Take all the buckets and list their website policy if any. Support multi-region and profile or static auth.

list_all_s3_buckets_websiste_policies.go

package main

import (
	"context"
	"encoding/json"
	"flag"
	"io/ioutil"
	"log"
	"time"

	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/awserr"
	"github.com/aws/aws-sdk-go/aws/credentials"
	"github.com/aws/aws-sdk-go/aws/session"
	"github.com/aws/aws-sdk-go/service/s3"

	"github.com/gobike/envflag"
)

type awsS3Websites struct {
	Name             string
	Region           string
	HasWebsiteConfig bool
	RedirectToHost   string            `json:",omitempty"`
	RoutingRules     []*s3.RoutingRule `json:",omitempty"`
	Tags             map[string]string `json:",omitempty"`
}

func main() {
	var (
		awsRegion      string
		awsProfile     string
		awsKey         string
		awsSecret      string
		awsToken       string
		outputFilePath string
		outputObject   []*awsS3Websites
	)

	flag.StringVar(&awsRegion, "aws-region", "us-east-1", "AWS Region to use")
	flag.StringVar(&awsProfile, "aws-profile", "", "AWS profile to use - ignored if empty")
	flag.StringVar(&awsKey, "aws-access-key-id", "", "AWS key id to use - ignored if empty")
	flag.StringVar(&awsSecret, "aws-secret-access-key", "", "AWS secret key to use - ignored if aws-access-key-id is empty")
	flag.StringVar(&awsToken, "aws-session-token", "", "AWS session token to use - ignored if aws-access-key-id is empty")
	flag.StringVar(&outputFilePath, "output-json-path", "/tmp/s3_endpoints.json", "Path to the json output")
	envflag.Parse()

	awsConfig := &aws.Config{Region: aws.String(awsRegion)}
	if awsKey != "" {
		awsConfig.Credentials = credentials.NewStaticCredentials(awsKey, awsSecret, awsToken)
	}
	awsSessOpts := &session.Options{Config: *awsConfig}
	if awsProfile != "" {
		awsSessOpts.SharedConfigState = session.SharedConfigEnable
		awsSessOpts.Profile = awsProfile
	}
	sess := session.Must(session.NewSessionWithOptions(*awsSessOpts))
	svc := s3.New(sess)

	bucketsList, err := svc.ListBuckets(&s3.ListBucketsInput{})
	if err != nil {
		log.Fatal(err.Error())
	}

	for _, bucket := range bucketsList.Buckets {
		currentBucketRegion := awsRegion
		// Make sure to be compliant with signature v4 when querying buckets that
		// are not in the default region
		ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
		defer cancel()
		bucketRegion, err := svc.GetBucketLocationWithContext(ctx, &s3.GetBucketLocationInput{Bucket: aws.String(*bucket.Name)}, s3.WithNormalizeBucketLocation)
		if err != nil {
			log.Printf("[WARNING] while retrieving the bucket location for %s: %s\n", *bucket.Name, err.Error())
		}
		regionalSvc := svc
		if bucketRegion.LocationConstraint != nil {
			currentBucketRegion = *bucketRegion.LocationConstraint
			regionalSvc = s3.New(sess.Copy(&aws.Config{Region: bucketRegion.LocationConstraint}))
		}

		ws := &awsS3Websites{Name: *bucket.Name, Region: currentBucketRegion, HasWebsiteConfig: false}

		// Get the bucket tag
		ws.Tags = make(map[string]string)
		bucketTags, err := regionalSvc.GetBucketTagging(&s3.GetBucketTaggingInput{Bucket: aws.String(*bucket.Name)})
		if err != nil {
			if awsErr, ok := err.(awserr.Error); ok && awsErr.Code() != "NoSuchTagSet" {
				log.Println(err.Error())
			}
		}
		for _, tag := range bucketTags.TagSet {
			ws.Tags[*tag.Key] = *tag.Value
		}

		// Get the website config
		website, err := regionalSvc.GetBucketWebsite(&s3.GetBucketWebsiteInput{Bucket: aws.String(*bucket.Name)})
		if err != nil {
			if awsErr, ok := err.(awserr.Error); ok && awsErr.Code() != "NoSuchWebsiteConfiguration" {
				log.Printf("[WARNING] while retrieving the bucket website for %s: %s\n", *bucket.Name, err.Error())
				// } else {
				//	log.Printf("Bucket %s has no website configured", *bucket.Name)
			}
		} else {
			ws.RoutingRules = website.RoutingRules
			ws.HasWebsiteConfig = true
			if website.RedirectAllRequestsTo != nil {
				ws.RedirectToHost = *website.RedirectAllRequestsTo.HostName
			}
		}
		outputObject = append(outputObject, ws)
	}
	outputJson, err := json.MarshalIndent(outputObject, "", "  ")
	if err != nil {
		log.Fatal(err)
	}
	err = ioutil.WriteFile(outputFilePath, outputJson, 0600)
	if err != nil {
		log.Fatal(err)
	}
}