gluster doc review feedbacks; fix Endpoints indexing

Signed-off-by: Huamin Chen <hchen@redhat.com>

examples/glusterfs/README.md

@@ -1,12 +1,12 @@
 ## Glusterfs
 
-[Glusterfs](http://www.gluster.org) is an open source scale-out filesystem. These examples provide information about how to allow Docker containers use Glusterfs volumes.
+[Glusterfs](http://www.gluster.org) is an open source scale-out filesystem. These examples provide information about how to allow containers use Glusterfs volumes.
 
-The example consists of a pod that runs on hosts that install Glusterfs client package.
+The example assumes that the Glusterfs client package is installed on all nodes.
 
 ### Prerequisites
 
-Install Glusterfs client package on the hosts.
+Install Glusterfs client package on the Kubernetes hosts.
 
 ### Create a POD
 
@@ -24,12 +24,14 @@ The following *volume* spec illustrates a sample configuration.
 }
 ```
 
-The parameters are explained as the followings. **endpoints** is endpoint name that defines Gluster service. **kubelet** is optimized to avoid mount storm, it will randomly pick one from the hosts to mount. If this host is unresponsive, the next host in the array is automatically selected. **path** is the Glusterfs volume name. **readOnly** is the boolean that sets the mountpoint readOnly or readWrite. **helper** can be a command that can be executed prior to mounting the filesystem.
+The parameters are explained as the followings. **endpoints** is endpoints name that represents a Gluster cluster configuration. **kubelet** is optimized to avoid mount storm, it will randomly pick one from the hosts to mount. If this host is unresponsive, the next Gluster host in the endpoints is automatically selected. **path** is the Glusterfs volume name. **readOnly** is the boolean that sets the mountpoint readOnly or readWrite. **helper** can be a command that can be executed prior to mounting the filesystem.
 
 Detailed POD and Gluster cluster endpoints examples can be found at [v1beta3/](v1beta3/) and [endpoints/](endpoints/)
 
 ```shell
+# create gluster cluster endpoints
 $ kubectl create -f examples/glusterfs/endpoints/glusterfs-endpoints.json
+# create a container using gluster volume
 $ kubectl create -f examples/glusterfs/v1beta3/glusterfs.json
 ```
 Once that's up you can list the pods and endpoint in the cluster, to verify that the master is running:

pkg/volume/glusterfs/glusterfs.go

@@ -201,20 +201,20 @@ func (glusterfsVolume *glusterfs) execMount(hosts *api.Endpoints, path string, m
 		opt = []string{"-o", "rw"}
 	}
 
-	l := len(hosts.Subsets[0].Addresses)
+	l := len(hosts.Subsets)
 	// avoid mount storm, pick a host randomly
 	start := rand.Int() % l
 	// iterate all hosts until mount succeeds.
 	for i := start; i < start+l; i++ {
 		if helper == "" {
-			arg := []string{"-t", "glusterfs", hosts.Subsets[0].Addresses[i%l].IP + ":" + path, mountpoint}
+			arg := []string{"-t", "glusterfs", hosts.Subsets[i%l].Addresses[0].IP + ":" + path, mountpoint}
 			mountArgs = append(arg, opt...)
 			glog.Infof("Glusterfs: mount cmd: mount %v", strings.Join(mountArgs, " "))
 			command = glusterfsVolume.exe.Command("mount", mountArgs...)
 		} else {
 			// if helper is provided, make a cmd like "helper_cmd helper_arg mount -t glusterfs mnt -o option"
 			helper_array := strings.Split(helper, " ")
-			arg := []string{"mount", "-t", "glusterfs", hosts.Subsets[0].Addresses[i%l].IP + ":" + path, mountpoint}
+			arg := []string{"mount", "-t", "glusterfs", hosts.Subsets[i%l].Addresses[0].IP + ":" + path, mountpoint}
 			mountArgs = append(arg, opt...)
 			args := append(helper_array[1:], mountArgs...)
 			glog.Infof("Glusterfs: mount cmd: %s %v", helper_array[0], strings.Join(args, " "))