Re: [Qemu-block] [Qemu-devel] [PATCH for-2.8] iotests: Do not rely on unavailable domains in 162

[Max Reitz]

On 2016-08-23 at 07:44, Sascha Silbe wrote:
> Dear Max,
>
> Max Reitz <address@hidden> writes:
>
> [tests/qemu-iotests/162]
> [...]
> > +# (We need to set up a server here, because the error message for "Connection
> > +#  refused" does not contain the destination port)
> > +$QEMU_NBD -p 42424 -f raw null-co:// &
> > +sleep 0.5
> > +$QEMU_IMG info 'json:{"driver": "nbd", "host": "localhost", "port": 42424}' \
> > +    | grep '^image'
>
> Using a fixed port number means multiple users won't be able to run this
> in parallel. That it's only open for a short time actually makes the
> issue a bit worse as it's hard to understand just why the test failed
> intermittently.
>
> Is there a way to have qemu-nbd use a random port and print the port
> number?

Good idea. We can just let the script generate a random port; 
$(($RANDOM+32768)) should do the trick.

Max