[docs] Fix Apache reverse proxy config

[Frodox]

• I have updated the appropriate documentation

[mention-bot]

@Frodox, thanks for your PR! By analyzing the history of the files in this pull request, we identified @tardyp, @sa2ajj and @gracinet to be potential reviewers.

[codecov]

Codecov Report

Merging #3299 into master will not change coverage.
The diff coverage is n/a.

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  Files         320      320           
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  Hits        29367    29367           
  Misses       3925     3925

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[Frodox]

Just found that it breaks #3174. What is correct way to resolve it? Should I add one more config for CentOS/RHEL/Fedora?
Should I add configs into some examples dir?
According to ws-apache-docs ProxyPass should match some Path (as in nginx config), like

ProxyPass "/ws2/"  "ws://echo.websocket.org/"
ProxyPass "/wss2/" "wss://echo.websocket.org/"

current one

ProxyPass ws://127.0.0.1:8020/ws

can't be working one because it doesn't match any path. So it can be only like

ProxyPass /ws ws://127.0.0.1:8020/ws

[Frodox]

from conversation to #3174 it looks like it wrong PR.
Should there be

ProxyPass /ws !

now?

[gracinet]

Agh sorry for the mess, indeed I failed the copy-paste from my running systems. The /ws is indeed missing, that line should have been:

       ProxyPass /ws ws://localhost:8011/ws
      ProxyPassReverse /ws ws://localhost:8011/ws

ProxyPass /ws !, together with gets back to the prior version, that didn't work for me on Debian 9, hence motivating the prior change.

Just adding the missing /ws would probably be simpler than enclosing in a (and would match what I have in production on Debian 8 and 9). If that also works for you, then I'd prefer it

[Frodox]

@gracinet what is meaning of ProxyPass /ws ! ? So, should it be returned with note about Debian9 ? What happens without this option?

[gracinet]

I works, without ProxyPass /ws ! for both Debian 8 and 9, but I did not test it with the re-added

That ! directive is meant to prevent proxying the given URI, and could be used at some point to dispatch between non-proxied / differently proxied nested locations. Everything looks as if its scope changed between the two Debian versions, and it started blocking also what was in <Location /ws>

[tardyp]

thanks guys!