How do you mount volumes on Dask workers with dask-kubernetes? - azure-storage-files

Question

I used the following code to create a cluster
from dask_kubernetes import KubeCluster
cluster = KubeCluster.from_yaml('worker.yaml')
cluster.adapt(minimum=1, maximum=10)
with the following yaml code (worker.yaml):
kind: Pod
metadata:
labels:
foo: bar
spec:
restartPolicy: Never
containers:
- image: daskdev/dask:latest
imagePullPolicy: IfNotPresent
args: [dask-worker, --nthreads, '4', --no-bokeh, --memory-limit, 3GB, --death-timeout, '300']
name: dask
resources:
limits:
cpu: "4"
memory: 3G
requests:
cpu: "2"
memory: 2G
This worked as expected. Now I added a volume mount as shown
kind: Pod
metadata:
labels:
foo: bar
spec:
restartPolicy: Never
containers:
- image: daskdev/dask:latest
imagePullPolicy: IfNotPresent
args: [dask-worker, --nthreads, '4', --no-bokeh, --memory-limit, 3GB, --death-timeout, '300']
name: dask
resources:
limits:
cpu: "4"
memory: 3G
requests:
cpu: "2"
memory: 2G
volumeMounts:
- name: somedata
mountPath: /opt/some/data
volumes:
- name: somedata
azureFile:
secretName: azure-secret
shareName: somedata
readOnly: true
I don't see the volume getting mounted. But when I simply run
kubectl create -f worker.yaml
I can see the volume getting mounted.
Does KubeCluster support volume mounts? And if so how do you configure them?

Answer 1

I am unable to reproduce your issue when testing with a HostPath volume.
from dask_kubernetes import KubeCluster
cluster = KubeCluster.from_yaml('worker.yaml')
cluster.adapt(minimum=1, maximum=10)
# worker.yaml
kind: Pod
metadata:
labels:
foo: bar
spec:
restartPolicy: Never
containers:
- image: daskdev/dask:latest
imagePullPolicy: IfNotPresent
args: [dask-worker, --nthreads, '4', --no-bokeh, --memory-limit, 3GB, --death-timeout, '300']
name: dask
resources:
limits:
cpu: "4"
memory: 3G
requests:
cpu: "2"
memory: 2G
volumeMounts:
- name: somedata
mountPath: /opt/some/data
volumes:
- name: somedata
hostPath:
path: /tmp/data
type: Directory
If I run kubectl describe po <podname> for the worker that is created I can see the volume created successfully.
Volumes:
somedata:
Type: HostPath (bare host directory volume)
Path: /tmp/data
HostPathType: Directory
And it is mounted where I would expect.
Mounts:
/opt/some/data from somedata (rw)
Also if I create a shell into the container with kubectl exec -it <podname> bash and ls /opt/some/data I can see files that I create in the host path.
Therefore volumes work with KubeCluster, so if you are experiencing issues with the azureFile storage then there must be some configuration issue with your Kubernetes cluster.