Add CDN support for URLs in S3 configuration

server/pkg/controller/file.go

@@ -7,6 +7,7 @@ import (
 	"errors"
 	"fmt"
 	"github.com/ente-io/museum/pkg/controller/access"
+	"net/url"
 	"runtime/debug"
 	"strconv"
 	"strings"
@@ -808,7 +809,16 @@ func (c *FileController) getHotDcSignedUrl(objectKey string) (string, error) {
 		Bucket: c.S3Config.GetHotBucket(),
 		Key:    &objectKey,
 	})
-	return r.Presign(PreSignedRequestValidityDuration)
+
+	presignedUrl, _ := r.Presign(PreSignedRequestValidityDuration)
+
+	cdnUrl, err := c.resolveCdnIfNeeded(presignedUrl, c.S3Config.GetHotBackblazeDC())
+
+	if err != nil {
+		return "", err
+	}
+
+	return cdnUrl, nil
 }
 
 func (c *FileController) getPreSignedURLForDC(objectKey string, dc string) (string, error) {
@@ -817,7 +827,32 @@ func (c *FileController) getPreSignedURLForDC(objectKey string, dc string) (stri
 		Bucket: c.S3Config.GetBucket(dc),
 		Key:    &objectKey,
 	})
-	return r.Presign(PreSignedRequestValidityDuration)
+
+	presignedUrl, _ := r.Presign(PreSignedRequestValidityDuration)
+
+	cdnUrl, err := c.resolveCdnIfNeeded(presignedUrl, dc)
+
+	if err != nil {
+		return "", err
+	}
+
+	return cdnUrl, nil
+}
+
+func (c *FileController) resolveCdnIfNeeded(presignedUrl string, dc string) (string, error) {
+	cdn := c.S3Config.GetCDN(dc)
+
+	if *cdn != "" {
+		parsedUrl, _ := url.Parse(presignedUrl)
+
+		parsedUrl.Host = *cdn
+
+		parsedUrl.Scheme = "https"
+
+		return parsedUrl.String(), nil
+	}
+
+	return presignedUrl, nil
 }
 
 func (c *FileController) sizeOf(objectKey string) (int64, error) {

server/pkg/utils/s3config/s3config.go

@@ -36,6 +36,8 @@ type S3Config struct {
 	s3Configs map[string]*aws.Config
 	// A map from data centers to pre-created S3 clients
 	s3Clients map[string]s3.S3
+	// Optional per-bucket CDN URL
+	cdns map[string]string
 	// Indicates if compliance is enabled for the Wasabi DC.
 	isWasabiComplianceEnabled bool
 	// Indicates if local minio buckets are being used. Enables various
@@ -123,6 +125,7 @@ func (config *S3Config) initialize() {
 	config.buckets = make(map[string]string)
 	config.s3Configs = make(map[string]*aws.Config)
 	config.s3Clients = make(map[string]s3.S3)
+	config.cdns = make(map[string]string)
 
 	usePathStyleURLs := viper.GetBool("s3.use_path_style_urls")
 	areLocalBuckets := viper.GetBool("s3.are_local_buckets")
@@ -150,6 +153,7 @@ func (config *S3Config) initialize() {
 		s3Client := *s3.New(s3Session)
 		config.s3Configs[dc] = &s3Config
 		config.s3Clients[dc] = s3Client
+		config.cdns[dc] = viper.GetString("s3." + dc + ".cdn")
 		if dc == dcWasabiEuropeCentral_v3 {
 			config.isWasabiComplianceEnabled = viper.GetBool("s3." + dc + ".compliance")
 		}
@@ -167,6 +171,11 @@ func (config *S3Config) GetBucket(dcOrBucketID string) *string {
 	return &bucket
 }
 
+func (config *S3Config) GetCDN(dcOrBucketID string) *string {
+	cdn := config.cdns[dcOrBucketID]
+	return &cdn
+}
+
 // GetBucketID returns the bucket ID for the given object type. Note: existing dc are renamed as bucketID
 func (config *S3Config) GetBucketID(oType ente.ObjectType) string {
 	if config.fileDataConfig.HasConfig(oType) {