I've fixed that using the same ceph-auth-key for both cinder and nova ceph-user, that way, when nova tries to attach a volume using cinder-ceph-user and nova-libvirt-secret it will match and work.
I've fixed that using the same ceph-auth-key for both cinder and nova ceph-user, that way, when nova tries to attach a volume using cinder-ceph-user and nova-libvirt-secret it will match and work.