Getting ALB arn from TargetGroup Arn

gettg.go

package main

import (
	"context"
	"fmt"
	"log"
	"os"

	"github.com/aws/aws-sdk-go-v2/config"
	elbv2 "github.com/aws/aws-sdk-go-v2/service/elasticloadbalancingv2"
)

func main() {

	if len(os.Args) < 2 {
		fmt.Printf("Usage: %v <listenerArn>", os.Args[0])
		os.Exit(1)
	}

	tgArn := os.Args[1]

	ctx := context.Background()

	cfg, err := config.LoadDefaultConfig(context.Background())
	if err != nil {
		log.Fatalf("unable to load SDK config, %v", err)
	}
	svc := elbv2.NewFromConfig(cfg)
	searchInput := &elbv2.DescribeTargetGroupsInput{TargetGroupArns: []string{tgArn}}
	rulesOutput, err := svc.DescribeTargetGroups(ctx, searchInput)
	if err != nil {
		log.Fatalf("failed to run describe target group: %v", err)
	}

	for _, tg := range rulesOutput.TargetGroups {
		fmt.Printf("TargetGroupArn: %v -> LoadBalancer %v\n", *tg.TargetGroupArn, tg.LoadBalancerArns)
	}
}