Several people have popped up in IRC recently with failures in these
elements. Without Python 2.7 available in the image they are
unsupported (OpenStack hasn't supported it for a long time). Remove
these to avoid further confusion.
The centos/centos7 DISTRO split that has happened with centos-minimal
is unfortunate but I don't think it helps to rename centos7/rhel7 ATM.
To summarise; DISTRO=centos7 means image based build,
DISTRO=centos && DIB_RELEASE=7 means the minimal build.
In the future, I think it is important that the minimal builds and
image builds set the same DISTRO. This reflects that "upper" layers
shouldn't care about the exact building of the lower layers. I see
CentOS 8 going one of two ways
1) the changes are so significant, we start separate centos8 /
centos8-minimal elements. They both set DISTRO=centos8 (and
DIB_RELEASE to point-release maybe?). This means we have to update
all "if DISTRO == centos || DISTRO == centos7" branches to also check
for "centos8". Evenually (!) "centos" goes away for versioned DISTRO
only
2) we restore centos element with DISTRO=centos and DIB_RELEASE=8, and
centos-minimal remains the same. This means we have to audit all "if
DISTRO == centos" calls to make sure they're appropriate for version 8
(stick a "&& DIB_RELEASE=7" on them all basically).
I'm not sure we can fully decide until we start to see excatly how the
distro switching/matching bits look, but (2) is consistent with Ubuntu
and probably the preferred solution.
Some "rhel" parts have been cleaned up. More could be done in
rhel-common, but given our lack of coverage of that I'd prefer to
leave it for now.
Change-Id: I6ea784116ef59ca22878c8512c963f29c815a00a
Currently we have all our elements and library files in a top-level
directory and install them into
<root>/share/diskimage-builder/[elements|lib] (where root is either /
or the root of a virtualenv).
The problem with this is that editable/development installs (pip -e)
do *not* install data_files. Thus we have no canonical location to
look for elements -- leading to the various odd things we do such as a
whole bunch of guessing at the top of disk-image-create and having a
special test-loader in tests/test_elements.py so we can run python
unit tests on those elements that have it.
data_files is really the wrong thing to use for what are essentially
assets of the program. data_files install works well for things like
config-files, init.d files or dropping documentation files.
By moving the elements under the diskimage_builder package, we always
know where they are relative to where we import from. In fact,
pkg_resources has an api for this which we wrap in the new
diskimage_builder/paths.py helper [1].
We use this helper to find the correct path in the couple of places we
need to find the base-elements dir, and for the paths to import the
library shell functions.
Elements such as svc-map and pkg-map include python unit-tests, which
we do not need tests/test_elements.py to special-case load any more.
They just get found automatically by the normal subunit loader.
I have a follow-on change (I69ca3d26fede0506a6353c077c69f735c8d84d28)
to move disk-image-create to a regular python entry-point.
Unfortunately, this has to move to work with setuptools. You'd think
a symlink under diskimage_builder/[elements|lib] would work, but it
doesn't.
[1] this API handles stuff like getting files out of .zip archive
modules, which we don't do. Essentially for us it's returning
__file__.
Change-Id: I5e3e3c97f385b1a4ff2031a161a55b231895df5b
