Update nginx reverse proxy docs

[eeyrjmr]

The present documentation on using nginx includes the bare minimum required ( proxy_pass). However, there are 4 more lines required to ensure gitea receives key header information. This is useful for logs

[silverwind]

X-Real-IP is redundant there, the remote IP is already in X-Forwarded-For.

[silverwind]

Also Host seems unecessary as that is nginx's default behaviour according to https://stackoverflow.com/a/39716709/808699.

Edit: I guess that one has a purpose actually so gitea does not receive localhost.

[eeyrjmr]

X-Real-IP is redundant there, the remote IP is already in X-Forwarded-For.

Depends. X-Real-IP is the ip of interest while X-Forwarded-For will contain all the hops (and the last one is typically the ip of interest).

What header is used within gitea for logging. If it utilises the X-Forwarded-For then yes X-Real-IP can be dropped

[codecov-commenter]

Codecov Report

❗ No coverage uploaded for pull request base (main@bf2867d). Click here to learn what that means.
The diff coverage is n/a.

@@           Coverage Diff           @@
##             main   #18922   +/-   ##
=======================================
  Coverage        ?   46.58%           
=======================================
  Files           ?      854           
  Lines           ?   122565           
  Branches        ?        0           
=======================================
  Hits            ?    57098           
  Misses          ?    58573           
  Partials        ?     6894           

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update bf2867d...f68836b. Read the comment docs.

[silverwind]

What header is used within gitea for logging

REVERSE_PROXY_LIMIT: 1: Interpret X-Forwarded-For header or the X-Real-IP header and set this as the remote IP for the request.

It is either X-Forwarded-For (semi-standard) or X-Real-IP (non-standard), not both. This should not have landed.

[eeyrjmr]

What header is used within gitea for logging

REVERSE_PROXY_LIMIT: 1: Interpret X-Forwarded-For header or the X-Real-IP header and set this as the remote IP for the request.

It is either X-Forwarded-For (semi-standard) or X-Real-IP (non-standard), not both. This should not have landed.

Debatable.
There is plenty of recommendations to include both and this PR was written while helping an individual on discord deal with missing log IP (followed existing docs)

Maybe dropping X-Real-IP but has that been tested ?