从 Docker 容器内部，如何连接到同一容器内侦听的另一个进程？

Question

I have spent a couple of hours researching this and the consensus seems to be that using host.docker.internal instead of localhost should allow one process within a container to connect to another process within the same container.

However, host.docker.internal does not work for me.

Environment:

• Docker Desktop 4.6.1 running on Windows 10
• docker run command running on WSL2 Ubuntu

Command:

• docker run -p 80:80

Error

• Connection timeout

Dockerfile contents

FROM openjdk:17-alpine
COPY xxx/target/AAA.jar AAA.jar
COPY xxx/target/BBB.jar BBB.jar
COPY xxx/target/CCC.jar CCC.jar
COPY ./dockerboot.sh dockerboot.sh 
ENTRYPOINT ["sh", "-c", "./dockerboot.sh"]
EXPOSE 80

dockerboot.sh contents

java -jar AAA.jar &
java -jar BBB.jar &
java -jar CCC.jar &
wait

The AAA , BBB , CCC jars contain java Springboot applications listening on ports 80, 8081, and 8082 respectively.

Answer 1

The answer is to just use localhost or 127.0.0.1 .

It turns out the root cause of my issue was unrelated to Docker.networking:

One of the microservice jars was malformed ( no main manifest attribute ) and was not starting up correctly, hence, failing to listen on port 8081 and causing Connection refused .