Fix upstream timeout for large downloads

internal/server/http_client.go

@@ -31,9 +31,12 @@ func NewUpstreamClient(cfg *config.Config) *http.Client {
 		timeout = cfg.Global.UpstreamTimeout.DurationValue()
 	}
 
+	transport := defaultTransport.Clone()
+	// Use UpstreamTimeout as ResponseHeaderTimeout to avoid killing long streaming downloads.
+	transport.ResponseHeaderTimeout = timeout
+
 	return &http.Client{
-		Timeout:   timeout,
-		Transport: defaultTransport.Clone(),
+		Transport: transport,
 	}
 }
 

internal/server/http_client_test.go

@@ -16,8 +16,12 @@ func TestNewUpstreamClientUsesConfigTimeout(t *testing.T) {
 	}
 
 	client := NewUpstreamClient(cfg)
-	if client.Timeout != 45*time.Second {
-		t.Fatalf("expected timeout 45s, got %s", client.Timeout)
+	transport, ok := client.Transport.(*http.Transport)
+	if !ok {
+		t.Fatalf("expected *http.Transport, got %T", client.Transport)
+	}
+	if transport.ResponseHeaderTimeout != 45*time.Second {
+		t.Fatalf("expected response header timeout 45s, got %s", transport.ResponseHeaderTimeout)
 	}
 }