CentOS fails to bootstrap using juju 1.24

[Gabriel Samfira]

Starting with commit #2436, centOS support has been broken.

http://paste.ubuntu.com/11799637/

This commit was meant to fix bug #1459250. So I will try to put as much context as possible here:

1) If by any chance we will decide to support another OS which is also at version 7, as long as it has a different codename like Jessie, it will simply be another entry under the same version. This is confusing for humans, I agree, but machines will not care. See bellow for alternative to avoid this confusion.

2) The way version detection is done now, is through reading /etc/os-release on modern Linux based systems. On CentOS 7, the contents of this file are as follows:

http://paste.ubuntu.com/11799653/

So VERSION_ID in that particular file is just "7".

3) We need to trust that the test has been written with valid sample data :). Changing the test so that it passes, but breaks the actual functionality is not a good thing.

Now, like I said, I agree that just a simple digit is confusing, but its technically correct. That is the actual "version" of the operating system, in the same way that 14.04 is the version nr for trusty. If we do not want to create confusion, we can determine the OS, then the version, create an internal map, look up that version inside that particular map. This can be done with minimal changes to what we already have. It just needs to be changed in the right place, while taking into account that we may support other operating systems that are redhat based in the future (Fedora for example).

[Curtis Hovey (sinzui)]

We cannot accept a juju version of just "7" is must be a string to differentiate itself from other series. So the code need to change to make centos7

[Gabriel Samfira (gabriel-samfira)]

Agreed, and I apologise for not thinking about this when I did the version detection for CentOS.

Point 3) is the one that I care about in this case :). It make it hard to trust tests if we change them to just pass but we break the actual functionality we are testing.