Docker-compose does not expose port properly

Question

So I have the following Dockerfile:

FROM adoptopenjdk/openjdk13-openj9:alpine-jre

WORKDIR /opt/Lavalink

COPY Lavalink.jar Lavalink.jar
COPY application* ./

RUN if [[ -f "./application.local.yml" ]]; then mv "./application.local.yml" "./application.yml"; fi

EXPOSE 2333

CMD ["java", "-jar", "Lavalink.jar"]

which is then launched by the following docker-compose.yml:

version: '2.4'
services:
  lavalink:
    network_mode: host
    container_name: lavalink
    image: skyrabot/lavalink:main
    restart: always
    ports:
      - '2333:2333'

However, when I try to connect to the service or check docker ps, I see that no ports are published.

Output of docker ps:

> docker ps
CONTAINER ID        IMAGE                    COMMAND                  CREATED             STATUS              PORTS                                            NAMES
e35e7cdea0a4        skyrabot/lavalink:main   "java -jar Lavalink.…"   7 minutes ago       Up 7 minutes                                                         lavalink

Any idea on what I could be doing wrong here?

user_9635150 · Answer

The problem is in the line of network_mode: host. When providing this option Docker will use the host network rather than bridging it, and it will completely ignore configured ports. You should disable / remove the line, or change it to network_mode: "bridge". For more information see https://docs.docker.com/compose/compose-file/compose-file-v2/#network_mode

Docker-compose does not expose port properly

1 Answers