Error when upstream server unreachable

Error occurs when Kong pulls the OpenAPI servers entity to generate an upstream but those are not reachable. In Kong each target is only defined by its IP and port. So when you have entries in servers that differ by protocol (mix of http and https for example) or have a different uri, then Kong cannot handle that. Hence the error that server urls should not differ other than host or port.
Important here: it is assumed that the OpenAPI spec defines where Kong can find the upstream services. So they are references to the internal network. This probably warrants a configuration setting to do this differently.

Start at the OpenAPI servers handling and upstream-generation path, then reproduce the error with server entries that differ by protocol or URI. Determine whether the intended behavior is to treat servers as internal upstream references or add a configuration option; done should include a defined behavior for unreachable or differing server URLs.

Written by the indexing model from the issue text.