[libvirt] [RFC] Design executing commands from within domains

[Daniel P. Berrange]

On Wed, Aug 10, 2016 at 02:32:47PM +0800, Chen Hanxiao wrote:
> 在 2016-08-09 19:03:32，"Andrea Bolognani" <abologna at redhat.com> 写道：
> >On Mon, 2016-08-08 at 16:19 +0100, Daniel P. Berrange wrote:
> >> IOW, I don't think we should ever expose the qemu guest agent exec command
> >> via libvirt APIs.
> >> 
> >> If people want a general purpose exec facility, they can trivially write
> >> a much better exec feature via a separate virtio-serial channel (or via
> >> the new virtio-vsock), and stil access that over libvirt by using the
> >> virDomainOpenChannel to connect to the host side of the channel if needed
> >
> >Personally, I feel like most of this is way out of scope for
> >libvirt.
> >
> >If you want to monitor the disk / memory usage of your guest,
> >just run the Nagios agent or whatever in it; if you want to
> >run random commands, just use ssh.
> 
> One of the use cases for guest agent exec is that
> when network service is abnormal,
> we could restart it in VMs rather than vnc/spice :)

So just make your monitoring app be able to run over virtio-serial or
virtio-vsock, to it can avoid relying on network. These are explicitly
designed to allow multiple services, so we don't need to shove everything
via the QEMU guest agent.


Regards,
Daniel
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