Leveled logging

[andrewrynhard]

Using either the standard library, or something like logrus, we should provide more robust logging.

[bradbeam]

Need to review the various log packages to weigh them

• logrus ( ability to inject metadata with fields, native-ish syslog output )
• zap ( fast )
• glog / klog ( k8s uses, semi proven )
• others(?)

Need to figure out the appropriate log structure, ex.

• If using logrus, do we want to have a standard set of fields we apply to all messages?
• Do we go super verbose on debug level messages to help with tracing?

Need to figure out log pattern --
Do we want to always log super verbose level, but filter/query via osctl? ( #wayfuturestate )

Once we get those pieces together, we should be able to just take on a package or so at a time and get this implemented

[smira]

with zap, there's some ground work done to let it flow to fluentd for aggregation: https://github.com/smira/zap-msgpack-encoder

[andrewrynhard]

Closing in favor of internal epic.