Código completo para definição dos pré-requisitos de ambiente para o curso de integração contínua com testes

docker-compose.yml

version: "3"
services:
    pg-tasks:
        container_name: pg-tasks
        image: postgres:9.6
        ports:
            - 5433:5432
        environment: 
            - POSTGRES_DB=tasks
            - POSTGRES_PASSWORD=password
 
    sonarqube:
        container_name: sonar
        image: sonarqube:7.9.2-community
        ports:
            - "9000:9000"
        networks:
            - sonarnet
        environment:
            - sonar.jdbc.url=jdbc:postgresql://pg-sonar:5432/sonar
        depends_on:
            - pg-sonar
        volumes:
            - sonarqube_conf:/opt/sonarqube/conf
            - sonarqube_data:/opt/sonarqube/data
            - sonarqube_extensions:/opt/sonarqube/extensions
            - sonarqube_bundled-plugins:/opt/sonarqube/lib/bundled-plugins
 
    pg-sonar:
        container_name: pg-sonar
        image: postgres:9.6
        networks:
            - sonarnet
        environment:
            - POSTGRES_USER=sonar
            - POSTGRES_PASSWORD=sonar
        volumes:
            - postgresql:/var/lib/postgresql
            - postgresql_data:/var/lib/postgresql/data
 
    selenium-hub:
        image: selenium/hub:3.141.59-zinc
        container_name: selenium-hub
        networks:
            - seleniumGrid
        ports:
            - "4444:4444"
 
    chrome:
        image: selenium/node-chrome:3.141.59-zinc
        container_name: Chrome-1
        networks:
            - seleniumGrid
        depends_on:
            - selenium-hub
        environment:
            - HUB_HOST=selenium-hub
            - HUB_PORT=4444
            - NODE_MAX_INSTANCES=2
            - NODE_MAX_SESSIONS=2
 
    chrome2:
        image: selenium/node-chrome:3.141.59-zinc
        container_name: Chrome-2
        networks:
            - seleniumGrid
        depends_on:
            - selenium-hub
        environment:
            - HUB_HOST=selenium-hub
            - HUB_PORT=4444
            - NODE_MAX_INSTANCES=2
            - NODE_MAX_SESSIONS=2
 
networks:
    sonarnet:
    seleniumGrid:
 
volumes:
  sonarqube_conf:
  sonarqube_data:
  sonarqube_extensions:
  sonarqube_bundled-plugins:
  postgresql:
  postgresql_data:

WCaquino, seu arquivo docker image: sonarqube não funciona.