We can set x-versions-location empty to remove this header in API, but
to keep consistent, we should allow x-remove-versions-location too. The
usage is post "x-remove-versions-locaion: x", just like ACL remove
headers.
Fixed: bug #1107592
Change-Id: I1271eec6401d4a0e8c1a7c2d63aeb8dfef00bf6d
Object versioning in swift is implemented by setting a flag on the container
to tell swift to version all objects in the container. The flag is the
``X-Versions-Location`` header on the container, and its value is the
container where the versions are stored.
When data is ``PUT`` into a versioned container (a container with the
versioning flag turned on), the existing data in the file is redirected to a
new object and the data in the ``PUT`` request is saved as the data for the
versioned object. The new object name (for the previous version) is
``<versions_container>/<object_name>/<timestamp>``, where the timestamp is
generated by converting the ``Last-Modified`` header value of the current
version to a unix timestamp.
A ``GET`` to a versioned object will return the current version of the object
without having to do any request redirects or metadata lookups.
Change-Id: I4fcd723145e02bbb2ec1d3ad356713f5dea43b8b