Revert "dpkg-divert" and change PATH instead

[yosifkit]

Reverting and changing #131 which was the fix for #129. Also fix some spaces to tabs like the rest of the file.

Fix #133, fix #134.

[JayH5]

FWIW, these images already have /usr/local/bin in their PATHs before /usr/bin. debian:jessie, buildpack-deps:jessie and buildpackdeps-wheezy all have a (very standard) PATH of /usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin. But I guess you're wanting to make that explicit...

[tianon]

@JayH5 indeed, the point is to be 100% explicit to ensure that by default, python resolves to what we've created/added no matter what happens 👍

LGTM

[darabos]

Would it make sense to add automated tests for this issue? Python is one of the most popular images: an issue like this has a fairly large impact.

[yosifkit]

@darabos, that sounds like a great idea. Do you have an idea of what would be the best indicator? Maybe just test that /usr/bin/python --version is Python 2.7.9? I am not sure what we are trying to test for so I am unsure where the test needs to fail.

We do have tests that we run from travis that are also part of accepting it into official-images for building and pushing to the hub: https://github.com/docker-library/official-images/tree/master/test.

[darabos]

Sorry, I'm just a clueless user with no deep understanding of the issue. We just experienced that apt-get install -y openjdk-7-jre was failing.

Thanks for the link, I never knew about those tests! It looks like debian-apt-get/container.sh already tests apt-get install with a toy package. Would it be crazy to test with a more substantial package, like openjdk-7-jre?

Just testing /usr/bin/python --version like you propose would definitely be faster and more reliable. 👍