WebServerFactoryCustomizer is not hit in a Springboot Webflux app - spring-boot

Question

Following Configure the Web Server , I add a NettyWebServerFactoryCustomizer
#Configuration
public class NettyWebServerFactoryCustomizer implements WebServerFactoryCustomizer<NettyReactiveWebServerFactory> {
#Override
public void customize(NettyReactiveWebServerFactory factory) {
factory.addServerCustomizers(httpServer -> {
return httpServer
.wiretap(true)
.metrics(true, s->s)
.doOnConnection(conn -> {
conn.addHandlerFirst(new ReadTimeoutHandler(50, TimeUnit.MILLISECONDS));
});
});
}
}
I have two questions:
When I run the app, the customize function is not hit. Where do I miss?
My purpose is to enable the Netty metrics, I can't find any documents about config the metrics in the application.yml file. so I add the NettyWebServerFactoryCustomizer.
The second parameter of .metrics(true, s->s) is a uriTagValue, Are there any example about how to pass in value? I just use s->s because I refer this, but this maybe can't avoid cardinality explosion, Are there any function like ServerWebExchange.getAttribute(HandlerMapping.BEST_MATCHING_PATTERN_ATTRIBUTE) simple give us the templated URL?

Answer 1

I found the workaround of the question 1: define a bean instead of implementing WebServerFactoryCustomizer
#Bean
public ReactiveWebServerFactory reactiveWebServerFactory() {
NettyReactiveWebServerFactory factory = new NettyReactiveWebServerFactory();
factory.addServerCustomizers(builder -> builder
.wiretap(true)
.metrics(true,s->s)
.accessLog(true)
.doOnConnection(conn -> {
conn.addHandlerFirst(new ReadTimeoutHandler(50, TimeUnit.MILLISECONDS));
}));
return factory;
}

Answer 2

About your question 2 : The second parameter of .metrics(true, s->s) is a uriTagValue, Are there any example about how to pass in value?
private static final Pattern URI_TEMPLATE_PATTERN = Pattern.compile("/test/.*");
#Bean
public ReactiveWebServerFactory reactiveWebServerFactory() {
NettyReactiveWebServerFactory factory = new NettyReactiveWebServerFactory();
factory.addServerCustomizers(builder -> builder
.wiretap(true)
.metrics(true,
uriValue ->
{
Matcher matcher = URI_TEMPLATE_PATTERN .matcher(uriValue);
if (matcher.matches()) {
return "/test/";
}
return "/";
}
.accessLog(true)
.doOnConnection(conn -> {
conn.addHandlerFirst(new ReadTimeoutHandler(50, TimeUnit.MILLISECONDS));
}));
return factory;
}