[Libguestfs] [PATCH] add enable_appliance flag to specify the appliance build

[Richard W.M. Jones]

On Fri, Apr 28, 2017 at 05:03:58PM +0300, Pavel Butsykin wrote:
> On 27.04.2017 18:28, Richard W.M. Jones wrote:
> >
> >On Thu, Apr 27, 2017 at 03:55:10PM +0300, Pavel Butsykin wrote:
> >>The flag determines the behavior of working with the appliance, and specifically
> >>the choice to use the build supermin appliance or the fixed appliance. If the
> >>flag is false then the libguestfs will only use the fixed appliance, otherwise
> >>the build supermin appliance.
> >>
> >>This patch is aimed at solving the problem with undefined behavior when
> >>searching for the appliance. The libguestfs configured with --enable-appliance
> >>will only use the build supermin appliance, with --disable-appliance only use
> >>the fixed appliance.
> >>
> >
> >It has to be said I like this approach even less :-/
> >
> 
> Any arguments? What exactly is wrong?

Specifically it exposes a whole new API which just serves to adjust
some internal issue in libguestfs (which as I said in the other reply
is really a bug in libguestfs).  Adding new APIs has a high bar
because we have to support them forever.

I really think the solution here is to fix the path search so it
works like you'd expect a path search to work, ie:

  LIBGUESTFS_PATH=/a:/b:/c

means look in /a for any appliance, then look in /b, then look in /c.
(Whereas currently it means something like "go round and round in
circles looking for different sorts of appliance".)

Then change the distro so it doesn't install two appliances into a
single location, which only ever worked by random chance (if indeed it
ever did work).

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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