[lxc-devel] [PATCH v3] Add Oracle Linux template

[Serge Hallyn]

Quoting Dwight Engen (dwight.engen at oracle.com):
> On Fri, 5 Oct 2012 16:52:27 -0500
> Serge Hallyn <serge.hallyn at canonical.com> wrote:
> 
> > Quoting Dwight Engen (dwight.engen at oracle.com):
> > > 
> > > This is a new template to create containers based on Oracle Linux.
> > > A version such as 5.8, 6.3, or 6.latest can be specified with -R in
> > > which case a rootfs will be created from rpms downloaded from the
> > > Oracle public-yum repo. Alternatively the path to an existing
> > > rootfs of Oracle 5 or 6 may be given to the template with the -t
> > > option.
> > > 
> > > The architecture of the downloaded rpms installed in the container
> > > can be specified with the -a template option.
> > > 
> > > Signed-off-by: Dwight Engen <dwight.engen at oracle.com>
> > 
> > Thanks, Dwight - I'd actually pushed this to my staging branch and a
> > bzr branch, but then I noticed one thing:
> > 
> > > ---
> > >  configure.ac            |    1 +
> > >  templates/Makefile.am   |    1 +
> > >  templates/lxc-oracle.in |  496
> > > +++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed,
> > > 498 insertions(+), 0 deletions(-) create mode 100644
> > > templates/lxc-oracle.in
> > > 
> > > diff --git a/configure.ac b/configure.ac
> > > index 4bbfd9b..d0535f7 100644
> > > --- a/configure.ac
> > > +++ b/configure.ac
> > > @@ -197,6 +197,7 @@ AC_CONFIG_FILES([
> > >  	templates/lxc-opensuse
> > >  	templates/lxc-busybox
> > >  	templates/lxc-fedora
> > > +	templates/lxc-oracle
> > >  	templates/lxc-altlinux
> > >  	templates/lxc-sshd
> > >  	templates/lxc-archlinux
> > > diff --git a/templates/Makefile.am b/templates/Makefile.am
> > > index d6b3892..523498d 100644
> > > --- a/templates/Makefile.am
> > > +++ b/templates/Makefile.am
> > > @@ -7,6 +7,7 @@ templates_SCRIPTS = \
> > >  	lxc-ubuntu-cloud \
> > >  	lxc-opensuse \
> > >  	lxc-fedora \
> > > +	lxc-oracle \
> > >  	lxc-altlinux \
> > >  	lxc-busybox \
> > >  	lxc-sshd \
> > > diff --git a/templates/lxc-oracle.in b/templates/lxc-oracle.in
> > > new file mode 100644
> > > index 0000000..e13f13b
> > > --- /dev/null
> > > +++ b/templates/lxc-oracle.in
> > > @@ -0,0 +1,496 @@
> > > +#!/bin/bash
> > > +#
> > > +# Template script for generating Oracle Enterprise Linux container
> > > for LXC +# based on lxc-fedora, lxc-ubuntu
> > > +#
> > > +# Copyright © 2011 Wim Coekaerts <wim.coekaerts at oracle.com>
> > > +# Copyright © 2012 Dwight Engen <dwight.engen at oracle.com>
> > > +#
> > > +# Modified for Oracle Linux 5
> > > +# Wim Coekaerts <wim.coekaerts at oracle.com>
> > > +#
> > > +# Modified for Oracle Linux 6, combined OL5,6 into one template
> > > script +# Dwight Engen <dwight.engen at oracle.com>
> > > +#
> > > +# This library is free software; you can redistribute it and/or
> > > +# modify it under the terms of the GNU Lesser General Public
> > > +# License as published by the Free Software Foundation; either
> > > +# version 2.1 of the License, or (at your option) any later
> > > version. +#
> > > +# This library is distributed in the hope that it will be useful,
> > > +# but WITHOUT ANY WARRANTY; without even the implied warranty of
> > > +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
> > > +# Lesser General Public License for more details.
> > > +#
> > > +# You should have received a copy of the GNU Lesser General Public
> > > +# License along with this library; if not, write to the Free
> > > Software +# Foundation, Inc., 59 Temple Place, Suite 330, Boston,
> > > MA 02111-1307 USA +#
> > > +
> > > +# use virbr0 that is setup by default by libvirtd
> > > +lxc_network_type=veth
> > > +lxc_network_link=virbr0
> > 
> > This should be taken from a config file (at least if provided), not
> > overriden in the template.  So for instance, I was (implicitly) using
> > lxc-create -t oracle -f /etc/lxc/lxc.conf -n o1
> > where lxc.conf is:
> > 
> > lxc.network.type=veth
> > lxc.network.link=lxcbr0
> > lxc.network.flags=up
> > 
> > but the oracle container was set to lxc.network.link=virbr0.  Since I
> > didn't have libvirt installed, the resulting container fails to start.
> > When I switch the link over, it starts beautifully.
> > 
> > I'm not sure how you'll want to do it - just not 
> > 
> >     rm -f $cfg_dir/config
> > 
> > and then only add a network segment if one hasn't already been
> > specified?
> > 
> > For now I've pushed your patch unchanged onto github.com/hallyn/lxc
> > branch staging.oct5.1 (and onto
> > lp:~serge-hallyn/ubuntu/quantal/lxc/lxc-oracle), but that should be
> > fixed before being merged into the github.com/lxc/lxc staging branch.
> > 
> > -serge
> 
> My testing was on OL6.3, so I hadn't run into these things. So I tried
> this in a Ubuntu VM and I see the problems you are getting at, as well
> as a few more :(
> 
> Hmm, yes the veth thing is not good. So I noticed that Ubuntu has
> a /etc/lxc/lxc.conf file which dpkg -L does say comes from lxc, but I
> don't see where that comes from in the lxc source? For an rpm based
> system like OL it seems like I should add an equivalent .conf file and
> have the .spec pull it in? Also the part of lxc-create that Ubuntu has

Ubuntu by default creates a lxcbr0 bridge (NATed to the default nic).
So /etc/lxc/lxc.conf is ubuntu-specific because how to set such a
bridge up at boot is quite distro-specific.

Perhaps we should look into doing this all through augeas.

> to copy /etc/lxc/lxc.conf as the skel to start with isn't in the git
> sources, so just adding the file in /etc wouldn't suffice. The
> alternative is like you said to detect if a network isn't given, but
> that could get messy (what if the config from /etc has other stuff that
> conflicts?). Seems like we should all do it the same way, and the idea
> is that /etc is the place to specify *host* system wide, but distro
> specific things and the template adds onto that.
> 
> Another problem with this template when Ubuntu is the host is that
> Ubuntu's native rpm builds the rpm database into
> $container_rootfs/root/.rpmdb so when you boot into the container rpm
> -qa shows nothing because there is no database in /var/lib/rpm. Should I
> just try to detect if the host is Ubuntu and move the db files
> from .rpmdb to /var/lib/rpm? Are other (non-rpm-native) platforms going
> to have this problem as well, and do I need to handle them too?

Can you simply always pass '--dpath=/var/lib/rpm'?

My guess is that most non-rpm-native systems will try to avoid using
/var/lib/rpm by default, but that's purely a guess, and I'm not sure
if that should be deemed a bug in the debian package (especially the
fact that it isn't mentioned in the debian/README.Debian file)

> Also the db4 tool names aren't the same as on RHEL/OL if a database
> downgrade will be required (and I need to detect that case better,
> right now its going by the hosts /etc/oracle-release which obviously
> won't work if your host isn't Oracle, I'll probably switch to use the
> file command to test the hash version of the db). I guess I can check
> for a bunch of "alternate" tool names, any better ideas?

Hopefully someone more knowledgeable than I can pipe in...

thanks,
-serge