Join into a existing (newly created) network

General Discussions
1

Hi I want to join my gitlab service into my postfix created network:

in postfix docker-compose.yml:

networks:
  front:
    driver: bridge
    ipam:
      driver: default
      config:
        - subnet: 172.16.202.0/24

i tried to reach this network within gitlab docker-compose.yml with no success:

version: '3.6'
services:
  web:
    image: 'gitlab/gitlab-ee:latest'
    restart: always
    hostname: 'gitlab.myjabber.site'
    environment:
      GITLAB_OMNIBUS_CONFIG: |
        external_url 'https://gitlab.myjabber.site'
        gitlab_rails['gitlab_shell_ssh_port'] = 2289
        # Add any other gitlab.rb configuration here, each on its own line
        #pages_external_url "http://pages.myjabber.site" # not a subdomain of external_url
        #pages_nginx['redirect_http_to_https'] = true
        gitlab_rails['smtp_enable'] = true
        gitlab_rails['smtp_address'] = 172.16.202.2
        gitlab_rails['smtp_port'] = 587
        gitlab_rails['smtp_authentication'] = "plain"
        #gitlab_rails['smtp_enable_starttls_auto'] = true
        networks:
           front:
              ipv4_address: 172.16.202.3
    ports:
      - '80:80'
      - '443:443'
      - '2289:22'
    volumes:
      - '$GITLAB_HOME/config:/etc/gitlab'
      - '$GITLAB_HOME/logs:/var/log/gitlab'
      - '$GITLAB_HOME/data:/var/opt/gitlab'
    shm_size: '256m'