apiVersion: v1
kind: Pod
metadata:
  name: k8s-discovery-test
  namespace: redis-demo
spec:
  containers:
  - name: test
    image: alpine:latest
    command: ["sh", "-c"]
    args:
    - |
      echo "=== Installing Go ==="
      apk add --no-cache go
      
      echo "=== Building discovery tool ==="
      mkdir -p /app/discovery
      cat > /app/discovery/main.go << 'EOF'
package main

import (
	"fmt"
	"net"
	"strings"
)

func main() {
	fmt.Println("=== Kubernetes Service Discovery Test ===")
	
	headlessAddr := "redis-headless.redis-demo.svc.cluster.local"
	fmt.Printf("🔍 Discovering service: %s\n", headlessAddr)
	
	serviceInfo, err := parseHeadlessServiceAddr(headlessAddr)
	if err != nil {
		fmt.Printf("❌ Failed to discover service: %v\n", err)
		return
	}
	
	fmt.Println("\n📋 Service Information:")
	fmt.Printf("  Name: %s\n", serviceInfo.Name)
	fmt.Printf("  Namespace: %s\n", serviceInfo.Namespace)
	
	if len(serviceInfo.All) > 0 {
		fmt.Printf("\n🌐 All Pod IPs (%d):\n", len(serviceInfo.All))
		for idx, ip := range serviceInfo.All {
			podName := fmt.Sprintf("%s-%d", serviceInfo.Name, idx)
			if idx == 0 {
				fmt.Printf("  📌 Master:  %s -> %s\n", podName, ip)
			} else {
				fmt.Printf("  📊 Replica: %s -> %s\n", podName, ip)
			}
		}
	}
	
	fmt.Println("\n🎉 Service discovery completed successfully!")
}

type ServiceInfo struct {
	Name  string
	All   []string
}

func parseHeadlessServiceAddr(headlessAddr string) (*ServiceInfo, error) {
	resolver := &net.Resolver{PreferGo: true}
	addrs, err := resolver.LookupIPAddr(headlessAddr)
	if err != nil {
		return nil, fmt.Errorf("DNS query failed: %v", err)
	}
	
	if len(addrs) == 0 {
		return nil, fmt.Errorf("no records found")
	}
	
	var podIPs []string
	for _, addr := range addrs {
		podIPs = append(podIPs, addr.String())
	}
	
	parts := strings.Split(headlessAddr, ".")
	if len(parts) < 4 {
		return nil, fmt.Errorf("invalid format")
	}
	
	serviceName := parts[0]
	namespace := parts[1]
	
	return &ServiceInfo{
		Name: serviceName,
		All:  podIPs,
	}, nil
}
EOF
      
      echo "=== Running discovery tool ==="
      cd /app/discovery && go run main.go
      
      echo "=== Sleeping for 30s ==="
      sleep 30
    volumeMounts:
    - name: app-volume
      mountPath: /app
  volumes:
  - name: app-volume
    emptyDir: {}
  restartPolicy: Never