request help: configure multiple servers in apisix

[JanLi-air]

Issue description

APISIX can be much more multi-functional if it can support configuring multiple servers.
For example, if we want to use APISIX to support 3 kinds of requests:

1. normal http and https
2. http and https with proxy protocol
3. https with mtls

Although all the 3 kinds of requests use http or https, the real protocol has subtle difference.

Currently APISIX can configure one server with both http, https, http with proxy protocl, and https with proxy protocol.
But there are two issues:

1. You cannot configure both normal https and https-mtls in the same server.
2. The real_ip_header needs to be configured differently between http/https proxy protol and normal http/https.

So I think APISIX needs to way to configure multi-servers to make APISIX more versatile.

Environment

• apisix version (cmd: apisix version): 2.0
• OS: Linux