/tmpYrpS4t/image.tar'
2016-08-31 09:21:05,252 - atomic_reactor.plugins.squash - DEBUG - Generating tar archive for the squashed image...
2016-08-31 09:21:06,300 - atomic_reactor.plugins.squash - DEBUG - Archive generated
2016-08-31 09:21:06,300 - atomic_reactor.plugins.squash - DEBUG - Loading squashed image...
2016-08-31 09:22:10,414 - atomic_reactor.plugins.squash - DEBUG - Cleaning up /tmp/docker-squash-qIEDpw temporary directory
2016-08-31 09:22:10,855 - atomic_reactor.plugin - DEBUG - Traceback (most recent call last):
  File "/usr/lib/python2.7/site-packages/atomic_reactor/plugin.py", line 211, in run
    plugin_response = plugin_instance.run()
  File "/usr/lib/python2.7/site-packages/atomic_reactor/plugins/prepub_squash.py", line 97, in run
    tag=self.tag, output_path=metadata["path"], load_image=True).run()
  File "/usr/lib/python2.7/site-packages/docker_squash/squash.py", line 59, in run
    return self.squash(image)
  File "/usr/lib/python2.7/site-packages/docker_squash/squash.py", line 92, in squash
    image.load_squashed_image()
  File "/usr/lib/python2.7/site-packages/docker_squash/image.py", line 233, in load_squashed_image
    self._load_image(self.new_image_dir)
  File "/usr/lib/python2.7/site-packages/docker_squash/image.py", line 278, in _load_image
    self.docker.load_image(f)
  File "/usr/lib/python2.7/site-packages/docker/api/image.py", line 153, in load_image
    self._raise_for_status(res)
  File "/usr/lib/python2.7/site-packages/docker/client.py", line 146, in _raise_for_status
    raise errors.APIError(e, response, explanation=explanation)
APIError: 500 Server Error: Internal Server Error ("ApplyLayer exit status 1 stdout:  stderr: mkdir /etc/systemd/system: file exists")

This can be reproduced with this simple Dockerfile:

FROM busybox:1.24
RUN mkdir -p /etc/systemd/system/multi-user.target.wants
RUN mkdir -p /etc/systemd/system/default.target.wants
RUN touch /etc/systemd/system/multi-user.target.wants/remote-fs.target
RUN touch /etc/systemd/system/default.target.wants/remote-fs.target
# End of preparations, going to squash from here
RUN find /etc/systemd/system/* '!' -name '*.wants' | xargs rm -rvf
RUN rmdir -v /etc/systemd/system/multi-user.target.wants && mkdir /etc/systemd/system/container-ipa.target.wants && ln -s /etc/systemd/system/container-ipa.target.wants /etc/systemd/system/multi-user.target.wants
RUN ln -s /etc/group /etc/systemd/system/default.target
RUN ln -s /etc/group /etc/systemd/system/container-ipa.target.wants/ipa-server-configure-first.service
RUN echo "/etc/systemd/system" > /etc/volume-data-list
RUN set -e ; cd / ; mkdir /data-template ; cat /etc/volume-data-list | while read i ; do echo $i ; if [ -e $i ] ; then tar cf - .$i | ( cd /data-template && tar xf - ) ; fi ; mkdir -p $( dirname $i ) ; if [ "$i" == /var/log/ ] ; then mv /var/log /var/log-removed ; else rm -rf $i ; fi ; ln -sf /data$i $i ; done