CODEWITHSUNDEEP
javaspringdockerspring-boot
Jarle Hansen
Jarle Hansen

Reputation: 1993

debug spring-boot in docker

For some reason I have issues connecting remote debug to a spring-boot app running inside docker. I start the java app with:

java -Xdebug -Xrunjdwp:server=y,transport=dt_socket,address=8000,suspend=n -jar app.jar

For docker I expose these ports on docker-compose:

ports:
- "8080:8080"
- "8000:8000"

However, the debugger is not able to connect on port 8000. It works when I run the server locally but not inside docker. Any idea why?

Docker ps output:

CONTAINER ID        IMAGE                       COMMAND                CREATED               STATUS              PORTS                                            NAMES
0d17e6851807        pocmanager_manager:latest   "/bin/sh -c 'java -D   3 seconds ago       Up 2 seconds        0.0.0.0:8000->8000/tcp, 0.0.0.0:8080->8080/tcp   pocmanager_manager_1   
35ed2e2c32bc        redis:latest                "/entrypoint.sh redi   14 seconds ago      Up 13 seconds       0.0.0.0:6379->6379/tcp                           pocmanager_redis_1

Upvotes: 20

Views: 27033

Answers (5)

rbento
rbento

Reputation: 11608

I had an issue connecting to a Spring Boot application running with Docker Compose and solved it with the settings below:

Project structure

- project
    - some-api
        - src
        - Dockerfile
        - build.gradle
    - docker-compose.yml

project/docker-compose.yml

version: "3.9"
services:
  api:
    image: rbento/some-api
    build:
      context: ./some-api
      dockerfile: Dockerfile
    container_name: api
    ports:
      - 8080:8080
      - 5005:5005

project/some-api/Dockerfile

FROM adoptopenjdk/openjdk11:ubi
COPY build/libs/some-api-1.0.0.jar api.jar
ENTRYPOINT ["java","-agentlib:jdwp=transport=dt_socket,address=*:5005,server=y,suspend=n","-Djava.security.egd=file:/dev/./urandom","-jar","/api.jar"]

IntelliJ IDEA

Create a Remote JVM Debug configuration, like so:

  • Name: some-api-debug
  • Debugger mode: Attach to remote JVM
  • Host: localhost
  • Port: 5005
  • Command line arguments for remote JVM:
    -agentlib:jdwp=transport=dt_socket,server=y,suspend=n,address=*:5005
  • Use module classpath: some-api.main

Debugging

  • Run the application with docker-compose up
  • Then debug via IntelliJ IDEA

Output

Connected to the target VM, address: 'localhost:5005', transport: 'socket'

Environment

  • macOS Big Sur 11.5.2
  • IntelliJ IDEA CE 2021.2.1
  • Docker Version 3.6.0 (3.6.0.5487)

Upvotes: 3

Marcus K.
Marcus K.

Reputation: 1040

For me it was not enough to just specify the debug port within the address command line parameter. I also needed to wildcard all ip addresses by prefixing the port with *::

java -agentlib:jdwp=transport=dt_socket,address=*:8000,server=y,suspend=n -jar spring-app.jar

Upvotes: 2

nekperu15739
nekperu15739

Reputation: 3698

i have to realize that in the dockerFile the Expose command only do the half of work, this mean that only expose the port inside the docker, but not outside, in your example the result will be like this:

enter image description here

Debug works with the JAVA_OPTS and remote debug, the dockerFile looks like this:

FROM frolvlad/alpine-oraclejdk8:slim
VOLUME /tmp
ADD gs-spring-boot-docker-0.1.0.jar app.jar
RUN sh -c 'touch /app.jar'
ENTRYPOINT [ "sh", "-c", "java $JAVA_OPTS -jar /app.jar" ]

and executing this command:

docker run -e "JAVA_OPTS=-agentlib:jdwp=transport=dt_socket,address=8000,server=y,suspend=y" -p 8080:8080 -p 8000:8000 -t springio/gs-spring-boot-docker

As you can see, you should expose the debug port, during the run, in my case(eclipse) 8000

enter image description here

enter image description here

Upvotes: 12

SWiggels
SWiggels

Reputation: 2296

Hi I faced the same problem.

I added the following to the entrypoint in the Dockerfile:

"-agentlib:jdwp=transport=dt_socket,address=8000,server=y,suspend=n"

Now it looks like this:

FROM java:8
VOLUME /tmp
ADD realName*.jar app.jar
EXPOSE 4786
RUN sh -c 'touch /app.jar'
ENTRYPOINT
["java","-agentlib:jdwp=transport=dt_socket,address=8000,server=y,suspend=n","-Djava.security.egd=file:/dev/./urandom","-jar","/app.jar"]

I did not Exposeport 8000 in the Dockerfile.

Hope this helps.

Upvotes: 10

Palanivelrajan
Palanivelrajan

Reputation: 121

I think the reason for this might be, your Virtual Box VM configuration does not tunnel the debug port to the host machine.

Check this link https://github.com/boot2docker/boot2docker/blob/master/doc/WORKAROUNDS.md

Basically, in your case, you have to command prompt and run

VBoxManage modifyvm "boot2docker-vm" --natpf1 "tcp-port8000,tcp,,8000,,8000";

Note : Make sure VBoxManage is in your PATH

Upvotes: 0

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