k8s-backup.sh

#!/bin/bash

set -euo pipefail

# Set backup output directory
TIMESTAMP=$(date +%Y%m%d-%H%M%S)
BACKUP_DIR="./k8s-backup-$TIMESTAMP"
GLOBAL_DIR="$BACKUP_DIR/__global"

mkdir -p "$BACKUP_DIR"
mkdir -p "$GLOBAL_DIR"

echo "🔄 Starting Kubernetes backup to $BACKUP_DIR..."

########################################
# Backup namespaced resources by namespace
########################################
namespaces=$(kubectl get ns -o jsonpath='{.items[*].metadata.name}')
namespaced_resources=$(kubectl api-resources --namespaced=true --verbs=list -o name)

for ns in $namespaces; do
    echo "📁 Backing up namespace: $ns"
    NS_DIR="$BACKUP_DIR/$ns"
    mkdir -p "$NS_DIR"

    for resource in $namespaced_resources; do
        items=$(kubectl get "$resource" -n "$ns" --no-headers --ignore-not-found -o custom-columns=NAME:.metadata.name || true)
        for item in $items; do
            echo "  🔹 $resource/$item"
            kubectl get "$resource" "$item" -n "$ns" -o yaml > "$NS_DIR/${resource//\//_}--${item}.yaml"
        done
    done
done

########################################
# Backup cluster-wide (non-namespaced) resources
########################################
global_resources=$(kubectl api-resources --namespaced=false --verbs=list -o name)

echo "🌐 Backing up cluster-wide resources..."
for resource in $global_resources; do
    items=$(kubectl get "$resource" --no-headers --ignore-not-found -o custom-columns=NAME:.metadata.name || true)
    for item in $items; do
        echo "  🌍 $resource/$item"
        kubectl get "$resource" "$item" -o yaml > "$GLOBAL_DIR/${resource//\//_}--${item}.yaml"
    done
done

echo "✅ Kubernetes cluster backup completed: $BACKUP_DIR"