Possibly incorrect information in references/configuration #services.checks

[Dkendal]

Hi all,

This section may be wrong or outdated.

It states:

Roughly translated, this section says every ten seconds, perform an HTTP GET on the root path (e.g. http://appname.fly.dev/) looking for it to return an HTTP 200 status within two seconds. The parameters of a http_check are listed below. This does not appear to be true, we had a health check on a service that had no external port and so should not have been accessible via https://appname.fly.dev/ which did pass the health check.

To make things more confusing: our service was accidentally only listening on IPv4 (0.0.0.0) and the healthchecks passed, despite the service not being available via the 6PN address - after reconfiguring the app to only listen to the IPv6 loopback it still passed healthchecks which seems to run counter to this line:

port: Internal port to connect to. Needs to be available on 0.0.0.0. Required