healthcheck endpoint

[ajgon]

This PR adds a /health endpoint which does nothing more than returning plaintext OK response. It is useful for service discovery tools (consul/kubernetes etc.), to quickly say, that service is alive and running.

[maciej-orba]

@krallin can you please include this PR in next release? its nice just for visibility that service responds and there are no deathlocks et.

[neurosnap]

Greetings! Thanks for submitting this PR and sorry for the long wait. Is there a reason why you couldn't use the / endpoint for the healthcheck? It's a relatively small html response.

[ajgon]

@neurosnap Even better, you can use HEAD / check and have no response at all (just the headers). Eventually I settled up with this solution, since it works in consul - I'm not sure if it works in other monitoring tools, thus GET may be still viable.

I agree, GET / is small, but still it requires way more work (relatively) to render this HTML than sending simple two-byte string. Also monitoring tool, doesn't care about response, but still needs resources to process it. I know, this may sound insignificant and irrelevant, but this stuff tends to add up, when you monitor multiple services very often.

So, at the end of the day, it's your call :) Most of the services, implement /health endpoint in one way or another, so I think it's the way to go. However, there are some other (like Gitea), which support HEAD / and call it a day.

[neurosnap]

Fair enough, thanks for the input. I don't see any harm in including this endpoint.