Docker extension with volume

dockerextensionwithvolume.json

{

      "type": "extensions",

      "name": "DockerExtension",

      "tags": {

        "displayName": "DockerExtension"

      },

      "apiVersion": "2016-03-30",

      "location": "[resourceGroup().location]",

            "dependsOn": [

              "[resourceId('Microsoft.Compute/virtualMachines/', variables('vmName'))]"

            ],

      "properties": {

        "publisher": "Microsoft.Azure.Extensions",

        "type": "DockerExtension",

        "typeHandlerVersion": "1.2",

        "autoUpgradeMinorVersion": true,

        "settings": {

          "compose": {

            "geoserver": {

              "image": "winsent/geoserver:2.10",
              "ports": [ "8080:8080" ]
              "volumes": [
                      "/media/geoserverdatadir:/opt/geoserver/data_dir"
              ]
            }

          }

        },

        "protectedSettings": {

        }

      }

}