fix(ci): gate USB e2e by Kubernetes version and fallback to default NFS storage class (#2307)

Description
Skip USB e2e specs on nested clusters that run Kubernetes versions below 1.34 by checking the actual API server version during the reusable CI pipeline. Also make NFS infra disks omit storageClassName when no storage class is explicitly set so the cluster default storage class can be used.

-------------

Signed-off-by: Nikita Korolev <nikita.korolev@flant.com>

Author: universal-itengineer

.github/workflows/e2e-reusable-pipeline.yml

@@ -1248,6 +1248,37 @@ jobs:
           echo "Download dependencies"
           go mod download
 
+      - name: Detect Kubernetes version for E2E
+        id: detect-k8s-version
+        run: |
+          set -euo pipefail
+
+          VERSION_JSON=$(kubectl version -o json)
+          SERVER_VERSION=$(echo "$VERSION_JSON" | jq -r '.serverVersion.gitVersion')
+          SERVER_MAJOR=$(echo "$VERSION_JSON" | jq -r '.serverVersion.major' | tr -cd '0-9')
+          SERVER_MINOR=$(echo "$VERSION_JSON" | jq -r '.serverVersion.minor' | tr -cd '0-9')
+
+          if [[ -z "$SERVER_MAJOR" || -z "$SERVER_MINOR" ]]; then
+            echo "[ERROR] Failed to parse Kubernetes server version: $SERVER_VERSION"
+            exit 1
+          fi
+
+          LABEL_FILTER=""
+          USB_SUPPORTED=false
+
+          if (( SERVER_MAJOR > 1 || (SERVER_MAJOR == 1 && SERVER_MINOR >= 34) )); then
+            USB_SUPPORTED=true
+            echo "[INFO] Kubernetes server version $SERVER_VERSION supports USB E2E tests"
+          else
+            LABEL_FILTER="!usb-precheck"
+            echo "[INFO] Kubernetes server version $SERVER_VERSION does not support USB E2E tests"
+            echo "[INFO] USB-labeled specs will be excluded with label filter: $LABEL_FILTER"
+          fi
+
+          echo "server-version=$SERVER_VERSION" >> "$GITHUB_OUTPUT"
+          echo "usb-supported=$USB_SUPPORTED" >> "$GITHUB_OUTPUT"
+          echo "label-filter=$LABEL_FILTER" >> "$GITHUB_OUTPUT"
+
       - name: Create vmclass for e2e tests
         run: |
           if ! (kubectl get vmclass generic-for-e2e 2>/dev/null); then
@@ -1270,6 +1301,9 @@ jobs:
           TIMEOUT: ${{ inputs.e2e_timeout }}
           CSI: ${{ inputs.storage_type }}
           STORAGE_CLASS_NAME: ${{ inputs.nested_storageclass_name }}
+          LABELS: ${{ steps.detect-k8s-version.outputs.label-filter }}
+          SERVER_K8S_VERSION: ${{ steps.detect-k8s-version.outputs.server-version }}
+          USB_SUPPORTED: ${{ steps.detect-k8s-version.outputs.usb-supported }}
         working-directory: ./test/e2e/
         run: |
           GINKGO_RESULT=$(mktemp -p $RUNNER_TEMP)
@@ -1278,25 +1312,36 @@ jobs:
           summary_file_name_junit="e2e_summary_${CSI}_${DATE}.xml"
           ginkgo_json_report="ginkgo_report_${CSI}_${DATE}.json"
           summary_file_name_json="e2e_summary_${CSI}_${DATE}.json"
+          FOCUS="${{ inputs.e2e_focus_tests }}"
 
           cp -a legacy/testdata /tmp/testdata
 
+          echo "[INFO] Kubernetes server version: ${SERVER_K8S_VERSION}"
+          echo "[INFO] USB E2E supported: ${USB_SUPPORTED}"
+          if [ -n "${LABELS:-}" ]; then
+            echo "[INFO] Applying Ginkgo label filter: ${LABELS}"
+          fi
+
           ./scripts/precheck-prepare_ci.sh
 
           set +e
-          FOCUS="${{ inputs.e2e_focus_tests }}"
+          GINKGO_ARGS=(
+            -v
+            --race
+            --timeout="$TIMEOUT"
+            --json-report="$ginkgo_json_report"
+            --junit-report="$summary_file_name_junit"
+          )
+
+          if [ -n "${LABELS:-}" ]; then
+            GINKGO_ARGS+=(--label-filter="$LABELS")
+          fi
+
           if [ -n "$FOCUS" ]; then
-            go tool ginkgo \
-              --focus="$FOCUS" \
-              -v --race --timeout=$TIMEOUT \
-              --json-report=$ginkgo_json_report \
-              --junit-report=$summary_file_name_junit | tee $GINKGO_RESULT
-          else
-            go tool ginkgo \
-              -v --race --timeout=$TIMEOUT \
-              --json-report=$ginkgo_json_report \
-              --junit-report=$summary_file_name_junit | tee $GINKGO_RESULT
+            GINKGO_ARGS+=(--focus="$FOCUS")
           fi
+
+          go tool ginkgo "${GINKGO_ARGS[@]}" | tee $GINKGO_RESULT
           GINKGO_EXIT_CODE=$?
           set -e
 

test/dvp-static-cluster/charts/infra/templates/nfs/vm.yaml

@@ -10,7 +10,9 @@ metadata:
 spec:
   persistentVolumeClaim:
     size: 150G
-    storageClassName: linstor-thin-r1
+    {{- if .Values.storageClass }}
+    storageClassName: {{ .Values.storageClass }}
+    {{- end }}
 ---
 apiVersion: virtualization.deckhouse.io/v1alpha2
 kind: VirtualDisk
@@ -26,7 +28,9 @@ spec:
     type: ContainerImage
   persistentVolumeClaim:
     size: 1Gi
-    storageClassName: linstor-thin-r1
+    {{- if .Values.storageClass }}
+    storageClassName: {{ .Values.storageClass }}
+    {{- end }}
 ---
 apiVersion: virtualization.deckhouse.io/v1alpha2
 kind: VirtualMachine
@@ -44,7 +48,7 @@ spec:
     name: nfs-vd-data
   bootloader: EFI
   cpu:
-    coreFraction: 20%
+    coreFraction: 50%
     cores: 1
   disruptions:
     restartApprovalMode: Automatic