Spring Boot

Built on top of the Spring Framework, Spring Boot has three key things at heart:

  1. Auto Configuration: it will detect things from your dependencies, like the use of databases and configure accordingly (@EnableAutoConfiguration)
  2. Stand-alone: no need to use something like Apache Tomcat and deploy to that
  3. Opinionated: a number of things are chosen for you but can be changed

For release information it is beast to consult Home · spring-projects/spring-boot Wiki which has everything you need and is in fact a handy resource.

Actuator

It is worth adding here that the Spring Actuator, see Spring Boot Actuator: Production-ready Features, is not enabled by default. Firstly you need to add it as a dependency, and then secondly you need to consider which of the optional actuators you want. By default they are all available on JMX but only "health" and "info" and on http, with shutdown disabled completely.

You can check the Health Actuator with the following:
curl http://localhost:8080/actuator/health
This should give a very brief status indicator, in JSON, of UP or DOWN. Sometimes though, during development or debugging you need more details from the health actuator as to which sub-component is DOWN, in which case set management.endpoint.health.show-details = always, the default is never.

Kubernetes

There are dedicated probes for Kubernetes, these are documented at Production-ready Features but in summary there are liveness and readiness probes which can be enabled and then configured to be used in Kubernetes.