[Feature Request] Healthcheck

[lippertmarkus]

I really like your library and I would love to have a healthcheck feature builtin. Many applications need some time until they're fully started and often the DNS entry is updated too early as soon as a new application instance is started.

It would be great to have an option to only add hosts to the DNS cache if an HTTP healthcheck was successful. Would this be possible?

[jkeys089]

@lippertmarkus that definitely would be a nice feature. I'll leave this issue open in case anyone wants to commit some time to adding that feature in the future.

[mauricioabreu]

@lippertmarkus I know it is late but what would happen if health check determines the server is not OK?

[lippertmarkus]

@mauricioabreu Something like this would have been my idea: If the healthcheck fails the domain shouldn't be added to the cache or be removed if it's already in there. If that's the case the lookup would fail and one can react to that accordingly within the balancer_by_lua_block.

But to be honest, I currently don't require that feature. But if that's helpful for you or for anyone else then go ahead :)