Creates a Pod, mounts a StatefulSet's PV to the pod, copies config files to it, deletes the pod, and releases the claim so the StatefulSet can regain its use.

k8s_copy_files.sh

#!/usr/bin/env bash

remove_claim() {
    pvc=$(export name="$1" && kubectl get pv --no-headers | awk -v name="$name" '$0~name {print $1}')
    kubectl patch pv $pvc --type json -p '[{"op": "remove", "path": "/spec/claimRef"}]'
}

if [ -n $2 ]; then
  namespace=$2
else
  namespace=$1
fi

cat << EOF > $1.yaml
apiVersion: v1
kind: Pod
metadata:
  name: dataaccess
  namespace: $namespace
spec:
  containers:
  - name: alpine
    image: alpine:latest
    imagePullPolicy: IfNotPresent
    command: ['sleep', 'infinity']
    volumeMounts:
    - name: $1-config-pvc
      mountPath: /config
  volumes:
    - name: $1-config-pvc
      persistentVolumeClaim:
        claimName: $1-config-$1-0
EOF
echo "Scaling $1 down..."
kubectl scale statefulset -n $namespace $1 --replicas=0
echo "Removing claimRef from PVC..."
remove_claim $1
echo "Sleeping 10 seconds..."
sleep 10
echo "Creating a temporary pod to copy to $1..."
kubectl apply -f $1.yaml
echo "Sleeping 20 seconds to allow the temporary pod to come up..."
sleep 20
echo "Copying files to $1..."
ssh dkr "./kubectl cp --kubeconfig ./config ~/@data/$1/config $namespace/dataaccess:/"
echo "Deleting temporary pod..."
kubectl delete -f $1.yaml
rm $1.yaml
echo "Removing claimRef from PVC..."
remove_claim $1
echo "Sleeping 10 seconds..."
sleep 10
echo "Scaling $1 back up..."
kubectl scale statefulset -n $namespace $1 --replicas=1
echo "Done!"