On 05/26/2017 02:11 AM, Martin Kletzander wrote:
On Thu, May 25, 2017 at 10:16:26AM -0700, Peter Volpe wrote:
Hi Everyone,
We are working towards building on the virtualization management functionality in cockpit (http://cockpit-project.org/) and wanted to get some feedback on the best way to integrate with libvirt.
As a quick overview, cockpit aims to talk to existing remotable system APIs. Usually these API’s take the form of dbus, REST or executable commands. The majority of cockpit is implemented in javascript. There is no cockpit backend that knows how to change a hostname for example. The cockpit backend knows how to handle a dbus payload. The javascript running in the users browser knows how to use the systemd dbus API at org.freedesktop.hostname1 to manage the system hostname.
Right now some of the basics have been implemented by spawning commands on the system. This isn't ideal because it involves parsing / screen scraping output and doesn't support receiving events so we have to poll (ei run the command again) to keep the UI up to date.
As far as I know libvirt doesn't currently have a remoteable API. It does have a daemon that communicates with clients via a XDR RPC. (https://libvirt.org/internals/rpc.html) However from what I'm hearing the RPC is considered an internal implementation and shouldn't be used by external applications. Is that still the case? Is there any chance of getting talking the daemon directly using the XDR standard for a subset of methods blessed as part of the externally supported API?
If we standardize even the smallest part of the RPC, then it might screw us immediately. We are keeping it private just so we can enhance the APIs we already have. We don't know when we will need to change some part of it.
How does the current ssh implementation work? (https://libvirt.org/remote.html) If clients are able to talk to a remote libvirtd via ssh then there must be some sort of compatibility guarantee. Otherwise unless the versions are exactly the same clients wouldn't be able to talk to remote daemons.