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Migrate Files Between Kubernetes Volumes Using kubectl cp

Transfer files stored in Kubernetes Persistent Volumes from a source cluster to a target cluster using kubectl cp, routing through the local machine as an intermediary.

Prerequisites​

  • kubectl installed and configured with contexts for both clusters
  • Access to both clusters (kubeconfigs set up, e.g., via aws eks update-kubeconfig)
  • The source Pod name, namespace, and the path inside the Pod where files are stored
  • The target Pod name and namespace

Let's Start​

Step 1 — Configure kubectl access to both clusters​

Make sure you have kubeconfig entries for both clusters. For example:

aws eks update-kubeconfig --region us-east-1 --name source-cluster-name --profile source-profile
aws eks update-kubeconfig --region us-east-1 --name target-cluster-name --profile target-profile

Verify the contexts are available:

kubectl config get-contexts

Step 2 — Run the migration script​

Save the following script as transfer.sh, customize the variables at the top, and run it:

#!/bin/bash
set -euo pipefail

SOURCE_CONTEXT="source-context"      # kubectl context for the source cluster
TARGET_CONTEXT="target-context"      # kubectl context for the target cluster
SOURCE_POD="source-pod-name"
SOURCE_NAMESPACE="source-namespace"
SOURCE_PATH="/path/in/source-pod"

TARGET_POD="target-pod-name"
TARGET_NAMESPACE="target-namespace"
TARGET_PATH="/path/in/target-pod"

TEMP_LOCAL_DIR="/tmp/k8s-transfer"

# Validate both contexts exist
for ctx in "$SOURCE_CONTEXT" "$TARGET_CONTEXT"; do
  if ! kubectl config get-contexts "$ctx" &>/dev/null; then
    echo "Error: kubectl context '$ctx' not found" >&2
    exit 1
  fi
done

# Copy from source pod to local machine
echo "Copying files from $SOURCE_POD..."
mkdir -p $TEMP_LOCAL_DIR
kubectl --context="$SOURCE_CONTEXT" cp $SOURCE_NAMESPACE/$SOURCE_POD:$SOURCE_PATH $TEMP_LOCAL_DIR

# Copy from local machine to target pod
echo "Copying files to $TARGET_POD..."
kubectl --context="$TARGET_CONTEXT" cp $TEMP_LOCAL_DIR/. $TARGET_NAMESPACE/$TARGET_POD:$TARGET_PATH

# Clean up
rm -rf $TEMP_LOCAL_DIR
echo "Transfer complete."

Make it executable and run:

chmod +x transfer.sh
./transfer.sh
info

This approach works best for application assets — uploaded files, media, configuration — that are not part of a database. For database data, use the PostgreSQL dump restore guide instead.