The CSI HTTP API has to transform the CSI volume to redact secrets,
remove the claims fields, and to consolidate the allocation stubs into
a single slice of alloc stubs. This was done manually in #8590 but
this is a large amount of code and has proven both very bug prone
(see #8659, #8666, #8699, #8735, and #12150) and requires updating
lots of code every time we add a field to volumes or plugins.
In #10202 we introduce encoding improvements for the `Node` struct
that allow a more minimal transformation. Apply this same approach to
serializing `structs.CSIVolume` to API responses.
Also, the original reasoning behind #8590 for plugins no longer holds
because the counts are now denormalized within the state store, so we
can simply remove this transformation entirely.
The HTTP test to create CSI volumes depends on having a controller plugin to
talk to, but the test was using a node-only plugin, which allows it to
silently ignore the missing controller.
