We want to retrieve that actual raw data for a specific virtual machine image that the Glance server knows about.
We have queried the Glance server for a list of public images and the data returned includes the `uri` field for each available image. This `uri` field value contains the exact location needed to get the metadata for a specific image.
Continuing the example from above, in order to get metadata
about the first public image returned, we can issue a
HEAD request to the Glance server for the
image's URI.
We issue a GET request to
http://glance.example.com/images/1 to
retrieve metadata for that image as well as the image itself
encoded into the response body.
The metadata is returned as a set of HTTP headers that
begin with the prefix x-image-meta-. The
following shows an example of the HTTP headers returned from the
above GET request:
x-image-meta-name Ubuntu 10.04 Plain 5GB x-image-meta-disk-format vhd x-image-meta-container-format ovf x-image-meta-size 5368709120 x-image-meta-checksum c2e5db72bd7fd153f53ede5da5a06de3 x-image-meta-location swift://account:key/container/image.tar.gz.0 x-image-meta-created_at 2010-02-03 09:34:01 x-image-meta-updated_at 2010-02-03 09:34:01 x-image-meta-deleted_at x-image-meta-status available x-image-meta-is-public true x-image-meta-owner null x-image-meta-property-distro Ubuntu 10.04 LTS
All timestamps returned are in UTC The `x-image-meta-updated_at` timestamp is the timestamp when an image's metadata was last updated, not its image data, as all image data is immutable once stored in Glance There may be multiple headers that begin with the prefix `x-image-meta-property-`. These headers are free-form key/value pairs that have been saved with the image metadata. The key is the string after `x-image-meta-property-` and the value is the value of the header The response's `Content-Length` header shall be equal to the value of the `x-image-meta-size` header The response's `ETag` header will always be equal to the `x-image-meta-checksum` value The response's `x-image-meta-is-public` value is a boolean indicating whether the image is publicly available The response's `x-image-meta-owner` value is a string which may either be null or which will indicate the owner of the image The image data itself will be the body of the HTTP response returned from the request, which will have content-type of `application/octet-stream`.
