disk.device.*.rate measurements are lacking in pipeline

[Wenyan Zhang]

Disk.device.*.rate measurements are lacking by libvirt hypervisor, the same as disk.read.bytes.rate measurement.
But the different is we could get the disk.read.bytes.rate measurement from pipeline.
We shoule also add configurations of disk.device.*.rate measurements into pipeline.yaml. And I have tested the configutation is effective.

This bug is related to the bug:
https://bugs.launchpad.net/ceilometer/+bug/1393328

- name: disk_device_sink
      transformers:
          - name: "rate_of_change"
            parameters:
                source:
                    map_from:
                        name: "disk.device\\.(read|write)\\.(bytes|requests)"
                        unit: "(B|request)"
                target:
                    map_to:
                        name: "disk.device.\\1.\\2.rate"
                        unit: "\\1/s"
                    type: "gauge"
      publishers:
          - notifier://

[ZhiQiang Fan (aji-zqfan)]

https://github.com/openstack/ceilometer/commit/acfcb911869adf3d4b6b5995cc9f2d29083308eb

[Wenyan Zhang (zhang-wenyan3)]

Thanks for your comment. This change would solve the problem.