Set the basePath using the request context path if present

[jgcollings]

This allows the X-Forwarded-Prefix header to work correctly

fix for issue #3157

Test with the following steps:
1 - build and install into local maven repo.
2 - clone repo https://github.com/jgcollings/webfluxtest.git
3 - run the project: mvn spring-boot:run
4 - use the following curl command to get the api spec:

curl -X GET
http://localhost:8080/v2/api-docs
-H 'X-Forwarded-Host: www.acme.com'
-H 'X-Forwarded-Port: 80'
-H 'X-Forwarded-Prefix: /myprefix'
-H 'X-Forwarded-Protocol: http'

Notice that the basePath in the spec is "/myprefix"

[codecov]

Codecov Report

Merging #3158 into master will increase coverage by 0.02%.
The diff coverage is 100%.

@@             Coverage Diff              @@
##             master    #3158      +/-   ##
============================================
+ Coverage     92.91%   92.93%   +0.02%     
- Complexity     3512     3514       +2     
============================================
  Files           382      382              
  Lines          9330     9330              
  Branches        768      769       +1     
============================================
+ Hits           8669     8671       +2     
+ Misses          472      471       -1     
+ Partials        189      188       -1

Impacted Files	Coverage Δ	Complexity Δ
...tation/swagger2/web/Swagger2ControllerWebFlux.java	81.25% <100%> (ø)	5 <0> (+1)	⬆️
...umentation/spring/web/scanners/ApiModelReader.java	95.46% <0%> (+0.56%)	88% <0%> (+1%)	⬆️

[M3yo]

Hi everyone,

When this fix will be merged ?

Both controllers (webMvc and WebFlux) does not work the same regarding basePath, the X-Forwarded-Prefix is ignored in Webflux mode which make the "Try it out" feature unusable when using a reverse proxy. :(

[jgcollings]

I would like this merged soon as well. It has been a problem for us for quite a while and I have to tell developers constantly that the try it out button does not work.

[dilipkrish]

Thanks @jgcollings!