[Libguestfs] how do i use a blob appliance the compiling from source

[Richard W.M. Jones]

On Wed, Jan 27, 2010 at 12:14:23AM +0200, Piavlo wrote:
> Since I've never succeeded to compile libguestfs from source on
> Gentoosince the build process of the appliance based on debootstrap fails,
> I'm wondering how can I tell the compilation process to use a
> precompiled blob appliance?

OK so I guess you've read this:

http://libguestfs.org/FAQ.html#distros

You want to take option (3).

You will need a Fedora virtual machine in order to create the
appliance.  Install (eg) Fedora 12 [Note 1] or Fedora Rawhide in a
virtual machine on your Gentoo system, and inside the Fedora virtual
machine install libguestfs:

 # yum install '*guestf*'

You can then use libguestfs itself to create the appliance:

 $ libguestfs-supermin-helper /usr/lib64/guestfs /tmp/kernel /tmp/initrd
[Note 2]

/tmp/kernel will be a symbolic link to the kernel which you should
copy out.  /tmp/initrd will be the appliance (quite a large file:
usually around 100 MB).

Those two files are the precompiled "blob" appliance as you call it.

You can compile the rest of libguestfs, but first copy the 'kernel'
file into 'appliance/vmlinuz.fedora-12.x86_64.img' and the 'initrd'
file into 'appliance/initramfs.fedora-12.x86_64.img', before doing the
rest of the build.

I'm hoping that the build will notice that these files have already
been created and not try to rebuild them, but I haven't actually tried
this.  You might want to read the Makefile.am's and ping me on our IRC
channel for a bit more help with this.

> Also can I use non fedora & debian but use some minimal gentoo based
> appliance I have?

Probably not.  You cannot use any random appliance, since it needs to
have specific software installed, and a specific /init script etc.

However you can use the Fedora or Debian appliance _on_ a Gentoo host
no problem (ie. option (3)).

It should also be possible to (e)build a Gentoo appliance, which would
definitely be the best option here!

Rich.

Notes
-----

[1] http://fedoraproject.org/en/get-fedora

[2] In libguestfs 1.0.82 we will change the command line arguments to
this command slightly, see my post earlier today on this list.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
New in Fedora 11: Fedora Windows cross-compiler. Compile Windows
programs, test, and build Windows installers. Over 70 libraries supprt'd
http://fedoraproject.org/wiki/MinGW http://www.annexia.org/fedora_mingw