TUN-3198: Handle errors while running tunnel UI

cmd/cloudflared/tunnel/cmd.go

@@ -36,6 +36,7 @@ import (
 	"github.com/cloudflare/cloudflared/tunneldns"
 	"github.com/cloudflare/cloudflared/tunnelstore"
 	"github.com/cloudflare/cloudflared/websocket"
+	"github.com/rivo/tview"
 
 	"github.com/coreos/go-systemd/daemon"
 	"github.com/facebookgo/grace/gracenet"
@@ -215,11 +216,23 @@ func TunnelCommand(c *cli.Context) error {
 	if name := c.String("name"); name != "" {
 		return adhocNamedTunnel(c, name)
 	}
+
+	if c.IsSet("launch-ui") {
+		// Create textView to stream logs to
+		logTextView := ui.NewDynamicColorTextView()
+		logger, err := createLoggerConfigured(c, false, logTextView)
+		if err != nil {
+			return errors.Wrap(err, "error setting up logger")
+		}
+		return StartServer(c, version, shutdownC, graceShutdownC, nil, logger, logTextView)
+	}
+
 	logger, err := createLogger(c, false)
 	if err != nil {
 		return errors.Wrap(err, "error setting up logger")
 	}
-	return StartServer(c, version, shutdownC, graceShutdownC, nil, logger)
+
+	return StartServer(c, version, shutdownC, graceShutdownC, nil, logger, nil)
 }
 
 func Init(v string, s, g chan struct{}) {
@@ -268,7 +281,7 @@ func routeFromFlag(c *cli.Context, tunnelID uuid.UUID) (tunnelstore.Route, bool)
 	return nil, false
 }
 
-func createLogger(c *cli.Context, isTransport bool) (logger.Service, error) {
+func createLogger(c *cli.Context, isTransport bool) (*logger.OutputWriter, error) {
 	loggerOpts := []logger.Option{}
 
 	logPath := c.String("logfile")
@@ -297,7 +310,26 @@ func createLogger(c *cli.Context, isTransport bool) (logger.Service, error) {
 	return logger.New(loggerOpts...)
 }
 
-func StartServer(c *cli.Context, version string, shutdownC, graceShutdownC chan struct{}, namedTunnel *origin.NamedTunnelConfig, logger logger.Service) error {
+// Create logger configured for use in UI
+func createLoggerConfigured(c *cli.Context, isTransport bool, logTextView *tview.TextView) (logger.Service, error) {
+	l, err := createLogger(c, isTransport)
+	if err != nil {
+		return nil, errors.Wrap(err, "Error creating logger")
+	}
+
+	logLevel := c.String("loglevel")
+	supportedLevels, err := logger.GetSupportedLevels(logLevel)
+	if err != nil {
+		return nil, errors.Wrap(err, "Error parsing supported levels")
+	}
+
+	// Add TextView as a group to write output to
+	l.Add(logTextView, logger.NewUIFormatter(time.RFC3339), supportedLevels...)
+
+	return l, nil
+}
+
+func StartServer(c *cli.Context, version string, shutdownC, graceShutdownC chan struct{}, namedTunnel *origin.NamedTunnelConfig, logger logger.Service, logTextView *tview.TextView) error {
 	_ = raven.SetDSN(sentryDSN)
 	var wg sync.WaitGroup
 	listeners := gracenet.Net{}
@@ -537,7 +569,7 @@ func StartServer(c *cli.Context, version string, shutdownC, graceShutdownC chan
 		tunnelConfig.TunnelEventChan = tunnelEventChan
 
 		tunnelInfo := ui.NewUIModel(version, hostname, metricsListener.Addr().String(), tunnelConfig.OriginUrl, tunnelConfig.HAConnections)
-		tunnelInfo.LaunchUI(ctx, logger, tunnelEventChan)
+		tunnelInfo.LaunchUI(ctx, logger, tunnelEventChan, logTextView)
 	}
 
 	return waitToShutdown(&wg, errC, shutdownC, graceShutdownC, c.Duration("grace-period"), logger)
@@ -1138,7 +1170,7 @@ func tunnelFlags(shouldHide bool) []cli.Flag {
 		}),
 		altsrc.NewBoolFlag(&cli.BoolFlag{
 			Name:   "launch-ui",
-			Usage:  "Launch tunnel UI and disable logs",
+			Usage:  "Launch tunnel UI. Tunnel logs are scrollable via 'j', 'k', or arrow keys.",
 			Value:  false,
 			Hidden: shouldHide,
 		}),

cmd/cloudflared/tunnel/subcommand_context.go

@@ -10,12 +10,14 @@ import (
 
 	"github.com/cloudflare/cloudflared/certutil"
 	"github.com/cloudflare/cloudflared/cmd/cloudflared/config"
+	"github.com/cloudflare/cloudflared/cmd/cloudflared/ui"
 	"github.com/cloudflare/cloudflared/logger"
 	"github.com/cloudflare/cloudflared/origin"
 	"github.com/cloudflare/cloudflared/tunnelrpc/pogs"
 	"github.com/cloudflare/cloudflared/tunnelstore"
 	"github.com/google/uuid"
 	"github.com/pkg/errors"
+	"github.com/rivo/tview"
 	"github.com/urfave/cli/v2"
 )
 
@@ -24,6 +26,7 @@ import (
 type subcommandContext struct {
 	c          *cli.Context
 	logger     logger.Service
+	uiTextView *tview.TextView
 
 	// These fields should be accessed using their respective Getter
 	tunnelstoreClient tunnelstore.Client
@@ -31,6 +34,20 @@ type subcommandContext struct {
 }
 
 func newSubcommandContext(c *cli.Context) (*subcommandContext, error) {
+	if c.IsSet("launch-ui") {
+		// Create textView to stream logs to
+		logTextView := ui.NewDynamicColorTextView()
+		logger, err := createLoggerConfigured(c, false, logTextView)
+		if err != nil {
+			return nil, errors.Wrap(err, "error setting up logger")
+		}
+		return &subcommandContext{
+			c:          c,
+			logger:     logger,
+			uiTextView: logTextView,
+		}, nil
+	}
+
 	logger, err := createLogger(c, false)
 	if err != nil {
 		return nil, errors.Wrap(err, "error setting up logger")
@@ -237,7 +254,8 @@ func (sc *subcommandContext) run(tunnelID uuid.UUID) error {
 	if err != nil {
 		return err
 	}
-	return StartServer(sc.c, version, shutdownC, graceShutdownC, &origin.NamedTunnelConfig{Auth: *credentials, ID: tunnelID}, sc.logger)
+
+	return StartServer(sc.c, version, shutdownC, graceShutdownC, &origin.NamedTunnelConfig{Auth: *credentials, ID: tunnelID}, sc.logger, sc.uiTextView)
 }
 
 func (sc *subcommandContext) cleanupConnections(tunnelIDs []uuid.UUID) error {

cmd/cloudflared/ui/launch_ui.go

@@ -56,7 +56,7 @@ func NewUIModel(version, hostname, metricsURL, proxyURL string, haConnections in
 	}
 }
 
-func (data *uiModel) LaunchUI(ctx context.Context, logger logger.Service, tunnelEventChan <-chan TunnelEvent) {
+func (data *uiModel) LaunchUI(ctx context.Context, logger logger.Service, tunnelEventChan <-chan TunnelEvent, logTextView *tview.TextView) {
 	palette := palette{url: "#4682B4", connected: "#00FF00", defaultText: "white", disconnected: "red", reconnecting: "orange"}
 
 	app := tview.NewApplication()
@@ -86,12 +86,14 @@ func (data *uiModel) LaunchUI(ctx context.Context, logger logger.Service, tunnel
 	tunnelHostText := tview.NewTextView().SetText(data.edgeURL)
 
 	grid.AddItem(tunnelHostText, 0, 1, 1, 1, 0, 0, false)
-	grid.AddItem(newDynamicColorTextView().SetText(fmt.Sprintf("[%s]\u2022[%s] Proxying to [%s::b]%s", palette.connected, palette.defaultText, palette.url, data.proxyURL)), 1, 1, 1, 1, 0, 0, false)
+	grid.AddItem(NewDynamicColorTextView().SetText(fmt.Sprintf("[%s]\u2022[%s] Proxying to [%s::b]%s", palette.connected, palette.defaultText, palette.url, data.proxyURL)), 1, 1, 1, 1, 0, 0, false)
 
 	grid.AddItem(connTable, 2, 1, 1, 1, 0, 0, false)
 
-	grid.AddItem(newDynamicColorTextView().SetText(fmt.Sprintf("Metrics at [%s::b]%s/metrics", palette.url, data.metricsURL)), 3, 1, 1, 1, 0, 0, false)
+	grid.AddItem(NewDynamicColorTextView().SetText(fmt.Sprintf("Metrics at [%s::b]%s/metrics", palette.url, data.metricsURL)), 3, 1, 1, 1, 0, 0, false)
-	grid.AddItem(tview.NewBox(), 4, 0, 1, 2, 0, 0, false)
+	// Add TextView to stream logs
+	// LOGS header is displayed in bold
+	grid.AddItem(logTextView.SetText("[::b]LOGS:[::-]\n\n").SetChangedFunc(handleNewText(app, logTextView)), 4, 0, 5, 2, 0, 0, false)
 
 	go func() {
 		for {
@@ -125,10 +127,19 @@ func (data *uiModel) LaunchUI(ctx context.Context, logger logger.Service, tunnel
 	}()
 }
 
-func newDynamicColorTextView() *tview.TextView {
+func NewDynamicColorTextView() *tview.TextView {
 	return tview.NewTextView().SetDynamicColors(true)
 }
 
+// Re-draws application when new logs are streamed to UI
+func handleNewText(app *tview.Application, logTextView *tview.TextView) func() {
+	return func() {
+		app.Draw()
+		// SetFocus to enable scrolling in textview
+		app.SetFocus(logTextView)
+	}
+}
+
 func (data *uiModel) changeConnStatus(event TunnelEvent, table *tview.Table, logger logger.Service, palette palette) {
 	index := int(event.Index)
 	// Get connection location and state

logger/create.go

@@ -85,6 +85,14 @@ func LogLevelString(level string) Option {
 	}
 }
 
+func GetSupportedLevels(level string) ([]Level, error) {
+	supported, err := ParseLevelString(level)
+	if err != nil {
+		return nil, err
+	}
+	return supported, nil
+}
+
 // Parse builds the Options struct so the caller knows what actions should be run
 func Parse(opts ...Option) (*Options, error) {
 	options := &Options{}
@@ -98,7 +106,7 @@ func Parse(opts ...Option) (*Options, error) {
 
 // New setups a new logger based on the options.
 // The default behavior is to write to standard out
-func New(opts ...Option) (Service, error) {
+func New(opts ...Option) (*OutputWriter, error) {
 	config, err := Parse(opts...)
 
 	if err != nil {
@@ -123,6 +131,7 @@ func New(opts ...Option) (Service, error) {
 			l.Add(os.Stderr, terminalFormatter, config.supportedTerminalLevels...)
 		}
 	}
+
 	return l, nil
 }
 

logger/formatter.go

@@ -63,6 +63,12 @@ type TerminalFormatter struct {
 	supportsColor bool
 }
 
+// UIFormatter is used for streaming logs to UI
+type UIFormatter struct {
+	format        string
+	supportsColor bool
+}
+
 // NewTerminalFormatter creates a Terminal formatter for colored output
 // format is the time format to use for timestamp formatting
 func NewTerminalFormatter(format string) Formatter {
@@ -73,6 +79,35 @@ func NewTerminalFormatter(format string) Formatter {
 	}
 }
 
+func NewUIFormatter(format string) Formatter {
+	supportsColor := (runtime.GOOS != "windows")
+	return &UIFormatter{
+		format:        format,
+		supportsColor: supportsColor,
+	}
+}
+
+// Timestamp uses formatting that is tview-specific for UI
+func (f *UIFormatter) Timestamp(l Level, d time.Time) string {
+	t := ""
+	dateStr := "[" + d.Format(f.format) + "] "
+	switch l {
+	case InfoLevel:
+		t = "[#00ffff]INFO[white]"
+	case ErrorLevel:
+		t = "[red]ERROR[white]"
+	case DebugLevel:
+		t = "[yellow]DEBUG[white]"
+	case FatalLevel:
+		t = "[red]FATAL[white]"
+	}
+	return t + dateStr
+}
+
+func (f *UIFormatter) Content(l Level, c string) string {
+	return c
+}
+
 // Timestamp returns the log level with a matching color to the log type
 func (f *TerminalFormatter) Timestamp(l Level, d time.Time) string {
 	t := ""