We somewhat discussed skipping qcow2 generation previously in
I9372e195913798a851c96e62eee89029e067baa1. As recent issues with PPC
testing have shown, we are not actually testing the "vm" element and
hence the bootloader path in the functional tests.
I don't think we need to test this on every element; it overlaps
somewhat with the testing done by the nodepool jobs which build full
images and boot them. I also didn't want to introduce a separate run
for this. Thus it seems valuable to at least have one element
enhanced to do this installation and conversion in our default tests
for basic sanity.
This disables qcow generation by default, as per the other change, but
allows an element to drop a file that will override the output
formats. The Xenial element is modified to produce a qcow2 using
this, and also introduces a dependency on the "vm" element so it tries
to install the bootloader.
We now exit if the .qcow2 fails to build as well.
Change-Id: I1a6acefe52f8c696c39b2d592fdc7ae32a87e6fe
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
