We must avoid depending on the host's state in any way. This achieves
isolation in the following ways:
- rather than the default config file /dev/null is used
- rather than sharing the host persistent state dir a temporary one
is used and thrown away for each call
- the module_platform_id is set explicitly per supported distro, rather
than taken from /etc/os-release.
Optionally, the cache directory can be configured, as we may want to keep
this separate from the host, if for no other reason than accounting.
However, the cache appears to be well-behaved, so we can keep sharing
it between calls (or even with the host). This speeds up things
considerably, so this is definitely what we want.
Signed-off-by: Tom Gundersen <teg@jklm.no>
cdd1912e78