* core: Plugins can register listener networks
This can be useful for custom listeners.
This feature/API is experimental and may change!
* caddyhttp: Expose server listeners
This allows users to, for example, get upstreams from multiple SRV
endpoints in order (such as primary and secondary clusters).
Also, gofmt went to town on the comments, sigh
* fileserver: Support virtual file systems (close#3720)
This change replaces the hard-coded use of os.Open() and os.Stat() with
the use of the new (Go 1.16) io/fs APIs, enabling virtual file systems.
It introduces a new module namespace, caddy.fs, for such file systems.
Also improve documentation for the file server. I realized it was one of
the first modules written for Caddy 2, and the docs hadn't really been
updated since!
* Virtualize FS for file matcher; minor tweaks
* Fix tests and rename dirFS -> osFS
(Since we do not use a root directory, it is dynamic.)
Hahaha this is the ultimate "I have no idea what I'm doing" commit but it
compiles and the tests pass and I declare victory!
... probably broke something, should be tested more.
It is nice that the protobuf dependency becomes indirect now.
* reverseproxy: Implement retry count, alternative to try_duration
* Add Caddyfile support for `retry_match`
* Refactor to deduplicate matcher parsing logic
* Fix lint
See https://caddy.community/t/using-forward-auth-and-writing-my-own-authenticator-in-php/16410, apparently it didn't work when `copy_headers` wasn't used. This is because we were skipping adding a handler to the routes in the "good response handler", but this causes the logic in `reverseproxy.go` to ignore the response handler since it's empty. Instead, we can just always put in the `header` handler, even with an empty `Set` operation, it's just a no-op, but it fixes that condition in the proxy code.
