* Move tracing exporter registration
This doesn't belong in the library and should be configured by the
consumer of the opencensus package.
* Rename `vkublet` package to `node`
`vkubelet` does not convey any information to the consumers of the
package.
Really it would be nice to move this package to the root of the repo,
but then you wind up with... interesting... import semantics due to the
repo name... and after thinking about it some, a subpackage is really
not so bad as long as it has a name that convey's some information.
`node` was chosen since this package deals with all the semantics of
operating a node in Kubernetes.
This changes the tracing package to accept an error on SetStatus, which
is really what we always want anyway.
This also decouples the trace package from opencensus.
This cleans up the CLI code significantly.
Also makes some of this re-usable for providers who want to do so.
This also removes the main.go from the top of the tree of the repro,
instead moving it into cmd/virtual-kubelet.
This allows us to better utilize the package namespace (and e.g. mv the
`vkubelet` package to the top of the tree).
* Define and use an interface for logging.
This allows alternative implementations to use whatever logging package
they want.
Currently the interface just mimicks what logrus already implements,
with minor modifications to not rely on logrus itself. I think the
interface is pretty solid in terms of logging implementations being able
to do what they need to.
* Make tracing interface to coalesce logging/tracing
Allows us to share data between the tracer and the logger so we can
simplify log/trace handling wher we generally want data to go both
places.
