Kubernetes with helm on local persistent volume with docker for Windows - kubernetes

Question

I tried to use helm on docker for windows on the local machine. When I used a storage class as local storage, persistent volume, and persistent volume claim without helm, it works fine. But when I used this setting with helm, CrashLoopBackOff happened.
localStrageClass.yaml
kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
name: local-storage
provisioner: kubernetes.io/no-provisioner
volumeBindingMode: WaitForFirstConsumer
pv.yaml
apiVersion: v1
kind: PersistentVolume
metadata:
name: local-pv002
labels:
type: local
spec:
capacity:
storage: 1Gi
accessModes:
- ReadWriteMany
#storageClassName: hostpath
mountOptions:
- hard
persistentVolumeReclaimPolicy: Delete
storageClassName: local-storage
local:
path: /c/k/share/mysql
nodeAffinity:
required:
nodeSelectorTerms:
- matchExpressions:
#- key: docker.io/hostname
- key: kubernetes.io/hostname
operator: In
values:
- docker-desktop
pvc.yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: local-mysql-claim
spec:
accessModes:
- ReadWriteMany
resources:
requests:
storage: 1Gi
storageClassName: local-storage
mysqlConf.yaml
persistence:
enabled: true
storageClass: local-storage
existingClaim: local-mysql-claim
accessMode: ReadWriteOnce
size: 1Gi
annotations: {}
$ helm install --name mysql stable/mysql -f mysqlConf.yaml
$ kubectl describe pod mysql
Containers:
mysql:
Container ID: docker://533e4569603b05fac83a0a701da97898b3190503618796678ac5db6340c4dce6
Image: mysql:5.7.14
Image ID: docker-pullable://mysql#sha256:c8f03238ca1783d25af320877f063a36dbfce0daa56a7b4955e6c6e05ab5c70b
Port: 3306/TCP
Host Port: 0/TCP
State: Waiting
Reason: CrashLoopBackOff
Last State: Terminated
Reason: Error
Exit Code: 1
Started: Thu, 28 Mar 2019 13:24:25 +0900
Finished: Thu, 28 Mar 2019 13:24:25 +0900
Ready: False
Restart Count: 2
Requests:
cpu: 100m
memory: 256Mi
Liveness: exec [sh -c mysqladmin ping -u root -p${MYSQL_ROOT_PASSWORD}] delay=30s timeout=5s period=10s #success=1 #failure=3
Readiness: exec [sh -c mysqladmin ping -u root -p${MYSQL_ROOT_PASSWORD}] delay=5s timeout=1s period=10s #success=1 #failure=3
Environment:
MYSQL_ROOT_PASSWORD: <set to the key 'mysql-root-password' in secret 'mysql'> Optional: false
MYSQL_PASSWORD: <set to the key 'mysql-password' in secret 'mysql'> Optional: true
MYSQL_USER:
MYSQL_DATABASE:
Mounts:
/var/lib/mysql from data (rw)
/var/run/secrets/kubernetes.io/serviceaccount from default-token-dccpv (ro)
Conditions:
Type Status
Initialized True
Ready False
ContainersReady False
PodScheduled True
Volumes:
data:
Type: PersistentVolumeClaim (a reference to a PersistentVolumeClaim in the same namespace)
ClaimName: local-mysql-claim
ReadOnly: false
default-token-dccpv:
Type: Secret (a volume populated by a Secret)
SecretName: default-token-dccpv
Optional: false
QoS Class: Burstable
Node-Selectors: <none>
Tolerations: node.kubernetes.io/not-ready:NoExecute for 300s
node.kubernetes.io/unreachable:NoExecute for 300s
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 39s default-scheduler Successfully assigned default/mysql-698897ff79-n768k to docker-desktop
Normal Pulled 38s kubelet, docker-desktop Container image "busybox:1.29.3" already present on machine
Normal Created 38s kubelet, docker-desktop Created container
Normal Started 38s kubelet, docker-desktop Started container
Normal Pulled 18s (x3 over 37s) kubelet, docker-desktop Container image "mysql:5.7.14" already present on machine
Normal Created 17s (x3 over 37s) kubelet, docker-desktop Created container
Normal Started 17s (x3 over 37s) kubelet, docker-desktop Started container
Warning BackOff 13s (x5 over 35s) kubelet, docker-desktop Back-off restarting failed container
When storageClassName was hostpath or did not used the configuration file as
$ helm install --name mysql stable/mysql
it worked fine.
Please tell me how to fix this problem.

Answer 1

I think you are having a mismatch of accessModes between what you claim in PVC definition (ReadWriteOnce) and what your Storage Class offers (ReadWriteMany).
Please mind also that PersistentVolume(s) of HostPath type does not support ReadWriteMany mode (see spec here).
I would propose you to create PV similar to this one:
# Create PV of manual StorageClass
kind: PersistentVolume
apiVersion: v1
metadata:
name: task-pv-volume
labels:
type: local
spec:
storageClassName: manual
capacity:
storage: 10Gi
accessModes:
- ReadWriteOnce
hostPath:
path: "/C/Users/K8S/mysql"
and override default PVC storageClassName configuration during helm install like this:
helm install --name my-sql stable/mysql --set persistence.storageClass=manual