Daemonset to automatically stripe all local ssd disks and mount for use in GKE workloads.

daemonset.yaml

---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: local-ssd-init
  labels:
    app: local-ssd-init
spec:
  template:
    spec:
      hostPID: true
      nodeSelector:
        cloud.google.com/gke-local-ssd: "true"
      volumes:
      - name: setup-script
        configMap:
          name: local-ssd-init
      - name: host-mount
        hostPath:
          path: /tmp/setup
      initContainers:
      - name: local-ssd-init
        image: marketplace.gcr.io/google/ubuntu1804
        securityContext:
          privileged: true
        volumeMounts:
        - name: setup-script
          mountPath: /tmp
        - name: host-mount
          mountPath: /host
        command:
          - /bin/bash
          - -c
          - |
            set -ex
            cp /tmp/setup.sh /tmp/wait.sh /host/
            /usr/bin/nsenter -m/proc/1/ns/mnt -- chmod u+x /tmp/setup/wait.sh /tmp/setup/setup.sh
            /usr/bin/nsenter -m/proc/1/ns/mnt /bin/bash /tmp/setup/wait.sh
            /usr/bin/nsenter -m/proc/1/ns/mnt /bin/bash /tmp/setup/setup.sh
      containers:
      - image: "gcr.io/google-containers/pause:2.0"
        name: pause

kustomization.yaml

apiVersion: kustomize.config.k8s.io/v1beta1
kind: Kustomization
namespace: kube-system

commonLabels:
  app.kubernetes.io/name: local-ssd-init

resources:
- daemonset.yaml

configMapGenerator:
- name: local-ssd-init
  files:
  - setup.sh
  - wait.sh

setup.sh

#!/bin/bash
set -exo pipefail

isMounted() { findmnt -rno SOURCE,TARGET "$1" >/dev/null; }

SSDS=(`readlink -f /dev/disk/by-id/google-local-ssd-*`)

apt-get -y update && apt-get -y install mdadm xfsprogs --no-install-recommends

if [ -b "/dev/md0" ]; then
  if isMounted "/dev/md0"; then
    echo "Array already created and mounted. Exiting"
    exit 0
  fi
  mdadm --stop /dev/md0
  mdadm --zero-superblock "${SSDS[@]}"
fi

umount "${SSDS[@]}" 2>/dev/null || true

yes | mdadm --create /dev/md0 --force --level=0 "--raid-devices=${#SSDS[@]}" "${SSDS[@]}" || true
mkfs.xfs -f /dev/md0

mkdir -p /mnt/disks/ssd
mount /dev/md0 /mnt/disks/ssd

# This file can be used as a Volume to ensure only a prepared host will allow pods to be scheduled on it.
touch /mnt/disks/ssd/.initialized

wait.sh

#!/bin/bash
while sudo fuser /var/{lib/{dpkg,apt/lists},cache/apt/archives}/lock >/dev/null 2>&1; do sleep 1; done