Re: [PATCH] block/rbd: Add support for ceph namespaces

[Eric Blake <eblake@redhat.com>]

On 12/19/19 7:34 AM, Florian Florensa wrote:
> Starting from ceph Nautilus, RBD has support for namespaces, allowing
> for finer grain ACLs on images inside a pool, and tenant isolation.
> 
> In the rbd cli tool documentation, the new image-spec and snap-spec are :
>   - [pool-name/[namespace-name/]]image-name
>   - [pool-name/[namespace-name/]]image-name@snap-name
> 
> When using an non namespace's enabled qemu, it complains about not
> finding the image called namespace-name/image-name, thus we only need to
> parse the image once again to find if there is a '/' in its name, and if
> there is, use what is before it as the name of the namespace to later
> pass it to rados_ioctx_set_namespace.
> rados_ioctx_set_namespace if called with en empty string or a null
> pointer as the namespace parameters pretty much does nothing, as it then
> defaults to the default namespace.
> 
> The namespace is extracted inside qemu_rbd_parse_filename, stored in the
> qdict, and used in qemu_rbd_connect to make it work with both qemu-img,
> and qemu itself.
> 
> Signed-off-by: Florian Florensa <fflorensa@online.net>
> ---

> +++ b/qapi/block-core.json
> @@ -3657,6 +3657,8 @@
>   #
>   # @pool:               Ceph pool name.
>   #
> +# @nspace:             Rados namespace name in the Ceph pool.
> +#

Needs a '(since 5.0)' tag.

>   # @image:              Image name in the Ceph pool.
>   #
>   # @conf:               path to Ceph configuration file.  Values
> @@ -3683,6 +3685,7 @@
>   ##
>   { 'struct': 'BlockdevOptionsRbd',
>     'data': { 'pool': 'str',
> +            'nspace': 'str',

This makes a new argument mandatory, which breaks expectations of older 
clients that failed to provide it. You probably want to make it 
'*nspace', and have a sane default when the argument is not present.

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org