Chapter 20. Identifying virtual devices with tags

To tag virtual devices, use the tag parameters, --block-device and --nic, when creating instances.

Here is an example:

$ nova boot test-vm --flavor m1.tiny --image cirros \
--nic net-id=55411ca3-83dd-4036-9158-bf4a6b8fb5ce,tag=nfv1 \
--block-device id=b8c9bef7-aa1d-4bf4-a14d-17674b370e13,bus=virtio,tag=database-server NFVappServer

The resulting tags are added to the existing instance metadata and are available through both the metadata API, and on the configuration drive.

In this example, the following devices section populates the metadata:

Sample contents of the meta_data.json file:

    {
  "devices": [
    {
        "type": "nic",
        "bus": "pci",
        "address": "0030:00:02.0",
        "mac": "aa:00:00:00:01",
        "tags": ["nfv1"]
    },
    {
        "type": "disk",
        "bus": "pci",
        "address": "0030:00:07.0",
        "serial": "disk-vol-227",
        "tags": ["database-server"]
    }
  ]
}

The device tag metadata is available using GET /openstack/latest/meta_data.json from the metadata API.

If the configuration drive is enabled, and mounted under /configdrive in the instance operating system, the metadata is also present in /configdrive/openstack/latest/meta_data.json.