RSocket's EmbeddedServerAutoConfiguration does not back off if spring-web is absent

[olegz]

RSocket integration in spring-cloud-function has no dependency on anything web, yet spring-boot-starter-rsocket brings spring-web into the classpath. Trying to exclude it results in variety of classpath errors which are easily fixable until the EmbeddedServerAutoConfiguration issue (see stack trace below)

Caused by: org.springframework.boot.autoconfigure.condition.OnBeanCondition$BeanTypeDeductionException: Failed to deduce bean type for org.springframework.boot.autoconfigure.rsocket.RSocketServerAutoConfiguration$EmbeddedServerAutoConfiguration.reactorResourceFactory
	at org.springframework.boot.autoconfigure.condition.OnBeanCondition$Spec.deducedBeanTypeForBeanMethod(OnBeanCondition.java:517) ~[spring-boot-autoconfigure-2.4.3.jar:2.4.3]
	at org.springframework.boot.autoconfigure.condition.OnBeanCondition$Spec.deducedBeanType(OnBeanCondition.java:506) ~[spring-boot-autoconfigure-2.4.3.jar:2.4.3]
	at org.springframework.boot.autoconfigure.condition.OnBeanCondition$Spec.<init>(OnBeanCondition.java:429) ~[spring-boot-autoconfigure-2.4.3.jar:2.4.3]
	... 85 common frames omitted
Caused by: java.lang.ClassNotFoundException: org.springframework.http.client.reactive.ReactorResourceFactory
	at java.net.URLClassLoader.findClass(URLClassLoader.java:382) ~[na:1.8.0_252]

After briefly discussing it with @wilkinsona there seems to be a missing condition for backing-off EmbeddedServerAutoConfiguration if certain dependencies are not present.

[snicoll]

Thanks for the report.

Unrelated but the inner classes are named AutoConfiguration and shouldn't really.