github.com/heptiolabs/healthcheck (go): Package healthcheck helps you implement Kubernetes liveness and readiness checks for your application. It supports synchronous and asynchronous (background) checks. It can optionally report each check's status as a set of Prometheus gauge metrics for cluster-wide monitoring and alerting.  It also includes a small library of generic checks for DNS, TCP, and HTTP reachability as well as Goroutine usage.
Keywords: healthcheck|kubernetes|liveness|readiness