Spring Boot Devtools Remote cause error at Pivotal Cloud Foundry

Question

Sorry, cant post images with low reputation) Here is my settings: Spring Boot: 2.3.0.RELEASE

I have this app working at Pivotal Cloud Foundry. I have runing Remote App and after build through IDE or using

./gradlew clean assemble

I get Exception in thread "File Watcher" java.lang.IllegalStateException: Unexpected 404 NOT_FOUND response uploading class files

Are you intentionally trying to run Dev Tools here? You wouldn't normally do this, and I quote from the docs Remote support is opt-in as enabling it can be a security risk.. docs.spring.io/spring-boot/docs/2.3.1.RELEASE/reference/html/…. It should also normally be disabled when you deploy to CF with the Java buildpack. — Daniel Mikusa
For development purposes to push code changes to remote and automatically make mods and test them immediately. — Oleg Kamuz
It does not seem like it's able to connect to your app. If you run cf logs on your app, do you see any requests to the app? Do you require a proxy to talk to the Internet? — Daniel Mikusa
2020-07-16T13:51:24.54+0300 [RTR/7] OUT lsb-tired-elephant-pw.cfapps.io - [2020-07-16T10:51:24.525144702Z] "POST /.~~spring-boot!~/restart HTTP/1.1" 404 2264 6745 "-" "Java/12.0.2" "10.10.66.251:55238" "10.10.148.57:61198" x_forwarded_for:"109.251.102.101, 10.10.66.251" x_forwarded_proto:"https" vcap_request_id:"e4b853b4-e8b5-4814-4084-b7afb7e2947e" response_time:0.020901 gorouter_time:0.000150 app_id:"bbe49967-be62-492f-830f-a40170e0d5af" app_index:"0" x_cf_routererror:"-" x_b3_traceid:"752f82bc4d56f675" x_b3_spanid:"752f82bc4d56f675" x_b3_parentspanid:"-" b3:"752f82bc4d56f675-752f8... — Oleg Kamuz
Can problem be connected to whether I`m using static or dynamical ip address? — Oleg Kamuz

Daniel Mikusa Daniel Mikusa · Accepted Answer · 2020-08-05T13:56:41

Ok, so after looking through your demo app I believe the issue is that you're using Spring Webflux and that's not supported at the moment.

The remote devtools functionality is only available with Spring WebMVC & Servlet. See this Github issue for reference: https://github.com/spring-projects/spring-boot/issues/13092#issuecomment-387350811