{
  "layers": {
    "webserver": {
      "applications": {
        "web": {
          "image": "httpd",
          "ports": [ "80:80", "443:443" ],
          "links": [ "postfix", "memcached" ],
          "volumes": ["/var/log/httpd:/var/log/httpd"],
          "environment": {
            "VAR1": "value1",
            "VAR2": "value2"
          }
        },
        "postfix": {
          "image": "tozd/postfix"
        },
        "memcached": {
          "image": "memcached"
        }
      }
    }
  }
}