kube_pod_spec_volumes_persistentvolumeclaims only report the first PVC when there are more than one PVC mounted to the same Pod.

[yummydsky]

What happened: There are two volumes mounted on the same pod, but only the first volume can be found in kube-state-metrics.

kubectl get pvc -n influxdb
NAME                                         STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS   AGE
influxdb-data.pvc                 Bound    pvc-544ce610-d4f8-4ade-ade7-ea43046e4f1a   100Gi      RWO            local-path     351d
influxdb-log.pvc                  Bound    pvc-f1d0ced2-f717-4c7e-abdf-c69c978b7164   2Gi        RWO            local-path     351d

But in Prometheus

sum(kube_pod_spec_volumes_persistentvolumeclaims_info) by (pod, namespace, persistentvolumeclaim, volume)
{namespace="influx", persistentvolumeclaim="influxdb-data.pvc", pod="influxdb-0", volume="influxdb-data-storage"}

--

What you expected to happen:

The metric kube_pod_spec_volumes_persistentvolumeclaims_info can report all the volumes mounted information not just first one.

How to reproduce it (as minimally and precisely as possible):

Step 1. Create a pod with two persistent volume
Step 2. Check the kube-state-metrics kube_pod_spec_volumes_persistentvolumeclaims_info could report these two volumes or not.

Anything else we need to know?:

Environment:

• kube-state-metrics version: For all the kube-state-metrics versions. In my environment, the kube-state-metrics is v2.10.1
• Kubernetes version (use kubectl version):

  Client Version: version.Info{Major:"1", Minor:"21", GitVersion:"v1.21.1", GitCommit:"5e58841cce77d4bc13713ad2b91fa0d961e69192", GitTreeState:"clean", BuildDate:"2021-05-12T14:18:45Z", GoVersion:"go1.16.4", Compiler:"gc", Platform:"linux/amd64"}
  Server Version: version.Info{Major:"1", Minor:"21", GitVersion:"v1.21.1", GitCommit:"5e58841cce77d4bc13713ad2b91fa0d961e69192", GitTreeState:"clean", BuildDate:"2021-05-12T14:12:29Z", GoVersion:"go1.16.4", Compiler:"gc", Platform:"linux/amd64"}

• Cloud provider or hardware configuration:
• Other info:

[k8s-ci-robot]

This issue is currently awaiting triage.

If kube-state-metrics contributors determine this is a relevant issue, they will accept it by applying the triage/accepted label and provide further guidance.

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[ricardoapl]

Hello @yummydsky,

I can't reproduce your issue with either v2.10.1 or v2.12.0 (latest):

kube-state-metrics /metrics

kube_pod_spec_volumes_persistentvolumeclaims_info{namespace="default",pod="task-pv-pod",uid="317729a4-7dfa-4f53-8569-a3245e6a6e75",volume="task-pv-storage",persistentvolumeclaim="task-pv-claim"} 1
kube_pod_spec_volumes_persistentvolumeclaims_info{namespace="default",pod="task-pv-pod",uid="317729a4-7dfa-4f53-8569-a3245e6a6e75",volume="task-pv-storage-2",persistentvolumeclaim="task-pv-claim-2"} 1

PromQL

{namespace="default", persistentvolumeclaim="task-pv-claim", pod="task-pv-pod", volume="task-pv-storage"}
{namespace="default", persistentvolumeclaim="task-pv-claim-2", pod="task-pv-pod", volume="task-pv-storage-2"}

Kubernetes

Client Version: v1.30.1
Kustomize Version: v5.0.4-0.20230601165947-6ce0bf390ce3
Server Version: v1.30.0

Any chance you could try a more recent version of Kubernetes? v1.21 reached End of Life 2022-06-28 [1]

[1] https://kubernetes.io/releases/patch-releases/#support-period

[yummydsky]

@ricardoapl Thanks for the quick reply. Yes, you're right. This is not a bug. That's my fault. It's my pod template issue, I just requested the volume but did not mount it to a specific folder, so the metric works as expected.