Unable to change job manager port when launching session cluster on Docker

[Papadopoulos, Konstantinos]

Hello all,

I am trying to launch an Apache Flink session cluster on Docker using Docker 
Compose and following the respective tutorial:
https://ci.apache.org/projects/flink/flink-docs-stable/ops/deployment/docker.html#flink-with-docker-compose
The default job manager port (i.e., 8081) is in use on my host so the cluster 
fails to launch.
I tried to change the configuration from the respective service definition on 
docker-compose.yml (e.g., services -> jobmanager -> ports: "5000:5000") with no 
success; job manager container seems to launch on the default port.
Can anybody help me to proceed with this?

Thanks in advance,
Konstantinos

P.S.: My docker-compose.yml is the following:

version: "2.1"
services:
  jobmanager:
    image: ${FLINK_DOCKER_IMAGE_NAME:-flink}
    expose:
      - "6123"
    ports:
      - "5000:5000"
    command: jobmanager
    environment:
      - JOB_MANAGER_RPC_ADDRESS=jobmanager

  taskmanager:
    image: ${FLINK_DOCKER_IMAGE_NAME:-flink}
    expose:
      - "6121"
      - "6122"
    depends_on:
      - jobmanager
    command: taskmanager
    links:
      - "jobmanager:jobmanager"
    environment:
      - JOB_MANAGER_RPC_ADDRESS=jobmanager