Re: [Qemu-devel] [Qemu-block] block/ssh:Allow blockdev-add for ssh

[Daniel P. Berrange]

On Thu, Sep 29, 2016 at 12:42:34PM +0200, Kevin Wolf wrote:
> Am 29.09.2016 um 10:07 hat Richard W.M. Jones geschrieben:
> > On Thu, Sep 29, 2016 at 01:05:48PM +0530, Ashijeet Acharya wrote:
> > > Hi all,
> > > 
> > > I was trying to convert SSH driver to support 'blockdev-add' and so
> > > far I have tried to figure out what the struct 'BlockdevOptionsSsh' in
> > > block-core.json should look like,
> > > 
> > > { 'struct': 'BlockdevOptionsSsh',
> > >   'data': { 'tcp': 'InetSocketAddress',
> > >              'path': 'str' } }
> > > 
> > > Naive question but I have to ask, Am I missing something?
> > > 
> > > As far as I know, ssh only supports 'tcp' right? So using
> > > 'InetSocketAddress' should be good enough. (like the TODO says)
> > > 
> > > I had a discussion with Kevin about this and he thinks, maybe
> > > 'SocketAddress' can be used too because the restriction comes from the
> > > qemu block driver rather than the backend. He advised me to get an
> > > opinion on this one from the maintainers of SSH.
> > 
> > I have no idea.
> 
> I searched the net a bit and it seems that SSH over Unix domain sockets
> isn't a thing. So it might actually be okay to restrict the QEMU block
> driver to TCP, too, and therefore use InetSocketAddress.
> 
> Any other opinions?

We have multiple block device drivers that all need network addresses.
I think it'd be nice if we can use the same schema for all of them,
even if some of them don't (currently) require certain options. 

eg rename 'GlusterServer' to 'BlockServer' and use it for all nework
transports. Those that don't want unix support can just reject it
at runtime, likewise those that don't need multiple-server support.

This will let mgmt apps have the same code for generating the
blockdev options for all network based transports, instead of having
to write different code for each.

Regards,
Daniel
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