**Kubernetes version**: 
1.6.1

**Environment**:
- **Cloud provider or hardware configuration**: 
Google container engine

- **OS**:
BUILD_ID=9000.104.0
NAME="Container-Optimized OS"
GOOGLE_CRASH_ID=Lakitu
VERSION_ID=56
BUG_REPORT_URL=https://crbug.com/new
PRETTY_NAME="Container-Optimized OS from Google"
VERSION=56
GOOGLE_METRICS_PRODUCT_ID=26
HOME_URL="https://cloud.google.com/compute/docs/containers/vm-image/"
ID=cos

- **Kernel**:
Linux gke-gup-kube-1-default-pool-1b1de7e8-3jh9 4.4.21+ #1 SMP Wed Apr 5 14:40:46 PDT 2017 x86_64 Intel(R) Xeon(R) CPU @ 2.30GHz GenuineIntel GNU/Linux

- **Install tools**:
Google Container engine

- **Others**:


**What happened**:
I am facing a problem when deploying Glusterfs + Heketi (thanks to [this excellent repo](https://github.com/gluster/gluster-kubernetes)) inside a GKE Kubernetes 1.6.1 cluster with nodes using the cos image. The gk-deploy script went well until it tries to execute heketi-cli -s http://${heketi_service} setup-openshift-heketi-storage that requires the dm_thin_pool module to be loaded.

The command fails with:
```
Error: Unable to execute command on glusterfs-xxxxx:   /usr/sbin/modprobe failed: 1
thin: Required device-mapper target(s) not detected in your kernel.
Run `lvcreate --help' for more information.
Failed on setup openshift heketi storage
```

The fix normally consists in using `modeprobe dm_thin_pool` to each Kubernetes node, But it won't work on the cos image type.

**What you expected to happen**:
We cannot use `modprobe dm_thin_pool` on the cos image as it will not find it, and there is no way to install new package to my knowledge. I would expect it to be included in cos image.

**How to reproduce it**:
ssh into one of the worker intances and `modprobe dm_thin_pool`

**Anything else we need to know**:
To be honest, I do not really know where is the best place to file this kind of issue related to cos image. My apologies if I am not choosing the right place. In this case, may you help me to choose a better one ?