[ovs-dev] proposal: ovs-vsctl commands for managing controllers/managers

Ben Pfaff blp at nicira.com
Thu Feb 3 22:48:08 UTC 2011

On Thu, Feb 03, 2011 at 12:39:29PM -0800, Andrew Evans wrote:
> On 2/3/11 12:22 PM, Ben Pfaff wrote:
> > On Thu, Feb 03, 2011 at 10:23:52AM -0800, Andrew Evans wrote:
> >> I propose we add a set of commands to add/get/delete managers that work
> >> the same way as the ones that manage controllers. I further propose we
> >> modify the existing controller commands to make it easier to add or
> >> remove one or more controllers to an existing set. Here's how this would
> >> look:
> >>
> >>   get-controllers BRIDGE
> > 
> > The existing "get-controller" already prints all of the controllers, one
> > per line.  How would "get-controllers" be different?
> Apparently it wasn't obvious that I meant to replace the existing
> controller commands. Is such a compatibility break untenable?

I didn't understand that.

I think that a compatibility break would be possible, if we did it for
an important reason, but I know that people are using this kind of
command in scripts and so I would not want to break those without good

> >>   add-controllers BRIDGE TARGET [TARGET...]
> > 
> > I don't know whether add-controllers would be useful in practice or
> > not.  Have you noticed a need for it in your own work?
> Sort of. I've been testing adding and removing multiple managers, so I
> think it's useful for add-managers/del-managers to take multiple targets
> in one shot. Ideally I'd like the controller commands to be
> syntactically identical.

We could add an add-controller command and extend del-controller to take
optional arguments without breaking compatibility.  Absent anyone else
speaking up and arguing for changing the names and the semantics, I'm
more comfortable with that.

> >>   get-managers
> >>   add-managers TARGET [TARGET...]
> >>   del-managers [--all|TARGET...]
> > 
> > I think I'd prefer to just have --all be the default if no manager is
> > named on del-managers.
> I considered that, but I think that's a bit too sharp-edged/unforgiving.

But in practice I'd expect that most of them time administrators want to
delete all the managers.  You don't think so?

> > I'd definitely like to have a "set-managers"
> > command instead of or in addition to add-managers.
> Ok. I don't see it as strictly necessary if we replace the existing
> *-controller functions, but I'm not strongly opposed to adding it either.

Again, I'd guess that more often people want to set a new manager rather
than just add a second one.  "ovs-vsctl -- del-managers --all --
add-managers <newmanager>" will work but it's a bit wordy for that.

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