CaboLabs/EHRServer

Hi
I have a question. I tried setting up ehrserver in docker using the following:

version: '3.0'
services:
  web:
    image: ehrserver2
    ports:
      - "8080:8080"
    volumes:
      - ./terminology:/app/terminology
      - ./grails-app/conf/:/app/conf
    depends_on:
      - db
    environment:
      - EHRSERVER_MYSQL_DB_HOST=db
      - EHRSERVER_MYSQL_DB_PORT=3306
      - EHRSERVER_MYSQL_DB_USERNAME=ehrserver2
      - EHRSERVER_MYSQL_DB_PASSWORD=ehrserver2
      - EHRSERVER_DB_NAME=ehrserver2
      - EHRSERVER_ALLOW_WEB_USER_REGISTER=false
      - EHRSERVER_REST_SECRET=d9507256-e461-4336-a6ec-2f412796f134
  db:
    image: mysql:5.7
    volumes:
      - database:/var/lib/mysql
    environment:
      - MYSQL_DATABASE=ehrserver2
      - MYSQL_USER=ehrserver2
      - MYSQL_PASSWORD=ehrserver2
      - MYSQL_ROOT_PASSWORD=root
volumes:
  database: {}

The thing is ehrserver cannot connect to the DB. It always ends up at this point where hibernate cannot connect to the mysql server. am i setting up something wrong?
I am using the wargenerated by grails war with tomcat8-jdk8