[Engine-devel] [Users] [Feedback required][host-deploy] Fedora-19 misses tar at minimal setup

[Alon Bar-Lev]

----- Original Message -----
> From: "Alon Bar-Lev" <alonbl at redhat.com>
> To: "Juan Hernandez" <jhernand at redhat.com>
> Cc: "engine-devel" <engine-devel at ovirt.org>, "arch" <arch at ovirt.org>, "users" <users at ovirt.org>
> Sent: Sunday, July 28, 2013 1:42:58 PM
> Subject: Re: [Users] [Feedback required][host-deploy] Fedora-19 misses tar at minimal setup
> 
> 
> 
> ----- Original Message -----
> > From: "Juan Hernandez" <jhernand at redhat.com>
> > To: "Alon Bar-Lev" <alonbl at redhat.com>
> > Cc: "engine-devel" <engine-devel at ovirt.org>, "arch" <arch at ovirt.org>,
> > "users" <users at ovirt.org>
> > Sent: Sunday, July 28, 2013 12:26:56 PM
> > Subject: Re: [Users] [Feedback required][host-deploy] Fedora-19 misses tar
> > at minimal setup
> > 
> > On 07/28/2013 09:46 AM, Alon Bar-Lev wrote:
> > > Hello All,
> > >
> > > I would like to receive feedback regarding how we should cope with a
> > > state
> > > presented to use by Fedora.
> > >
> > > Fedora-19 minimal setup does not install tar utility which is required to
> > > deploy files during the host-deploy process (Hosts->Add Host).
> > >
> > > I guess because of 2.8M in size (including translations) -- a standard
> > > commonly used utility was removed.
> > >
> > > There are two alternatives :
> > >
> > > 1. Instruct users who are using minimal installations to manually install
> > > tar utility just like they configure repository, dns, etc..
> > >
> > > Benefit: simplicity.
> > > Benefit: use standard tools.
> > > Benefit: lower payload to transmit.
> > > Drawback: require tar at destination machine.
> > >
> > > 2. Do not use tar but self extracting python script, a patch is ready[1].
> > >
> > > Benefit: ability to deploy environment in which tar is missing.
> > > Drawback: non standard tool at destination machine.
> > > Drawback: complexity within our code.
> > >
> > > [[[
> > > There was 3rd alternative, using python tar module to deploy tar.
> > > However, there is a bug in that module when processing last block if
> > > empty.
> > > This is edge condition but happened to at least one of the users and I
> > > could
> > > reproduce it.
> > > ]]]
> > >
> > > Regards,
> > > Alon Bar-Lev
> > 
> > Consider using cpio instead of tar. It is required to build initrd, so
> > available in any installation. It is also supported by the library
> > currently used in the engine to build the tar archive.
> 
> Thanks Juan, it is good idea.
> 
> I did not thought of using cpio, as I remembered that cpio has no embedded
> eof (a.cpio+b.cpio=cpio), but now I experiments and see that I was mistaken.
> 
> Will try to establish a working solution.

Done[1].
Thanks!

host-deploy: use cpio instead of tar for bundle transfer


for some reason fedora-18/19 got tar out of base system, so we are
forced to find some solution, although manual configuration is required
anyway (repository, networking etc...).

there was attempt to use python tar module, however this module has a
bug when last block is empty, so it is not suitable for usage.

cpio is alternative for fedora, however it is rightfully missing from
other distributions as it is much less used. as we do not support hosts
using different distributions, we are ok now.

in future, we can use python self extract script, work already performed
at: I1e5ddab9ae87979da7d7296c4f3c7ef08e21e903 at the price of
complexity.

Change-Id: I1386e7d688a9ec7e28519fb407478fd17cbab4ca
Signed-off-by: Alon Bar-Lev <alonbl at redhat.com>

[1] http://gerrit.ovirt.org/#/c/17396/