plugins/driver: update driver interface to support streaming stats
client/tr: use streaming stats api
TODO:
* how to handle errors and closed channel during stats streaming
* prevent tight loop if Stats(ctx) returns an error
drivers: update drivers TaskStats RPC to handle streaming results
executor: better error handling in stats rpc
docker: better control and error handling of stats rpc
driver: allow stats to return a recoverable error
Re-export the ResourceUsage structs in drivers package to avoid drivers
directly depending on the internal client/structs package directly.
I attempted moving the structs to drivers, but that caused some import
cycles that was a bit hard to disentagle. Alternatively, I added an
alias here that's sufficient for our purposes of avoiding external
drivers depend on internal packages, while allowing us to restructure
packages in future without breaking source compatibility.
This implements the InternalPluginDriver interface in each driver, and
calls the cancellation fn for their respective eventers.
This fixes a per task goroutine leak during test suite execution.
Mock driver config uses `time.Duration` fields but we initialize them
inconsistently, as time.Duration sometimes and as duration strings other
times. Previously, `mapstructure` handles it and does the right thing.
This is no longer the case with MsgPack. I could not find a good way to
bring back old behavior without too much complexity. `MsgPack` extended
types weren't ideal here as we lose type information (e.g. int64 vs
string), and the input is a generic map and not a MsgPack serialization
of duration.
As such, I went with the simple solution of declaring the config field
as duration string, and panicing if the test doesn't pass a valid
string.
I found this to cause the smallest change in tests, but we can
alternatively force all to be int64 instead.
This PR plumbs the plugins done ctx through the base and driver plugin
clients (device already had it). Further, it adds generic handling of
gRPC stream errors.
