1 files changed, 32 insertions, 6 deletions

diff --git a/internal/storage/storage.go b/internal/storage/storage.go
index 5d5baf283..f3cb814f1 100644
--- a/internal/storage/storage.go
+++ b/internal/storage/storage.go
@@ -79,6 +79,7 @@ type Driver struct {
 	Proxy          bool
 	Bucket         string
 	PresignedCache *ttl.Cache[string, PresignedURL]
+	RedirectURL    string
 }
 
 // Get returns the byte value for key in storage.
@@ -163,12 +164,27 @@ func (d *Driver) URL(ctx context.Context, key string) *PresignedURL {
 		return &e.Value
 	}
 
-	u, err := s3.Client().PresignedGetObject(ctx, d.Bucket, key, urlCacheTTL, url.Values{
-		"response-content-type": []string{mime.TypeByExtension(path.Ext(key))},
-	})
-	if err != nil {
-		// If URL request fails, fallback is to fetch the file. So ignore the error here
-		return nil
+	var (
+		u   *url.URL
+		err error
+	)
+
+	if d.RedirectURL != "" {
+		u, err = url.Parse(d.RedirectURL + "/" + key)
+		if err != nil {
+			// If URL parsing fails, fallback is to
+			// fetch the file. So ignore the error here
+			return nil
+		}
+	} else {
+		u, err = s3.Client().PresignedGetObject(ctx, d.Bucket, key, urlCacheTTL, url.Values{
+			"response-content-type": []string{mime.TypeByExtension(path.Ext(key))},
+		})
+		if err != nil {
+			// If URL request fails, fallback is to
+			// fetch the file. So ignore the error here
+			return nil
+		}
 	}
 
 	psu := PresignedURL{
@@ -204,6 +220,14 @@ func (d *Driver) ProbeCSPUri(ctx context.Context) (string, error) {
 		return "", nil
 	}
 
+	// If an S3 redirect URL is set, just
+	// return this URL without probing; we
+	// likely don't have write access on it
+	// anyway since it's probs a CDN bucket.
+	if d.RedirectURL != "" {
+		return d.RedirectURL + "/", nil
+	}
+
 	const cspKey = "gotosocial-csp-probe"
 
 	// Create an empty file in S3 storage.
@@ -273,6 +297,7 @@ func NewS3Storage() (*Driver, error) {
 	secret := config.GetStorageS3SecretKey()
 	secure := config.GetStorageS3UseSSL()
 	bucket := config.GetStorageS3BucketName()
+	redirectURL := config.GetStorageS3RedirectURL()
 
 	// Open the s3 storage implementation
 	s3, err := s3.Open(endpoint, bucket, &s3.Config{
@@ -300,5 +325,6 @@ func NewS3Storage() (*Driver, error) {
 		Bucket:         config.GetStorageS3BucketName(),
 		Storage:        s3,
 		PresignedCache: presignedCache,
+		RedirectURL:    redirectURL,
 	}, nil
 }