Add a field "enable_annotations" to the runtime configuration that can
be used to whitelist annotations using a list of regular expressions,
which are used to match any part of the base annotation name, i.e. the
part after "io.katacontainers.config.hypervisor."
For example, the following configuraiton will match "virtio_fs_daemon",
"initrd" and "jailer_path", but not "path" nor "firmware":
enable_annotations = [ "virtio.*", "initrd", "_path" ]
The default is an empty list of enabled annotations, which disables
annotations entirely.
If an anontation is rejected, the message is something like:
annotation io.katacontainers.config.hypervisor.virtio_fs_daemon is not enabled
Fixes: #901
Suggested-by: Peng Tao <tao.peng@linux.alibaba.com>
Signed-off-by: Christophe de Dinechin <dinechin@redhat.com>