00-testing-mnt-mount.md

Deploy Local storage provisioner

To test the issue with /mnt in kubelet in Lokomotive kinvolk-archives/lokomotive-kubernetes#160.

Add following flag to apiserver, kube-controller-manager, kube-scheduler

- --feature-gates=BlockVolume=true

Run following commands to edit the configs:

kubectl -n kube-system edit ds kube-apiserver
kubectl -n kube-system edit deploy kube-controller-manager
kubectl -n kube-system edit deploy kube-scheduler

And to add the flag to kubelet this is what you should add:

--feature-gates=BlockVolume=true \

Add that using following command:

kubectl -n kube-system edit ds kubelet

Create volumes on each host. By running following command:

sudo -i
mkdir /mnt/disks
for vol in vol1 vol2 vol3; do
    mkdir /mnt/disks/$vol
    mount -t tmpfs $vol /mnt/disks/$vol
done

Deploy the provisioner:

kubectl apply -f deployment/kubernetes/example/default_example_storageclass.yaml
kubectl create ns static-provisioner

Use following values file

common:
  namespace: static-provisioner
  podSecurityPolicy: true

classes:
- name: fast-disks # Defines name of storage classe.
  hostDir: /mnt/disks
  volumeMode: Filesystem
  fsType: tmpfs
  blockCleanerCommand:
     - "/scripts/shred.sh"
     - "2"

helm template --values custom-values.yaml ./helm/provisioner/ | k apply -f -

01-app.yaml

apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: privileged-psp-default
  namespace: default
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: privileged-psp
subjects:
- apiGroup: rbac.authorization.k8s.io
  kind: Group
  name: system:serviceaccounts:default
---
apiVersion: v1
kind: Service
metadata:
  name: nginx
  labels:
    app: nginx
spec:
  ports:
  - port: 80
    name: web
  clusterIP: None
  selector:
    app: nginx
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: web
spec:
  selector:
    matchLabels:
      app: nginx # has to match .spec.template.metadata.labels
  serviceName: "nginx"
  replicas: 3 # by default is 1
  template:
    metadata:
      labels:
        app: nginx # has to match .spec.selector.matchLabels
    spec:
      terminationGracePeriodSeconds: 10
      containers:
      - name: nginx
        image: k8s.gcr.io/nginx-slim:0.8
        ports:
        - containerPort: 80
          name: web
        volumeMounts:
        - name: www
          mountPath: /usr/share/nginx/html
  volumeClaimTemplates:
  - metadata:
      name: www
    spec:
      accessModes: [ "ReadWriteOnce" ]
      storageClassName: "fast-disks"
      resources:
        requests:
          storage: 1Gi