tctl: fix tctl top colors on dark terminals

If we leave `TextStyle` empty on UI elements, it will use the default
foreground color defined by the terminal (light for dark terminals and
vice versa). Same goes for `BorderStyle`.

A few other tweaks to UI and source metrics:
- update table ratios to prevent hiding output rows on short (height)
  terminal windows
- update tab selector style to use bold/underline instead of colors to
  mark selected tab
- print `No data` in histogram tables when there are no values
- don't report the local cluster in `remote_clusters` metric

lib/auth/auth.go

@@ -159,13 +159,13 @@ var (
 	generateRequestsCurrent = prometheus.NewGauge(
 		prometheus.GaugeOpts{
 			Name: teleport.MetricGenerateRequestsCurrent,
-			Help: "Number of current generate requests",
+			Help: "Number of current generate requests for server keys",
 		},
 	)
 	generateRequestsLatencies = prometheus.NewHistogram(
 		prometheus.HistogramOpts{
 			Name: teleport.MetricGenerateRequestsHistogram,
-			Help: "Latency for generate requests",
+			Help: "Latency for generate requests for server keys",
 			// lowest bucket start of upper bound 0.001 sec (1 ms) with factor 2
 			// highest bucket start of 0.001 sec * 2^15 == 32.768 sec
 			Buckets: prometheus.ExponentialBuckets(0.001, 2, 16),

lib/reversetunnel/srv.go

@@ -44,14 +44,14 @@ import (
 var (
 	remoteClustersStats = prometheus.NewGaugeVec(
 		prometheus.GaugeOpts{
-			Name: "remote_clusters",
+			Name: teleport.MetricRemoteClusters,
 			Help: "Number inbound connections from remote clusters and clusters stats",
 		},
 		[]string{"cluster"},
 	)
 	trustedClustersStats = prometheus.NewGaugeVec(
 		prometheus.GaugeOpts{
-			Name: "trusted_clusters",
+			Name: teleport.MetricTrustedClusters,
 			Help: "Number of tunnels per state",
 		},
 		[]string{"cluster", "state"},
@@ -400,13 +400,12 @@ func (s *server) fetchClusterPeers() error {
 }
 
 func (s *server) reportClusterStats() error {
-	defer func() {
-		if r := recover(); r != nil {
-			s.Warningf("Recovered from panic: %v.", r)
-		}
-	}()
 	clusters := s.GetSites()
 	for _, cluster := range clusters {
+		if _, ok := cluster.(*localSite); ok {
+			// Don't count local cluster tunnels.
+			continue
+		}
 		gauge, err := remoteClustersStats.GetMetricWithLabelValues(cluster.GetName())
 		if err != nil {
 			return trace.Wrap(err)

metrics.go

@@ -37,6 +37,9 @@ const (
 	// MetricRemoteClusters measures connected remote clusters
 	MetricRemoteClusters = "remote_clusters"
 
+	// MetricTrustedClusters counts trusted clusters
+	MetricTrustedClusters = "trusted_clusters"
+
 	// TagCluster is a metric tag for a cluster
 	TagCluster = "cluster"
 )

tool/tctl/common/top_command.go

@@ -134,16 +134,13 @@ func (c *TopCommand) Top(client *roundtrip.Client) error {
 
 func (c *TopCommand) render(ctx context.Context, re Report, eventID string) error {
 	h := widgets.NewParagraph()
-	h.Text = ""
 	h.Text = fmt.Sprintf("Report Generated at %v for host %v. Press <q> or Ctrl-C to quit.",
 		re.Timestamp.Format(teleport.HumanDateFormatSeconds), re.Hostname)
-	h.BorderStyle = ui.NewStyle(ui.ColorBlack)
 	h.Border = false
 	h.TextStyle = ui.NewStyle(ui.ColorMagenta)
 
 	backendRequestsTable := func(title string, b BackendStats) *widgets.Table {
 		t := widgets.NewTable()
-		t.BorderStyle = ui.NewStyle(ui.ColorBlack)
 		t.Title = title
 		t.TitleStyle = ui.NewStyle(ui.ColorCyan)
 		t.ColumnWidths = []int{10, 10, 10, 50000}
@@ -160,17 +157,14 @@ func (c *TopCommand) render(ctx context.Context, re Report, eventID string) erro
 					req.Key.Key,
 				})
 		}
-		t.TextStyle = ui.NewStyle(ui.ColorBlack)
 		return t
 	}
 
 	t1 := widgets.NewTable()
 	t1.Title = "Cluster Stats"
 	t1.TitleStyle = ui.NewStyle(ui.ColorCyan)
-	t1.BorderStyle = ui.NewStyle(ui.ColorBlack)
 	t1.ColumnWidths = []int{30, 50000}
 	t1.RowSeparator = false
-	t1.TextStyle = ui.NewStyle(ui.ColorBlack)
 	t1.Rows = [][]string{
 		[]string{"Interactive Sessions", humanize.FormatFloat("", re.Cluster.InteractiveSessions)},
 		[]string{"Cert Gen Active Requests", humanize.FormatFloat("", re.Cluster.GenerateRequests)},
@@ -187,10 +181,8 @@ func (c *TopCommand) render(ctx context.Context, re Report, eventID string) erro
 	t2 := widgets.NewTable()
 	t2.Title = "Process Stats"
 	t2.TitleStyle = ui.NewStyle(ui.ColorCyan)
-	t2.BorderStyle = ui.NewStyle(ui.ColorBlack)
 	t2.ColumnWidths = []int{30, 50000}
 	t2.RowSeparator = false
-	t2.TextStyle = ui.NewStyle(ui.ColorBlack)
 	t2.Rows = [][]string{
 		[]string{"Start Time", re.Process.StartTime.Format(teleport.HumanDateFormatSeconds)},
 		[]string{"Resident Memory Bytes", humanize.Bytes(uint64(re.Process.ResidentMemoryBytes))},
@@ -202,10 +194,8 @@ func (c *TopCommand) render(ctx context.Context, re Report, eventID string) erro
 	t3 := widgets.NewTable()
 	t3.Title = "Go Runtime Stats"
 	t3.TitleStyle = ui.NewStyle(ui.ColorCyan)
-	t3.BorderStyle = ui.NewStyle(ui.ColorBlack)
 	t3.ColumnWidths = []int{30, 50000}
 	t3.RowSeparator = false
-	t3.TextStyle = ui.NewStyle(ui.ColorBlack)
 	t3.Rows = [][]string{
 		[]string{"Allocated Memory", humanize.Bytes(uint64(re.Go.AllocBytes))},
 		[]string{"Goroutines", humanize.FormatFloat("", re.Go.Goroutines)},
@@ -219,10 +209,16 @@ func (c *TopCommand) render(ctx context.Context, re Report, eventID string) erro
 		t := widgets.NewTable()
 		t.Title = title
 		t.TitleStyle = ui.NewStyle(ui.ColorCyan)
-		t.BorderStyle = ui.NewStyle(ui.ColorBlack)
+
+		if hist.Count == 0 {
+			t.Rows = [][]string{
+				[]string{"No data"},
+			}
+			return t
+		}
+
 		t.ColumnWidths = []int{30, 50000}
 		t.RowSeparator = false
-		t.TextStyle = ui.NewStyle(ui.ColorBlack)
 		t.Rows = [][]string{
 			[]string{"Percentile", "Latency"},
 		}
@@ -240,8 +236,8 @@ func (c *TopCommand) render(ctx context.Context, re Report, eventID string) erro
 	grid.SetRect(0, 0, termWidth, termHeight)
 
 	tabpane := widgets.NewTabPane("[1] Common", "[2] Backend Stats", "[3] Cache Stats")
-	tabpane.ActiveTabStyle = ui.NewStyle(ui.ColorCyan)
-	tabpane.InactiveTabStyle = ui.NewStyle(ui.ColorBlack)
+	tabpane.ActiveTabStyle = ui.NewStyle(ui.ColorCyan, ui.ColorClear, ui.ModifierBold|ui.ModifierUnderline)
+	tabpane.InactiveTabStyle = ui.NewStyle(ui.ColorCyan)
 	tabpane.Border = false
 
 	switch eventID {
@@ -254,12 +250,12 @@ func (c *TopCommand) render(ctx context.Context, re Report, eventID string) erro
 			),
 			ui.NewRow(0.95,
 				ui.NewCol(0.5,
-					ui.NewRow(0.15, t1),
-					ui.NewRow(0.15, t2),
-					ui.NewRow(0.15, t3),
+					ui.NewRow(0.3, t1),
+					ui.NewRow(0.3, t2),
+					ui.NewRow(0.3, t3),
 				),
 				ui.NewCol(0.5,
-					ui.NewRow(0.3, percentileTable("Generate Certificates Histogram", re.Cluster.GenerateRequestsHistogram)),
+					ui.NewRow(0.3, percentileTable("Generate Server Certificates Histogram", re.Cluster.GenerateRequestsHistogram)),
 				),
 			),
 		)