Re: A brief look at deprecating our JSON extensions over RFC 8259
On Mon, Feb 22, 2021 at 18:42:00 +0100, Paolo Bonzini wrote:
On 22/02/21 15:57, Markus Armbruster wrote:
> * The block layer's pseudo-protocol "json:" (which can get embedded
in
> image headers)
If it gets embedded in image headers, I don't think we'll be able to
deprecate it ever. We'd need to keep a converter for old images, at which
point it's simpler to keep the extensions.
The converter or better 'fixer' actually doesn't need to be able to
interpret the old string, just accept a new. IOW it's more of a
documentation problem, because qemu-img can already do that since it's
able to write invalid JSON without interpreting it:
$ qemu-img rebase -f qcow2 -F qcow2 -b 'json:{' -u /tmp/ble.qcow2
$ qemu-img info /tmp/ble.qcow2
image: /tmp/ble.qcow2
file format: qcow2
virtual size: 10 MiB (10485760 bytes)
disk size: 196 KiB
cluster_size: 65536
backing file: json:{
backing file format: qcow2
Format specific information:
compat: 1.1
compression type: zlib
lazy refcounts: false
refcount bits: 16
corrupt: false