Metrics

[ChristopherDavenport]

People want metrics on their pools. We should expose and approach that people can expose their metrics over the state of their pools. Both checked out and checked in keys. And how many are in each state.

• We need an abstraction that can be leveraged independently by different implementors.
• We need a concrete implementation (probably epimetheus) consuming this and able to create concrete metrics so other implementors have prior art.