terraform/builtin/providers/aws/tags_route53.go

package aws

import (
	"log"

	"github.com/hashicorp/aws-sdk-go/aws"
	"github.com/hashicorp/aws-sdk-go/gen/route53"
	"github.com/hashicorp/terraform/helper/schema"
)

// setTags is a helper to set the tags for a resource. It expects the
// tags field to be named "tags"
func setTagsR53(conn *route53.Route53, d *schema.ResourceData) error {
	if d.HasChange("tags") {
		oraw, nraw := d.GetChange("tags")
		o := oraw.(map[string]interface{})
		n := nraw.(map[string]interface{})
		create, remove := diffTagsR53(tagsFromMapR53(o), tagsFromMapR53(n))

		// Set tags
		r := make([]string, len(remove))
		for i, t := range remove {
			r[i] = *t.Key
		}
		log.Printf("[DEBUG] Changing tags: \n\tadding: %#v\n\tremoving:%#v", create, remove)
		req := &route53.ChangeTagsForResourceRequest{
			AddTags:       create,
			RemoveTagKeys: r,
			ResourceID:    aws.String(d.Id()),
			ResourceType:  aws.String("hostedzone"),
		}

		_, err := conn.ChangeTagsForResource(req)
		if err != nil {
			return err
		}
	}

	return nil
}

// diffTags takes our tags locally and the ones remotely and returns
// the set of tags that must be created, and the set of tags that must
// be destroyed.
func diffTagsR53(oldTags, newTags []route53.Tag) ([]route53.Tag, []route53.Tag) {
	// First, we're creating everything we have
	create := make(map[string]interface{})
	for _, t := range newTags {
		create[*t.Key] = *t.Value
	}

	// Build the list of what to remove
	var remove []route53.Tag
	for _, t := range oldTags {
		old, ok := create[*t.Key]
		if !ok || old != *t.Value {
			// Delete it!
			remove = append(remove, t)
		}
	}

	return tagsFromMapR53(create), remove
}

// tagsFromMap returns the tags for the given map of data.
func tagsFromMapR53(m map[string]interface{}) []route53.Tag {
	result := make([]route53.Tag, 0, len(m))
	for k, v := range m {
		result = append(result, route53.Tag{
			Key:   aws.String(k),
			Value: aws.String(v.(string)),
		})
	}

	return result
}

// tagsToMap turns the list of tags into a map.
func tagsToMapR53(ts []route53.Tag) map[string]string {
	result := make(map[string]string)
	for _, t := range ts {
		result[*t.Key] = *t.Value
	}

	return result
}