fix wordpress tutorial pvcs

docs/tutorials/stateful-application/mysql-wordpress-persistent-volume.md

@@ -7,7 +7,7 @@ approvers:
 {% capture overview %}
 This tutorial shows you how to deploy a WordPress site and a MySQL database using Minikube. Both applications use PersistentVolumes and PersistentVolumeClaims to store data. 
 
-A [PersistentVolume](/docs/concepts/storage/persistent-volumes/) (PV) is a piece of storage in the cluster that has been provisioned by an administrator, and a [PersistentVolumeClaim](/docs/concepts/storage/persistent-volumes/#persistentvolumeclaims) (PVC) is a set amount of storage in a PV. PersistentVolumes and PersistentVolumeClaims are independent from Pod lifecycles and preserve data through restarting, rescheduling, and even deleting Pods. 
+A [PersistentVolume](/docs/concepts/storage/persistent-volumes/) (PV) is a piece of storage in the cluster that has been provisioned by an administrator, and a [PersistentVolumeClaim](/docs/concepts/storage/persistent-volumes/#persistentvolumeclaims) (PVC) is a set amount of storage in a PV. PersistentVolumes and PersistentVolumeClaims are independent from Pod lifecycles and preserve data through restarting, rescheduling, and even deleting Pods.  PersistentVolumes can be automatically provisioned by Kubernetes using a [StorageClass](/docs/concepts/storage/storage-classes/).
 
 **Warning:**  This deployment is not suitable for production use cases, as it uses single instance WordPress and MySQL Pods. Consider using [WordPress Helm Chart](https://github.com/kubernetes/charts/tree/master/stable/wordpress) to deploy WordPress in production.
 {: .warning}
@@ -18,7 +18,7 @@ A [PersistentVolume](/docs/concepts/storage/persistent-volumes/) (PV) is a piece
 {% endcapture %}
 
 {% capture objectives %}
-* Create a PersistentVolume
+* Create PersistentVolumeClaims and PersistentVolumes
 * Create a Secret
 * Deploy MySQL
 * Deploy WordPress
@@ -32,8 +32,6 @@ A [PersistentVolume](/docs/concepts/storage/persistent-volumes/) (PV) is a piece
 
 Download the following configuration files:
 
-1. [local-volumes.yaml](/docs/tutorials/stateful-application/mysql-wordpress-persistent-volume/local-volumes.yaml)
-
 1. [mysql-deployment.yaml](/docs/tutorials/stateful-application/mysql-wordpress-persistent-volume/mysql-deployment.yaml)
 
 1. [wordpress-deployment.yaml](/docs/tutorials/stateful-application/mysql-wordpress-persistent-volume/wordpress-deployment.yaml)
@@ -42,38 +40,22 @@ Download the following configuration files:
 
 {% capture lessoncontent %} 
 
-## Create a PersistentVolume
-
-MySQL and Wordpress each use a PersistentVolume to store data. While Kubernetes supports many different [types of PersistentVolumes](/docs/concepts/storage/persistent-volumes/#types-of-persistent-volumes), this tutorial covers [hostPath](/docs/concepts/storage/volumes/#hostpath).
+## Create PersistentVolumeClaims and PersistentVolumes
 
-**Note:** If you have a Kubernetes cluster running on Google Kubernetes Engine, please follow [this guide](https://cloud.google.com/kubernetes-engine/docs/tutorials/persistent-disk).
-{: .note}
+MySQL and Wordpress each require a PersistentVolume to store data.  Their PersistentVolumeClaims will be created at the deployment step.
 
-### Setting up a hostPath Volume
+Many cluster environments have a default StorageClass installed.  When a StorageClass is not specified in the PersistentVolumeClaim, the cluster's default StorageClass is used instead.
 
-A `hostPath` mounts a file or directory from the host node’s filesystem into your Pod. 
+When a PersistentVolumeClaim is created, a PersistentVolume is dynamically provisioned based on the StorageClass configuration.
 
-**Warning:** Only use `hostPath` for developing and testing. With hostPath, your data lives on the node the Pod is scheduled onto and does not move between nodes. If a Pod dies and gets scheduled to another node in the cluster, the data is lost. 
+**Warning:** In local clusters, the default StorageClass uses the `hostPath` provisioner.  `hostPath` volumes are only suitable for development and testing. With `hostPath` volumes, your data lives on the node the Pod is scheduled onto and does not move between nodes. If a Pod dies and gets scheduled to another node in the cluster, the data is lost.
 {: .warning}
 
-1. Launch a terminal window in the directory you downloaded the manifest files.
-
-2. Create two PersistentVolumes from the `local-volumes.yaml` file:
-
-       kubectl create -f local-volumes.yaml
-
-{% include code.html language="yaml" file="mysql-wordpress-persistent-volume/local-volumes.yaml" ghlink="/docs/tutorials/stateful-application/mysql-wordpress-persistent-volume/local-volumes.yaml" %}
-
-{:start="3"} 
-3. Run the following command to verify that two 20GiB PersistentVolumes are available:
-
-       kubectl get pv
-
-   The response should be like this:
+**Note:** If you are bringing up a cluster that needs to use the `hostPath` provisioner, the `--enable-hostpath-provisioner` flag must be set in the `controller-manager` component.
+{: .note}
 
-       NAME         CAPACITY   ACCESSMODES   RECLAIMPOLICY   STATUS      CLAIM     STORAGECLASS   REASON    AGE
-       local-pv-1   20Gi       RWO           Retain          Available                                      1m
-       local-pv-2   20Gi       RWO           Retain          Available                                      1m
+**Note:** If you have a Kubernetes cluster running on Google Kubernetes Engine, please follow [this guide](https://cloud.google.com/kubernetes-engine/docs/tutorials/persistent-disk).
+{: .note}
 
 ## Create a Secret for MySQL Password
 
@@ -108,7 +90,19 @@ The following manifest describes a single-instance MySQL Deployment. The MySQL c
 
        kubectl create -f mysql-deployment.yaml
 
-2. Verify that the Pod is running by running the following command:
+2. Verify that a PersistentVolume got dynamically provisioned:
+
+       kubectl get pvc
+
+   **Note:** It can take up to a few minutes for the PVs to be provisioned and bound.
+   {: .note}
+
+   The response should be like this:
+
+       NAME             STATUS    VOLUME                                     CAPACITY ACCESS MODES   STORAGECLASS   AGE
+       mysql-pv-claim   Bound     pvc-91e44fbf-d477-11e7-ac6a-42010a800002   20Gi     RWO            standard       29s
+
+3. Verify that the Pod is running by running the following command:
 
        kubectl get pods
 
@@ -130,7 +124,19 @@ The following manifest describes a single-instance WordPress Deployment and Serv
 
        kubectl create -f wordpress-deployment.yaml
 
-2. Verify that the Service is running by running the following command:
+2. Verify that a PersistentVolume got dynamically provisioned:
+
+       kubectl get pvc
+
+   **Note:** It can take up to a few minutes for the PVs to be provisioned and bound.
+   {: .note}
+
+   The response should be like this:
+
+       NAME             STATUS    VOLUME                                     CAPACITY ACCESS MODES   STORAGECLASS   AGE
+       wp-pv-claim      Bound     pvc-e69d834d-d477-11e7-ac6a-42010a800002   20Gi     RWO            standard       7s
+
+3. Verify that the Service is running by running the following command:
 
        kubectl get services wordpress
 
@@ -142,15 +148,15 @@ The following manifest describes a single-instance WordPress Deployment and Serv
    **Note:** Minikube can only expose Services through `NodePort`. <br/><br/>The `EXTERNAL-IP` is always `<pending>`.
    {: .note}
 
-3. Run the following command to get the IP Address for the WordPress Service:
+4. Run the following command to get the IP Address for the WordPress Service:
 
        minikube service wordpress --url
 
    The response should be like this:
 
        http://1.2.3.4:32406
 
-4. Copy the IP address, and load the page in your browser to view your site.
+5. Copy the IP address, and load the page in your browser to view your site.
 
    You should see the WordPress set up page similar to the following screenshot.
 
@@ -172,13 +178,9 @@ The following manifest describes a single-instance WordPress Deployment and Serv
        kubectl delete deployment -l app=wordpress
        kubectl delete service -l app=wordpress
 
-3. Run the following commands to delete the PersistentVolumeClaims and the PersistentVolumes:
+3. Run the following commands to delete the PersistentVolumeClaims.  The dynamically provisioned PersistentVolumes will be automatically deleted.
 
        kubectl delete pvc -l app=wordpress
-       kubectl delete pv local-pv-1 local-pv-2
-       
-   **Note:** Any other Type of PersistentVolume would allow you to recreate the Deployments and Services at this point without losing data, but `hostPath` loses the data as soon as the Pod stops running.
-   {: .note}         
 
 {% endcapture %}