Added dynamic config and external volume capabilities

This commit introduces changes to the configuration to include
the ability to customize any number of nodes and personalities.
It also includes external volume support.

.gitignore

@@ -2,3 +2,4 @@
 .DS_Store
 packer_cache
 packer/builds
+Volumes/*

README.md

@@ -3,30 +3,131 @@
 [Playa Mesos][8] helps you quickly create [Apache Mesos][1] test environments.
 This project relies on [VirtualBox][5], [Vagrant][6], and an Ubuntu box image
 which has Mesos and [Marathon][2] pre-installed. The box image is downloadable for your
-convenience, but it can also be built from source using [Packer][9].
+convenience, but it can also be built from source using [Packer][9].  There is an external volume capability when using
+with VirtualBox provided through [REX-Ray](https://github.com/emccode/rexray).
 
 As an alternative to VirtualBox, it's possible to build and run the image on
 VMware [Fusion](https://www.vmware.com/products/fusion/) or [Workstation](https://www.vmware.com/products/workstation/).
 
 ## Requirements
 
-* [VirtualBox][5] 4.2+
+* [VirtualBox][5] 5.0.10+
 * [Vagrant][6] 1.3+
 * [git](http://git-scm.com/downloads) (command line tool)
 * [Packer][9] 0.5+ (optional)
 * VMware [Fusion](https://www.vmware.com/products/fusion/) or [Workstation](https://www.vmware.com/products/workstation/) (optional)
 * [Vagrant Plugin for VMware Fusion or Workstation](https://www.vagrantup.com/vmware) (optional)
 
+## Configuration
+The `config.json` file holds all of the configurable parameters.  By default
+there is one host deployed running the master and slave services.  Additionally
+both Chronos and Marathon frameworks are running.  Set the appropriate hostnames, IP
+addresses, VM settings, and other parameters in this file.
+
+### Example All-In-One Master
+```json
+{
+  "platform": "virtualbox",
+  "box_name": "playa_mesos_ubuntu_14.04_201601041324",
+  "base_url": "http://downloads.mesosphere.io/playa-mesos",
+  "hosts": {
+    "mesos-master": {
+      "ip": "10.141.141.10",
+      "vm_ram": "2048",
+      "vm_cpus": "2"
+    }
+	}
+}
+```
+
+### Example All-In-One Master with External Volumes
+The `external_volumes` parameter can be introduced which leverages VirtualBox
+to provide external volume support for tasks.  The external volume functionality
+means that both the `Mesos containerizer` and `Docker containerizer` can
+define external volumes that get attached to tasks.  See [Mesos](https://github.com/emccode/mesos-module-dvdi)
+and [Docker](https://github.com/emccode/rexray) for examples.
+
+
+
+```json
+{
+  "platform": "virtualbox",
+  "box_name": "playa_mesos_ubuntu_14.04_201601041324",
+  "base_url": "http://downloads.mesosphere.io/playa-mesos",
+  "hosts": {
+    "mesos-master": {
+      "ip": "10.141.141.10",
+      "vm_ram": "2048",
+      "vm_cpus": "2",
+      "external_volumes":true
+    }
+	}
+}
+```
+
+### Example Master with 3 Slaves and External Volumes
+Optionally a more realistic set of nodes can be deployed.  We include an
+example below for `mesos-master`, `mesos-slave1`, `mesos-slave2`, and
+`mesos-slave3`.  There is a `disable_slave` flag that can be set per node to
+determine the personality of the node which is used on `mesos-master`.  
+The root `vm_ram` and `vm_cpus` will be applied where configuration is not set
+on individual nodes.
+
+```json
+{
+  "platform": "virtualbox",
+  "box_name": "playa_mesos_ubuntu_14.04_201601041324",
+  "base_url": "http://downloads.mesosphere.io/playa-mesos",
+  "hosts": {
+    "mesos-master": {
+      "ip": "10.141.141.10",
+      "vm_ram": "512",
+      "vm_cpus": "1",
+      "disable_slave": true
+    },
+    "mesos-slave1":{
+      "ip":"10.141.141.11",
+      "external_volumes":true
+    },
+    "mesos-slave2":{
+      "ip":"10.141.141.12",
+      "external_volumes":true
+    },
+    "mesos-slave3":{
+      "ip":"10.141.141.13",
+      "external_volumes":true
+    }
+	},
+  "vm_ram": "1024",
+  "vm_cpus": "1"
+}
+```
+
+## Runtime Note
+At any time you can remove a host or add a new host with new
+settings.
+
+```bash
+vagrant destroy -f mesos-slave1 && vagrant up mesos-slave1
+```
+
 ## Quick Start
 
 1. [Install VirtualBox](https://www.virtualbox.org/wiki/Downloads)
 
 1. [Install Vagrant](http://www.vagrantup.com/downloads.html)
 
+1. (Optional for external volumes) Disable authentication for VirtualBox and start the SOAP Web Service.
+
+  ```bash
+  VBoxManage setproperty websrvauthlibrary null
+  /Applications/VirtualBox.app/Contents/MacOS/vboxwebsrv -H 0.0.0.0 -v
+  ```
+
 1. Clone this repository
 
   ```bash
-  git clone https://github.com/mesosphere/playa-mesos.git
+  git clone https://github.com/mesosphere/playa-mesos
   cd playa-mesos
   ```
 
@@ -47,7 +148,7 @@ VMware [Fusion](https://www.vmware.com/products/fusion/) or [Workstation](https:
 1. SSH to the VM
 
   ```bash
-  vagrant ssh
+  vagrant ssh mesos-master
   ps -eaf | grep mesos
   exit
   ```
@@ -104,6 +205,42 @@ The build is controlled with the following files:
 For additional information on customizing the build, or creating a new profile,
 see [Configuration][15] and the [Packer Documentation][20].
 
+## External Volume Examples
+There are two personalities being advertised from the external volume driver.
+The first is for native Docker volumes through the `docker` Volume Driver name.
+This is where a Docker containerizer is being used.
+
+```bash
+docker run -ti --volume-driver=docker -v test:/test busybox
+df /test
+exit
+```
+
+The second is through the Mesos containerizer through the `mesos` Volume Driver
+name.  See the following Marathon example `job.json` file.  
+
+```json
+{
+  "id": "hello-play",
+  "cmd": "while [ true ] ; do touch /tmp/hello ; sleep 5 ; done",
+  "mem": 32,
+  "cpus": 0.1,
+  "instances": 1,
+  "env": {
+    "DVDI_VOLUME_NAME": "test2",
+    "DVDI_VOLUME_DRIVER": "mesos",
+    "DVDI_VOLUME_OPTS": "size=5"
+  }
+}
+```
+
+Start the job interactively through Marathon.
+
+```bash
+vagrant ssh mesos-master
+http post http://127.0.0.1:8080/v2/apps < job.json
+```
+
 ## Documentation
 
 * [Configuration][15]
@@ -116,7 +253,7 @@ see [Configuration][15] and the [Packer Documentation][20].
 
 * [vagrant-mesos](https://github.com/everpeace/vagrant-mesos): Vagrant
   provisioning with multinode and EC2 support
-* [babushka-mesos](https://github.com/parolkar/mesos-babushka): It is [Babushka](http://babushka.me/) based provisioning of Mesos Cluster which can help you demonstrate [potential](http://vimeo.com/110914075) of mesos. 
+* [babushka-mesos](https://github.com/parolkar/mesos-babushka): It is [Babushka](http://babushka.me/) based provisioning of Mesos Cluster which can help you demonstrate [potential](http://vimeo.com/110914075) of mesos.
 
 ## Authors
 
@@ -146,3 +283,5 @@ VMware Support: [Fabio Rapposelli](https://github.com/frapposelli) ([@fabiorappo
 [21]: config.json "config.json"
 [22]: packer/packer.json "packer.json"
 [23]: lib/scripts "scripts"
+[24]: https://github.com/emccode/rexray "REX-Ray"
+[25]: https://github.com/emccode/mesos-module-dvdi "mesos-module-dvdi"