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docs/tutorial/working-with-instancegroups.md

@@ -387,10 +387,10 @@ $ df -h | grep nvme[12]
 
 > Note: at present its up to the user ensure the correct device names.
 
-Some AWS instances provide multiple NVMe disks instead of a single device.  You can use an additionalUserData to create a RAID array from those disks
+Some AWS instances provide multiple NVMe disks instead of a single device. You can use an additionalUserData to create a RAID array from those disks
 and then use volumeMounts to mount and format that virtual device, for example:
 
-```
+```yaml
 apiVersion: kops.k8s.io/v1alpha2
 kind: InstanceGroup
 metadata:
@@ -405,7 +405,7 @@ spec:
         set -eo pipefail
         if ! [ -e /dev/md0 ] ; then
           DEVICES=($(lsblk -rp -I 259 -o NAME,MODEL | grep 'Amazon\\x20EC2\\x20NVMe' | cut -d ' ' -f 1))
-          DEVICE_COUNT=${#DEVICES[@]}
+          DEVICE_COUNT={{ "${#DEVICES[@]}" }}
           echo Found ${DEVICE_COUNT} NVMe disks: ${DEVICES[@]}
           if [[ $DEVICE_COUNT > 1 ]] ; then
             mdadm --create /dev/md0 --level=10 --raid-devices=${DEVICE_COUNT} ${DEVICES[@]}
@@ -417,7 +417,6 @@ spec:
     - device: /dev/md0
       filesystem: xfs
       path: /data
-
 ```
 
 ## Creating a new instance group