Handling PersistentVolumeClaim in DaemonSet - kubernetes

Question

I have a DaemonSet that creates flink task manager pods, one per each node.
Nodes
Say I have two nodes
node-A
node-B
Pods
the daemonSet would create
pod-A on node-A
pod-B on node-B
Persistent Volume Claim
I am on AKS and want to use azure-disk for Persistent Storage
According to the docs : [https://learn.microsoft.com/en-us/azure/aks/azure-disks-dynamic-pv ]
an azure disk can be associated on to single node
say I create
pvc-A for pv-A attached to node-A
pvc-B for pv-B attached to node-B
Question
How can I associate pod-A on node-A to use pcv-A ?
UPDATE:
After much googling, i stumbled upon that it might be better/cleaner to use a StatefulSet instead. This does mean that you won't get the features available to you via DaemonSet like one pod per node.
https://medium.com/#zhimin.wen/persistent-volume-claim-for-statefulset-8050e396cc51

Answer 1

If you use a persistentVolumeClaim in your daemonset definition, and the persistentVolumeClaim is satisfied with PV with the type of hostPath, your daemon pods will read and write to the local path defined by hostPath. This behavior will help you separate the storage using one PVC.
This might not directly apply to your situation but I hope this helps whoever searching for something like a "volumeClaimTemplate for DaemonSet" in the future.
Using the same example as cookiedough (thank you!)
apiVersion: apps/v1
kind: DaemonSet
metadata:
name: x
namespace: x
labels:
k8s-app: x
spec:
selector:
matchLabels:
name: x
template:
metadata:
labels:
name: x
spec:
...
containers:
- name: x
...
volumeMounts:
- name: volume
mountPath: /var/log
volumes:
- name: volume
persistentVolumeClaim:
claimName: my-pvc
And that PVC is bound to a PV (Note that there is only one PVC and one PV!)
apiVersion: v1
kind: PersistentVolume
metadata:
creationTimestamp: null
labels:
type: local
name: mem
spec:
accessModes:
- ReadWriteOnce
capacity:
storage: 1Gi
hostPath:
path: /tmp/mem
type: Directory
storageClassName: standard
status: {}
Your daemon pods will actually use /tmp/mem on each node. (There's at most 1 daemon pod on each node so that's fine.)

Answer 2

The way to attach a PVC to your DaemonSet pod is not any different than how you do it with other types of pods. Create your PVC and mount it as a volume onto the pod.
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
name: my-pvc
namespace: x
spec:
accessModes:
- ReadWriteOnce
resources:
requests:
storage: 10Gi
This is what the DaemonSet manifest would look like:
apiVersion: apps/v1
kind: DaemonSet
metadata:
name: x
namespace: x
labels:
k8s-app: x
spec:
selector:
matchLabels:
name: x
template:
metadata:
labels:
name: x
spec:
...
containers:
- name: x
...
volumeMounts:
- name: volume
mountPath: /var/log
volumes:
- name: volume
persistentVolumeClaim:
claimName: my-pvc