On Fri, Sep 14, 2007 at 03:26:40AM +0100, Daniel P. Berrange wrote:
> All the really trendy network services these days broadcast their presence
> on the LAN using mDNS. In Linux world this means becoming an Avahi client
> and registering our services. virt-manager is also able to become an Avahi
> client and browser for services. So you'll be able to let the user just
> pick a host straight off a list instead of typing in hostname.
+1 on the principle, allows to break the bootstrap problem and way better
from an UI perspective (as long as you don't end up with a 200 host lost to
pick from.
> The attached patch does two things:
>
> - Extends our event loop implementation so it can modify the event mask
> associated with an FD, and the timeout associated with a timer. While
> you could simulate this with an add & remove, this has the possibility
> of failure (from malloc). Merely updating an existing event can be done
> without failure. Avahi needs this ability for its event loop integration
>
> - Added qemu/mdns.c file to actually provide the service information. This
> has two parts. The first section of code is taken straight from one of
> the Avahi example programs. The second section is a implementaiton of the
> Avahi event loop contract in terms of our event API - it works very nicely
> which says good things about design of our event loop
>
> Some things...
>
> - I arbitrarily picked a service type of '_libvirtd._tcp'. The docs on
> picking service types seem non-existant on Avahi website, but it seems
> to be common to use service name from /etc/services and protocol both
> prefixed with _.
>
> - I advertise two subtypes, of '_xen.libvirtd._tcp' and '_qemu.libvirtd._tcp'
> What I actually want todo is to be able to probe the libvirt local drivers
> to auto-discover what virtualization platforms are available. A sort of
> lightweight virConnectOpen which merely returns TRUE/FALSE and doesn't
> actually allocate a virConnectPtr object. Need to extend the internal
> driver API for this.
>
> - I want to advertise whether the server is configured with TLS certs or
> not, so remote clients can automatically choose to use SSH urls with
> the remote driver if neccessary.
>
> - Let the admin turn advertisement on/off in the config file because some
> people may not like it on their LAN.
>
> If you fancy trying it, avahi-browse --all from another host on the LAN
> should show the service being advertised. The advertisements do not cross
> LAN routers by default.
Can't review the patch right now, will try over the week-end,
thanks !
Daniel
--
Red Hat Virtualization group http://redhat.com/virtualization/
Daniel Veillard | virtualization library http://libvirt.org/
veillard@xxxxxxxxxx | libxml GNOME XML XSLT toolkit http://xmlsoft.org/
http://veillard.com/ | Rpmfind RPM search engine http://rpmfind.net/
--
Libvir-list mailing list
Libvir-list@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/libvir-list