Pass span context in ociwclayer

[helsaawy]

Bypass function in base package (.\layers.go) and use layer functions
defined in .\internal\wclayer, since those allow propagating (span)
context.

Signed-off-by: Hamza El-Saawy [email protected]

[jterry75]

Do we know why ociwclayer was using hcsshim Docker api's in the first place? Do we risk breaking anything here?

[helsaawy]

Do we know why ociwclayer was using hcsshim Docker api's in the first place? Do we risk breaking anything here?

I dont think so. ociwclayer seems to only be passing an empty hcsshim.DriverInfo{} struct, so the filepath.Join(info.HomeDir, id) turns into a filepath.Join("", id).

[jterry75]

Yea thats a v1 ISM. @TBBle - PTAL given your recent work on containerd that consumed this.

[TBBle]

ociwclayer was using the public APIs because I unified it over from existing code in other repos (containerd and docker contained variations of this package's code), which only had access to the public APIs, and because all the other APIs used by containerd and Docker still take this empty DriverInfo.

Nothing should break from this change, since the callers are already passing a context into the public pkg/ociwclayer APIs.

I kind of wanted to make internal/wclayer (or some of its APIs) public too and just get rid of DriverInfo in non-legacy callers, but I expected to land a fully-tested Snapshotter in containerd first so there was a known-good state to iterate from, and that got jammed up on the Base Layer Manipulation PR. I was hoping to move over to the RS5 APIs (computestorage) since both Docker and containerd support RS5 onwards only, so perhaps exposing more of internal/wclayer isn't valuable anyway.