Including pod definitions. Swarms not starting e.g. "Invalid arguments provided."

swarm.json

{
  "name": "magebox",
  "components": {
    "app": {
      "pod": "children"
    },
    "app/php": {
      "image": "registry.giantswarm.io/designhunger/magebox-magento:latest",
      "ports": [9000],
      "volumes": [
        {
          "path": "/code",
          "size": "2 GB"
        }
      ],
      "links": [
        {
          "component": "mysql",
          "target_port": 3306,
          "alias": "mysql"
        }
      ]
    },
    "app/nginx": {
      "image": "registry.giantswarm.io/designhunger/magebox-nginx:latest",
      "ports": [80],
      "links": [
        {
          "component": "app/php",
          "target_port": 9000,
          "alias": "php"
        }
      ],
      "volumes": [
        {
          "volumes-from": "app/php"
        }
      ],
      "domains": {
        "80": "magebox-designhunger.gigantic.io"
      }
    },
    "mysql": {
      "image": "mariadb:10.1.13",
      "ports": [3306],
      "env": {
        "MYSQL_ROOT_PASSWORD": "password",
        "MYSQL_DATABASE": "magento",
        "MYSQL_USER": "magento",
        "MYSQL_PASSWORD": "password"
      }      
    }
  }
}