Resize PersistentVolumeClaims according to owning StatefulSet spec

resize-pvc.sh

#!/bin/sh -eu

# Update the actual storage requets of existing PVCs to those specified in their owning StatefulSet.
# This assumes the StatefulSet was already "updated" (via `kubectl replace --force --cascade=orphan` or similar)

STS="$1"

kubectl get statefulset "$STS" -o jsonpath='{range .spec.volumeClaimTemplates[]}{.metadata.name} {.spec.resources.requests.storage}{"\n"}{end}' |
    while read -r VOLNAME SIZE; do
        for PVC in $(kubectl get pvc -o custom-columns=NAME:.metadata.name | grep -E "^$VOLNAME-$STS-[0-9]+\$"); do
            kubectl patch pvc "$PVC" -p '{"spec": {"resources": {"requests": {"storage": "'"$SIZE"'"}}}}' > /dev/null
        done
    done