Skip upload of empty recording files

UploadKerberosVault now checks the file size returned by os.Stat and skips uploading (without retrying) when the recording file is empty, avoiding unnecessary requests to the vault. Adds a test covering this behavior.

machinery/src/cloud/kerberos_vault.go

@@ -35,10 +35,15 @@ func UploadKerberosVault(configuration *models.Configuration, fileName string) (
 	// This can happen when the file was already removed (e.g. cleanup, or an
 	// earlier successful upload). Skip it so the watcher drops the marker
 	// instead of retrying indefinitely.
-	if _, err := os.Stat("data/recordings/" + fileName); err != nil {
+	info, err := os.Stat("data/recordings/" + fileName)
+	if err != nil {
 		log.Log.Info("UploadKerberosVault: skipping " + fileName + ", file doesn't exist anymore")
 		return false, false, nil
 	}
+	if info.Size() == 0 {
+		log.Log.Warning("UploadKerberosVault: skipping " + fileName + ", recording is empty")
+		return false, false, nil
+	}
 
 	// timestamp_microseconds_instanceName_regionCoordinates_numberOfChanges_token
 	// 1564859471_6-474162_oprit_577-283-727-375_1153_27.mp4

machinery/src/cloud/tus_client_test.go

@@ -264,6 +264,36 @@ func testVault(uri string) models.KStorage {
 	}
 }
 
+func TestUploadKerberosVaultSkipsEmptyRecording(t *testing.T) {
+	fileName := "1787015373_3-654_office-camera17_0-0-0-0_-1_1960.mp4"
+	withRecording(t, fileName, nil)
+
+	requestCount := 0
+	server := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		requestCount++
+		w.WriteHeader(http.StatusInternalServerError)
+	}))
+	defer server.Close()
+
+	vault := testVault(server.URL)
+	configuration := &models.Configuration{Config: models.Config{
+		Key:               "device-key",
+		KStorage:          &vault,
+		KStorageSecondary: &models.KStorage{},
+	}}
+
+	uploaded, configured, err := UploadKerberosVault(configuration, fileName)
+	if err != nil {
+		t.Fatalf("UploadKerberosVault() error = %v", err)
+	}
+	if uploaded || configured {
+		t.Fatalf("UploadKerberosVault() uploaded/configured = %v/%v, want false/false", uploaded, configured)
+	}
+	if requestCount != 0 {
+		t.Fatalf("Vault received %d requests, want 0", requestCount)
+	}
+}
+
 func TestUploadVaultResumable_HappyPath(t *testing.T) {
 	srv := newFakeTus()
 	ts := httptest.NewServer(srv)