`osbuild-run` sets up the build root so that programs can be run
correctly in it. It should be run for all programs, not just stages and
assemblers (even though they're the only consumers right now).
Also, conceptually, `osbuild-run` belongs to the build root. We'll
change its implementation based on the build root in a future commit.
The buildroot already sets up `/run/osbuild/api`. It makes sense to have
it manage libdir as well.
A nice side benefit of this is a simplification of the Stage and
Assembler classes, which grew quite complex and contained duplicate
code.
In BuildRoot a new mount /var pointing to temporary directory in host's
/var/tmp is created. This enables us to have temporary storage inside
the container which is not hosted on tmpfs. Thanks to that we can move
larger files out of the part of filesystem which is hosted on tmpfs to
save up memory on machines with low memory capacity.
Import modules between files using the syntax `from . import foobar`,
renaming what used to be `FooBar` to `foobar.FooBar` when moved to a
separate file.
In __init__.py only import what is meant to be public API.
Signed-off-by: Tom Gundersen <teg@jklm.no>
