wrote this utility to copy AWS tags from EC2 instances to the EBS volumes they mount

ebs_tagger.go

package main

import (
	"fmt"
	"log"
	"time"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/ec2"
)

type tag struct {
	Key   string
	Value string
}

func main() {
	for _, r := range []string{"us-east-1", "us-west-1"} {
		tagVolumesInRegion(r)
	}
}

func tagVolumesInRegion(r string) {
	svc := ec2.New(session.New(), &aws.Config{Region: aws.String(r)})

	err := svc.DescribeInstancesPages(nil, func(page *ec2.DescribeInstancesOutput, lastPage bool) bool {
		for _, r := range page.Reservations {
			for _, i := range r.Instances {
				var tags []tag
				for _, t := range i.Tags {
					if *t.Key == "Environment" || *t.Key == "CC" {
						ts := tag{Key: *t.Key, Value: *t.Value}
						tags = append(tags, ts)
					}
				}

				if len(tags) == 0 {
					fmt.Printf("[%s] in region %s has no CC or Environment tags\n", *i.InstanceId, r)
					continue
				}

				for _, v := range i.BlockDeviceMappings {
					var tagsToAdd []*ec2.Tag

					for _, t := range tags {
						tagsToAdd = append(tagsToAdd, &ec2.Tag{Key: aws.String(t.Key), Value: aws.String(t.Value)})
					}

					fmt.Printf("adding tags %s to volume %s.........", tags, *v.Ebs.VolumeId)
					resp, err := svc.CreateTags(&ec2.CreateTagsInput{
						Resources: []*string{
							aws.String(*v.Ebs.VolumeId),
						},
						Tags: tagsToAdd,
						// DryRun: aws.Bool(true),
					})

					if err != nil {
						fmt.Println("failure in CreateTags", err)
						fmt.Println(resp)
					}
					fmt.Printf("DONE\n")
					time.Sleep(500 * time.Millisecond) // to keep under rate limit
				}
			}
		}
		return lastPage == false
	})

	if err != nil {
		log.Fatal(err)
	}
}