Persistent volume to windows not working on kubernetes - kubernetes

I have map windows folder into me linux machine with
mount -t cifs //AUTOCHECK/OneStopShopWebAPI -o user=someuser,password=Aa1234 /xml_shared
and the following command
df -hk
give me
//AUTOCHECK/OneStopShopWebAPI 83372028 58363852 25008176 71% /xml_shared
after that I create yaml file with
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: pvc-nfs-jenkins-slave
spec:
storageClassName: jenkins-slave-data
accessModes:
- ReadWriteMany
resources:
requests:
storage: 4Gi
---
apiVersion: v1
kind: PersistentVolume
metadata:
name: pv-nfs-jenkins-slave
labels:
type: jenkins-slave-data2
spec:
storageClassName: jenkins-slave-data
capacity:
storage: 4Gi
accessModes:
- ReadWriteMany
nfs:
server: 192.168.100.109
path: "//AUTOCHECK/OneStopShopWebAPI/jenkins_slave_shared"
this seems to not work when I create new pod
apiVersion: v1
kind: Pod
metadata:
name: jenkins-slave
labels:
label: jenkins-slave
spec:
containers:
- name: node
image: node
command:
- cat
tty: true
volumeMounts:
- mountPath: /var/jenkins_slave_shared
name: jenkins-slave-vol
volumes:
- name: jenkins-slave-vol
persistentVolumeClaim:
claimName: pvc-nfs-jenkins-slave
do i need to change the nfs ? what is wrong with me logic?

The mounting of CIFS share under Linux machine is correct but you need to take different approach to mount CIFS volume under Kubernetes. Let me explain:
There are some differences between NFS and CIFS.
This site explained the whole process step by step: Github CIFS Kubernetes.

Related

How to mount a ceph-csi provisioned block-volume?

I have a PVC like below:
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: raw-block-pvc
spec:
accessModes:
- ReadWriteOnce
volumeMode: Block
resources:
requests:
storage: 1Gi
storageClassName: csi-rbd-sc
It is provisioned by ceph-csi plugin. As you can see, it will perform as a block device in a Pod. And the Pod definition is like this:
---
apiVersion: v1
kind: Pod
metadata:
name: pod-with-raw-block-volume
spec:
containers:
- name: fc-container
image: nginx
volumeDevices:
- name: data
devicePath: /dev/xvda
volumes:
- name: data
persistentVolumeClaim:
claimName: raw-block-pvc
I can find it at /dev/xvda.
But when I try to mount it on a dir by mount /dev/xvda /mnt, it failed and showed following:
mount: /mnt: cannot mount /dev/xvda read-only.
Could anyone tell me what is the reason?
When you claim volumeMode as block in pvc , that's a raw block device, /dev/xvda is block device same as your linux hard disk. You can't mount one raw block device, it's not formatted , no file system on it.
If you want to attache storage to directory, you cloud claim filesystem volumemode.
here is a sample, more detail you could visit https://docs.ceph.com/en/latest/rbd/rbd-kubernetes/
$ cat <<EOF > pvc.yaml
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: rbd-pvc
spec:
accessModes:
- ReadWriteOnce
volumeMode: Filesystem
resources:
requests:
storage: 1Gi
storageClassName: csi-rbd-sc
EOF
$ kubectl apply -f pvc.yaml
$ cat <<EOF > pod.yaml
---
apiVersion: v1
kind: Pod
metadata:
name: csi-rbd-demo-pod
spec:
containers:
- name: web-server
image: nginx
volumeMounts:
- name: mypvc
mountPath: /var/lib/www/html
volumes:
- name: mypvc
persistentVolumeClaim:
claimName: rbd-pvc
readOnly: false
EOF
$ kubectl apply -f pod.yaml

Create a Kubernetes Persistent Volume on GKE connected to an external NFS server on GCE

I have a NFS server running on a VM in GCE. The NFS server /etc/exports file is already configured to allow mounting by the K8s cluster. I attempted to create a Persistent Volume (PV) and Persistent Volume Claim (PVC) and I added spec.containers.volumeMounts and spec.volumes entries. Basically, Google provisions a new disk instead of connecting to the NFS server.
In the deployments file I have added:
volumeMounts:
- name: nfs-pvc-data
mountPath: "/mnt/nfs"
volumes:
- name: nfs-pvc-data
persistentVolumeClaim:
claimName: nfs-pvc
nfs-pv.yaml
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-pv
namespace: comms
labels:
volume: nfs-pv
spec:
capacity:
storage: 10G
#volumeMode: Filesystem
accessModes:
- ReadOnlyMany
mountOptions:
- hard
- nfsvers=4.2
nfs:
path: /
server: 10.xxx.xx.xx
readOnly: false
nfs-pvc.yaml
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: nfs-pvc
namespace: comms
#spec: # The PVC is stuck on ready as long as spec.selector exists in the yaml
#selector:
#matchLabels:
#volume: nfs-pv
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 1G
I was able to mount the NFS server external to the Kubernetes cluster using the following PV and PVC YAML.
apiVersion: v1
kind: PersistentVolume
metadata:
name: gce-nfs
namespace: comms
spec:
capacity:
storage: 1Mi
accessModes:
- ReadWriteMany
nfs:
server: 10.xxx.xxx.xxx
path: "/"
---
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: gce-nfs
spec:
accessModes:
- ReadWriteMany
storageClassName: ""
resources:
requests:
storage: 1Mi
Then in the deployment YAML I added the following to the containers section:
volumeMounts:
- name: nfs-pvc-data
mountPath: "/mnt/nfs"
volumes:
- name: nfs-pvc-data
persistentVolumeClaim:
claimName: gce-nfs
The pod/container will boot connected to the external NFS server.

How to have multiple pods access an existing NFS folder in Kubernetes?

I have a folder of TFRecords on a network that I want to expose to multiple pods. The folder has been exported via NFS.
I have tried creating a Persistent Volume, followed by a Persistent Volume Claim. However, that just creates a folder inside the NFS mount, which I don't want. Instead, I want to Pod to access the folder with the TFRecords.
I have listed the manifests for the PV and PVC.
apiVersion: v1
kind: PersistentVolume
metadata:
name: nfs-tfrecord-pv
spec:
capacity:
storage: 30Gi
accessModes:
- ReadWriteMany
persistentVolumeReclaimPolicy: Retain
nfs:
path: /media/veracrypt1/
server: 1.2.3.4
readOnly: false
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
name: nfs-tfrecord-pvc
namespace: default
spec:
accessModes:
- ReadWriteMany
storageClassName: nfs-tfrecord
resources:
requests:
storage: 1Gi
I figured it out. The issue was I was looking at the problem the wrong way. I didn't need any provisioning. Instead, what was need was to simply mount the NFS volume within the container:
kind: Pod
apiVersion: v1
metadata:
name: pod-using-nfs
spec:
containers:
- name: app
image: alpine
volumeMounts:
- name: data
mountPath: /mnt/data
command: ["/bin/sh"]
args: ["-c", "sleep 500000"]
volumes:
- name: data
nfs:
server: 1.2.3.4
path: /media/foo/DATA

Creating a NFS sidecar for Kubernetes

I am trying to create a NFS sidecar for Kubernetes. The goal is to be able to mount an NFS volume to an existing pod without affecting performance. At the same time, I want to be able to mount the same NFS volume onto another pod or server (read-only perhaps) in order to view the content there. Has anyone tried this? Do anyone have the procedure?
Rather than use a sidecar I would suggest using a PersistentVolume which uses the NFS driver and PersistentVolumeClaim. If you use the RWX/ReadWriteMany access mode, you'll be able to mount the share into multiple pods.
For examplen the pv:
kind: PersistentVolume
apiVersion: v1
metadata:
name: mypv
spec:
capacity:
storage: 2Gi
nfs:
server: my.nfs.server
path: /myshare
accessModes:
- ReadWriteMany
persistentVolumeReclaimPolicy: Recycle
the pvc:
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: myclaim
spec:
accessModes:
- ReadWriteMany
resources:
requests:
storage: 2Gi
and mounted in a pod:
apiVersion: v1
kind: Pod
metadata:
name: mypod
spec:
containers:
- name: myfrontend
image: nginx
volumeMounts:
- mountPath: "/var/www/html"
name: mypd
volumes:
- name: mypd
persistentVolumeClaim:
claimName: myclaim
Kubernetes Docs on Persistent Volumes

kubernetes persistence volume and persistence volume claim exceeded storage

By following kubernetes guide i have created a pv, pvc and pod. i have claimed only 10Mi of out of 20Mi pv. I have copied 23Mi that is more than my pv. But my pod is still running. Can any one explain ?
pv-volume.yaml
kind: PersistentVolume
apiVersion: v1
metadata:
name: task-pv-volume
labels:
type: local
spec:
storageClassName: manual
capacity:
storage: 20Mi
accessModes:
- ReadWriteOnce
hostPath:
path: "/mnt/data"
pv-claim.yaml
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: task-pv-claim
spec:
storageClassName: manual
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 10Mi
pv-pod.yaml
kind: Pod
apiVersion: v1
metadata:
name: task-pv-pod
spec:
volumes:
- name: task-pv-storage
persistentVolumeClaim:
claimName: task-pv-claim
containers:
- name: task-pv-container
image: nginx
ports:
- containerPort: 80
name: "http-server"
volumeMounts:
- mountPath: "/usr/share/nginx/html"
name: task-pv-storage
Probably you can copy as much data into shared storage /mnt/data (on your active node) using any of applied POD's storages ,/usr/share/nginx/html, shared between node and pods till your node will stop responding.
In case you need to test this scenario in more real conditions could you please consider create NFS persistent storage using GlusterFS, nfs-utils, or mount a raw partition file made with dd.
In Minikube nodes are using ephemeral-storages. Detailed information about node/pod resources you can find here:
https://kubernetes.io/docs/tasks/administer-cluster/reserve-compute-resources/#node-allocatable
Hope this help.