Pvc migration testing

Migrate many PVCs from one storage class to another in same namespace

Use these scripts for migration and testing

create-test-pvc.sh

#!/bin/bash
set -eu

NS=${1:-default}
SC=${2:-managed-csi-hdd}
PVC_NAME=test-pvc
POD_NAME=test-pod

cat <<EOF | kubectl apply -n $NS -f -
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: $PVC_NAME
spec:
  accessModes: [ReadWriteOnce]
  resources:
    requests:
      storage: 1Gi
EOF

cat <<EOF | kubectl apply -n $NS -f -
apiVersion: v1
kind: Pod
metadata:
  name: $POD_NAME
spec:
  containers:
  - name: busybox
    image: busybox
    command: ["sleep", "3600"]
    volumeMounts:
    - name: vol
      mountPath: /data
  volumes:
  - name: vol
    persistentVolumeClaim:
      claimName: $PVC_NAME
EOF

kubectl wait --for=condition=Ready pod/$POD_NAME -n $NS --timeout=60s
kubectl exec -n $NS $POD_NAME -- sh -c 'echo "This is a test." > /data/test.txt'

# kubectl delete pod/$POD_NAME pvc/$PVC_NAME -n $NS
kubectl delete pod/$POD_NAME -n $NS

swap-storage-class.sh

#!/bin/bash
set -euo pipefail

NS="${1:?Namespace required}"
SRC_SC="${2:?Source storage class required}"
DEST_SC="${3:?Destination storage class required}"
SINGLE_PVC="${4:-}" # optional fourth arg

get_matching_pvcs() {
  if [[ -n "$SINGLE_PVC" ]]; then
    size=$(kubectl get pvc "$SINGLE_PVC" -n "$NS" -o jsonpath='{.spec.resources.requests.storage}')
    sc=$(kubectl get pvc "$SINGLE_PVC" -n "$NS" -o jsonpath='{.spec.storageClassName}')
    if [[ "$sc" == "$SRC_SC" ]]; then
      echo "$SINGLE_PVC|$size"
    else
      echo "❌ PVC '$SINGLE_PVC' does not use storageClass '$SRC_SC'" >&2
      exit 1
    fi
  else
    kubectl get pvc -n "$NS" -o jsonpath='{range .items[*]}{.metadata.name}{"|"}{.spec.storageClassName}{"|"}{.spec.resources.requests.storage}{"\n"}{end}' |
      awk -F'|' -v sc="$SRC_SC" '$2==sc{print $1 "|" $3}'
  fi
}

pvcs=$(get_matching_pvcs)

if [[ -z "$pvcs" ]]; then
  echo "No matching PVCs found"
  exit 0
fi

for line in $pvcs; do
  pvc=$(cut -d'|' -f1 <<<"$line")
  size=$(cut -d'|' -f2 <<<"$line")
  tmp_pvc="${pvc}-tmp"

  echo "🔷 Scaling down workloads using PVC $pvc..."
  scaled_objects=()
  for obj in $(kubectl get deploy,sts -n "$NS" -o name); do
    if kubectl get "$obj" -n "$NS" -o json | grep -q "$pvc"; then
      echo "Scaling $obj to 0"
      kubectl scale "$obj" -n "$NS" --replicas=0
      scaled_objects+=("$obj")
    fi
  done

  echo "🔷 Creating temporary PVC $tmp_pvc with $DEST_SC..."
  cat <<EOF | kubectl apply -n "$NS" -f -
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: $tmp_pvc
spec:
  accessModes: [ReadWriteOnce]
  resources:
    requests:
      storage: $size
  storageClassName: $DEST_SC
EOF

  echo "🔷 Migrating data from $pvc -> $tmp_pvc..."
  pv-migrate \
    --source "$pvc" \
    -n "$NS" \
    --dest "$tmp_pvc" \
    -N "$NS" \
    --strategies mnt2,svc \
    --compress \
    --ignore-mounted

  echo "🔷 Deleting original PVC $pvc..."
  kubectl delete pvc "$pvc" -n "$NS"

  echo "🔷 Re-creating original PVC $pvc with $DEST_SC..."
  cat <<EOF | kubectl apply -n "$NS" -f -
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: $pvc
spec:
  accessModes: [ReadWriteOnce]
  resources:
    requests:
      storage: $size
  storageClassName: $DEST_SC
EOF

  echo "🔷 Migrating data back from $tmp_pvc -> $pvc..."
  pv-migrate \
    --source "$tmp_pvc" \
    -n "$NS" \
    --dest "$pvc" \
    -N "$NS" \
    --compress \
    --ignore-mounted

  echo "🔷 Deleting temporary PVC $tmp_pvc..."
  kubectl delete pvc "$tmp_pvc" -n "$NS"

  echo "🔷 Scaling workloads back up..."
  for obj in "${scaled_objects[@]}"; do
    echo "Scaling $obj to 1"
    kubectl scale "$obj" -n "$NS" --replicas=1
  done

  echo "✅ Migration of PVC $pvc complete."
done

example

./swap-storage-class.sh prometheus managed-csi-hdd standardssd-zrs prometheus-server

create-test-pod-and-mount.yaml

apiVersion: v1
kind: Pod
metadata:
  name: ubuntu-pvc-pod
spec:
  volumes:
    - name: my-pvc-storage
      persistentVolumeClaim:
        claimName: test-pvc # Replace with the name of your existing PVC
  containers:
    - name: ubuntu-container
      image: ubuntu:latest
      command: ["sleep", "infinity"]
      volumeMounts:
        - name: my-pvc-storage
          mountPath: /data # Replace with the desired mount path inside the container (e.g., /mnt/data)