qemu-nbd: allow specifying image as a set of options args

Currently qemu-nbd allows an image filename to be passed on the
command line, but unless using the JSON format, it does not have
a way to set any options except the format eg

   qemu-nbd https://127.0.0.1/images/centos7.iso
   qemu-nbd /home/berrange/demo.qcow2

This adds a --image-opts arg that indicates that the positional
filename should be interpreted as a full option string, not
just a filename.

   qemu-nbd --image-opts driver=https,url=https://127.0.0.1/images,sslverify=off
   qemu-nbd --image-opts driver=file,filename=/home/berrange/demo.qcow2

This flag is mutually exclusive with the '-f' flag.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/qemu-nbd.texi b/qemu-nbd.texi
index 227a73ca36..9f23343450 100644
--- a/qemu-nbd.texi
+++ b/qemu-nbd.texi
@@ -13,7 +13,8 @@ Export a QEMU disk image using the NBD protocol.
 @c man end
 
 @c man begin OPTIONS
-@var{filename} is a disk image filename.
+@var{filename} is a disk image filename, or a set of block
+driver options if @var{--image-opts} is specified.
 
 @var{dev} is an NBD device.
 
@@ -33,6 +34,10 @@ The offset into the image
 The interface to bind to (default @samp{0.0.0.0})
 @item -k, --socket=@var{path}
 Use a unix socket with path @var{path}
+@item --image-opts
+Treat @var{filename} as a set of image options, instead of a plain
+filename. If this flag is specified, the @var{-f} flag should
+not be used, instead the '@code{format=}' option should be set.
 @item -f, --format=@var{fmt}
 Force the use of the block driver for format @var{fmt} instead of
 auto-detecting