Re: [Libguestfs] [PATCH] appliance: reorder the steps to search for appliance
On Tue, Apr 25, 2017 at 06:13:37PM +0300, Pavel Butsykin wrote:
On 25.04.2017 16:04, Richard W.M. Jones wrote:
>Can you see what:
>
> guestfish get-path
/usr/lib64/guestfs
>prints? Are you setting LIBGUESTFS_PATH at all?
>
No.
# ls /usr/lib64/guestfs
initrd kernel README.fixed root supermin.d
libguestfs by default uses a single path to search fixed appliance and
supermin.d. It seemed to me that the presence of options "--disable
appliance --disable-daemon" must exclude the use of
build_supermin_appliance.
But libguestfs in any case trying to find supermin.d.
OK, I see - what's actually happening is that you've got a path which
is both a fixed appliance and a supermin appliance (although maybe it
only appears to be a supermin appliance -- libguestfs just looks for
the "supermin.d" entry and decides it's a supermin appliance).
Maybe it's not
quite right to make such decisions based on the contents of the
directory.
Yes that's right, but see below.
Also, I still don't understand what the priority of the search
appliances was supposed to actually use. Because in the documentation
the first step is to search for fixed appliance, but is actually
supermin.d(for building appliance).
There's not a priority in this situation. It wasn't intended that two
different appliances would be on the exact same path.
Some possible solutions:
(1) Make the check in lib/appliance.c: contains_supermin_appliance
more robust.
It could perhaps be changed so that it checks that at least
"base.tar.gz" and "packages" are found within the supermin.d
directory. Those are the minimum two files that must be in a supermin
appliance (see supermin(8)).
(2) If the fixed appliance was located somewhere else, you could do:
LIBGUESTFS_PATH=/path/to/somewhere/else:/usr/lib64/guestfs
export LIBGUESTFS_PATH
and then it would look for the fixed appliance in
/path/to/somewhere/else and use it. If the fixed appliance exists
there, then it would never check /usr/lib64/guestfs.
(3) You could also compile a different path into libguestfs.
Unfortunately there's no way to specify it at configure time, but see
GUESTFS_DEFAULT_PATH in the sources.
(4) Delete /usr/lib64/guestfs/supermin.d
Rich.
--
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