version: "3"

services:

  webapp:
    image: php:7-apache
    environment:
      DB_HOST: database
    ports:
      - "8080:80"
    labels:
      # expose an ingress
      katenary.io/ingress: 80
      # DB_HOST is actually a service name
      katenary.io/env-to-service: DB_HOST
    depends_on:
      - database

  database:
    image: mariadb:10
    environment:
      MARIADB_ROOT_PASSWORD: foobar
      MARIADB_USER: foo
      MARIADB_PASSWORD: foo
      MARIADB_DATABASE: myapp
    labels:
      # because we don't provide "ports" or "expose", alert katenary
      # to use the mysql port for service declaration
      katenary.io/ports: 3306