Add HealthIndicator implementation for ArangoDB for readiness checks

[oliverlockwood]

We have recently upgraded our microservices platform to use Spring-Boot 2.3 and are making use of the new functionality around liveness & readiness health checks. In general it seems to be working well 👍

A number of our microservices use ArangoDB as a backing store. I would like these microservices to include Arango availability in their readiness checks, and this is not currently supported out-of-the-box by spring-boot-actuator.

To this end I intend to follow the guidelines at https://docs.spring.io/spring-boot/docs/current/reference/html/production-ready-features.html#writing-custom-healthindicators

However it occurred to me that this would be potentially useful for the broader Spring community so I thought I would ask whether you would consider a submission of a pull request to spring-boot-actuator to add this functionality, or if you would prefer to leave that outside the project.

[wilkinsona]

Thanks for the offer of a pull request. We don't have any support for ArangoDB in Spring Boot itself, but there is a starter that is maintained by the ArangoDB team which includes a health indicator. I'd recommend using this starter if it meets your needs. If it doesn't meet you needs, I think any enhancements should be made in the ArangoDB starter rather than us duplicating that effort in Spring Boot itself.

[oliverlockwood]

Thanks @wilkinsona for the pointers. That seems a sensible approach.