0

I am using docker-compose to start two containers (named fd & fl4j). Second container connects to the first on startup.

If I just use "host" networking, and plain "docker run" everything works fine.

With docker-compose and a defined bridge network (loggernw) the second container fails to connect to the first. May not be relevant but stating - the second container is a java spring-boot app.

Additional info: Even without docker-compose but using a "docker run" and a defined bridge network, the connection attempt fails. Also, within the second app, I am using the string "127.0.0.1" to attempt connection.

docker-compose below -

version: '3.8'
services:
  fd:
    image: fluentwithes
    container_name: fd
    ports:
      - 24224:24224
    expose:
      - "24224"
    volumes:
      - /home/hrishikesh/work/bitbucket/logger/integration/docker/runs/fluentd:/fluentd/etc
    networks:
      - loggernw
  fl4j:
    image: fluentl4java
    container_name: fl4j
    ports:
      - 9090:9090
    expose:
      - "9090"
    networks:
      - loggernw
networks:
  loggernw:
    driver: bridge
Hrishikesh V K
  • 31
  • 4
  • I was having same problem, it was due to one container was depend on other as @thompson given in his ans. You can try https://stackoverflow.com/a/61026377/6310485. – harpal Jun 27 '20 at 13:12

1 Answers1

2

Probably the second container tries to connect before the first is running properly. Try to use depends_on in the second container as given below. However, i think this only prevents the second container from starting before the frist started. You still might have the issue because the first did not finish startup in time. Then your service in the second has to do some retries. So maybe restart: always could be enough.

version: '3.8'
services:
  fd:
    image: fluentwithes
    container_name: fd
    ports:
      - 24224:24224
    expose:
      - "24224"
    volumes:
      - /home/hrishikesh/work/bitbucket/logger/integration/docker/runs/fluentd:/fluentd/etc
    networks:
      - loggernw
  fl4j:
    depends_on: 
      - fd
    restart: always
    image: fluentl4java
    container_name: fl4j
    ports:
      - 9090:9090
    expose:
      - "9090"
    networks:
      - loggernw
networks:
  loggernw:
    driver: bridge

Edit:

127.0.0.1 is wrong i think. You want put the service name there instead. The Ip might change. Try to put in second container "fd:24224" as connection string. Further information found here. https://docs.docker.com/network/bridge/

thompson
  • 179
  • 1
  • 12
  • Thanks. Yes, the second container tries before first is up. However, even if I stop the second one and ensure that first one is running and then start second again, still same issue. The first one is then running ok and accessible externally via curl. – Hrishikesh V K Jun 27 '20 at 13:11
  • Superb @thompson. Using fd:24224 as conn string in second container works. It pays to RTFM ! – Hrishikesh V K Jun 27 '20 at 13:57