Make TrustedProxies feature backward-compatible

[zihengCat]

@appleboy @thinkerou @manucorporat

New engine.TrustedProxies feature PR2632 brings breaking changes in many usage case.

• RunTLS or run in HTTP handler directly doesn't call prepareTrustedCIDRs.
• Client IP parsing.

Related issues:

• c.ClientIP() #2697
• Remove the new trustedproxy logic from client ip parsing #2809
• Export engine.prepareTrustedCIDRs() #2814
• build(deps): bump github.com/gin-gonic/gin from 1.6.3 to 1.7.1 MurmurationsNetwork/MurmurationsServices#135

PR2692 exports an API to set TrustedProxies but not fix backward compatibility.

We need to make engine.TrustedProxies feature backward-compatible.

[menduo]

I agree.

I just wanna say that PR #2632 is crazy, nightmare.

Lots of our apps built on Gin can't be upgraded to the new version of Gin, because all of them will be broken.

Hope this will be fixed soon.

Thanks a lot.

[thinkerou]

@zihengCat @menduo please help us review #2832 , thanks!

[Bisstocuz]

Hi, I think this issue can be closed after #2887 was merged.

[appleboy]

closed via #2887