Always return a containerd shutdown wait function after successful
initialization, including when using an externally managed system containerd,
where the function is a no-op.
Use the returned function during the normal shutdown sequence, after the API
server has stopped, so managed and embedded containerd instances have finished
shutting down before tracing is torn down. Keep a deferred context cancellation
as a safeguard for early returns.
Bound OpenTelemetry shutdown to avoid blocking daemon shutdown indefinitely,
and defer returning ServeAPI errors until containerd and tracing shutdown have
completed.
Also report failures while waiting for containerd to stop instead of silently
discarding them.
Signed-off-by: Sebastiaan van Stijn <github@gone.nl>
Sebastiaan van Stijn
fb21f97c41