CODEWITHSUNDEEP
windowsdockerdocker-composedocker-swarm
elp
elp

Reputation: 870

Can not reach docker container running in a swarm cluster

If that's interesting: OS: WIN10 (cygwin), code written in Java.

I followed this example.

I'd expect to reach the service in front of the container, which is running on port 80, using myvm1IP:80 (browser ir curl). Somehow this does not work. Or am I missunderstoonding the port mapping of the service?

*:8080->80/tcp

I got a running docker swarm cluster consisting of 2 nodes. I am able to ping both of the running VMs

I already downgraded the version as there were issues with more recent version numbers. Information about the engine using docker inspect vmName:

    "Engine": {
        "EngineVersion": "18.06.1-ce",
        "Labels": {
            "provider": "hyperv"
        },

I executed the following docker-compose.yml: 

version: "3"

services:
  web:
    image: elps/articleservice:1.1.0.4
    deploy:
      replicas: 2
      restart_policy:
        condition: on-failure
    ports:
      - "8080:80"
    environment:
      - MYSQL_HOST=192.168.178.82
      - MYSQL_DB=article
      - MYSQL_USER=root
      - MYSQL_PASSWORD=abcdefg
    networks:
      - webnet    

networks:
  webnet:

Both replicas started successfully and are able to connect to the local running database (assuming that, as I had a look at the logs and everything was looking fine). The container are up and running.

Output of docker ps -a

CONTAINER ID        IMAGE                         COMMAND                  CREATED             STATUS                      PORTS               NAMES
979ed7ea88b7        elps/articleservice:1.1.0.4   "java -jar articlese…"   27 minutes ago      Up 27 minutes               8080/tcp            getstartedlab_web.1.j1j41so8pz6atxqnq9fqqquk7
7684c3667025        elps/articleservice:1.1.0.4   "java -jar articlese…"   27 minutes ago      Up 27 minutes               8080/tcp            getstartedlab_web.2.r4kadvztiwgpckkuannnhcsea

Output of docker service ls 

ID                  NAME                MODE                REPLICAS            IMAGE                         PORTS
gvyi9moxtpvq        getstartedlab_web   replicated          2/2                 elps/articleservice:1.1.0.4   *:8080->80/tcp

Output of docker-machine ls

NAME    ACTIVE   DRIVER   STATE     URL                         SWARM   DOCKER        ERRORS
myvm1   *        hyperv   Running   tcp://192.168.178.88:2376           v18.06.1-ce
myvm2   -        hyperv   Running   tcp://192.168.178.89:2376           v18.06.1-ce

When I try to execute curl myvmIP:80 I recieve

Failed to connect to 192.168.178.88 port 80: Connection refused

as response. I'd expect recieving a 404 error code as there is no mapping for /. Am I wrong with this?

Upvotes: 3

Views: 811

Answers (1)

elp
elp

Reputation: 870

Okay, so I simply tested switching all the ports I had, as I was kind of sure there was something wrong.

  • The application itself and container was running on default port (8080)
  • The server was redirecting incoming traffic on port 8080 to containers port 80 (where obviously is running nothing)

After switching the ports in service config (docker-compose.yml) it works fine.

So the working docker-compose.yml looks like this:

version: "3"

services:
  web:
    image: elps/articleservice:1.1.0.4
    deploy:
      replicas: 2
      restart_policy:
        condition: on-failure
    ports:
      - "80:8080"
    environment:
      - MYSQL_HOST=192.168.178.82
      - MYSQL_DB=article
      - MYSQL_USER=root
      - MYSQL_PASSWORD=abcdefg
    networks:
      - webnet    

networks:
  webnet:

So incoming traffic gets redirected as follows:

Incoming traffic -> 80:Service->8080:Container

Upvotes: 2

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