Spring Boot now deploys both annotation-based and functional endpoints
under the same `HttpHandler`; this means the currently auto-configured
`MetricsWebFilter` is instrumenting all endpoints to produce metrics.
There is no need for a WebFlux functional specific support.
This commit removes mentions of `RouterFunctionMetrics` in the docs and
deprecates that class.
Closes gh-12833
Prior to this commit, the metrics `WebFilter` would handle exceptions
flowing through the pipeline and extract tag information right away.
Since error handling turns the exception information into error HTTP
responses later in the chain, the information extracted from the
response earlier is invalid.
In this case, the "status" information could be "200" whereas error
handlers would later set that status to "500".
This commit delays the tags extraction later in the process, right
before the response is comitted. The happy path is not changed, as
handlers signal that the response is fully taken care of at that point.
Fixes gh-11514
Previously to this commit, if a `@ControllerEndpoint`,
`@RestControllerEndpoint` or `@ServletEndpoint` annotated bean was
proxied, the endpoint wasn't properly detected.
This commit makes sure that annotation retrieval works on the user class
while preserving the get (vs. find) retrieval semantic
Closes gh-12441
Brian Clozel
Stephane Nicoll
DK Lee
Madhura Bhave
Ken Kwon
Andy Wilkinson
Johnny Lim
Phillip Webb
Spring Buildmaster