This adds trace context propagation over the grpc/ttrpc calls to a shim.
It also adds the otlp plugin to the runc shim so that it will send
traces to the configured tracer (which is inherited from containerd's
config).
It doesn't look like this is adding any real overhead to the runc shim's
memory usage, however it does add 2MB to the binary size.
As such this is gated by a build tag `shim_tracing`
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
These are standard environment variables described by the otel spec in
https://opentelemetry.io/docs/specs/otel/configuration/sdk-environment-variables/.
The old config options are removed
Also since otel will by default try to connect to https://localhost:4318
if no endpoint is set, this will also just disable the otlp plugin when
there is no endpoint so we don't have otel continuously trying to
connect to the default endpoint, littering the logs with connection
failure messages and collecting traces that won't go anywhere.
Signed-off-by: Brian Goff <cpuguy83@gmail.com>
