[Hawkular-dev] some new hawkular openshift agent stuff

[John Mazzitelli]

FYI: some new things went into HOSA (that's the Hawkular OpenShift Agent for the uninitiated).

1. The agent now emits its own metrics and can monitor itself. Right now it just emits some basic "go" metrics like memory usage, CPU usage, etc along with one agent-specific one - a counter that counts the number of data points it has collected in its lifetime. We'll add more metrics as we figure out the things people want to see, but we have the infrastructure in place now.

2. The agent is deployed as a daemonset. This means as new nodes are brought online, an agent will go along with it (or so I'm told :)

3. The agent has changed the way it discovers what to monitor - it no longer looks at annotations on pods to determine where the configmaps are for those pods. Instead, it looks up volume declarations to see if there is an agent configmap defined. This was done to be ready for the future when new security constraints will be introduced in OpenShift which would have broken our annotation approach. This approach using volumes should not hit that issue.

NOTE: If you are building the latest agent from master, we added some dependencies so you have to update your dependencies via Glide by using the "make update-deps" target prior to building from source.