Update handling of missing kernel headers to better reflect warning status

src/pixie_cli/pkg/cmd/deploy.go

@@ -620,7 +620,7 @@ func waitForHealthCheckTaskGenerator(cloudAddr string, clusterID uuid.UUID) func
 				}
 				// The health check warning error indicates the cluster successfully deployed, but there are some warnings.
 				// Return the error to end the polling and show the warnings.
-				if _, ok := err.(*vizier.HealthCheckWarning); ok {
+				if _, ok := err.(*components.UIWarning); ok {
 					return err
 				}
 				time.Sleep(5 * time.Second)
@@ -642,15 +642,13 @@ func waitForHealthCheck(cloudAddr string, clusterID uuid.UUID, clientset *kubern
 	hc := utils.NewSerialTaskRunner(healthCheckJobs)
 	err := hc.RunAndMonitor()
 	if err != nil {
-		if _, ok := err.(*vizier.HealthCheckWarning); ok {
-			utils.WithError(err).Error("Pixie healthcheck detected the following warnings:")
-		} else {
-			_ = pxanalytics.Client().Enqueue(&analytics.Track{
-				UserId: pxconfig.Cfg().UniqueClientID,
-				Event:  "Deploy Healthcheck Failed",
-				Properties: analytics.NewProperties().
-					Set("err", err.Error()),
-			})
+		_ = pxanalytics.Client().Enqueue(&analytics.Track{
+			UserId: pxconfig.Cfg().UniqueClientID,
+			Event:  "Deploy Healthcheck Failed",
+			Properties: analytics.NewProperties().
+				Set("err", err.Error()),
+		})
+		if _, ok := err.(*components.UIWarning); !ok {
 			utils.WithError(err).Fatal("Failed Pixie healthcheck")
 		}
 	}

src/pixie_cli/pkg/components/spinner.go

@@ -108,6 +108,9 @@ func (d *statusDecorator) Decor(stat *decor.Statistics) string {
 		return ""
 	}
 	if d.err != nil {
+		if _, ok := d.err.(*UIWarning); ok {
+			return StatusWarn(d.width)
+		}
 		return StatusErr(d.width)
 	}
 	return StatusOK(d.width)
@@ -136,6 +139,9 @@ func (d *errorViewDecorator) Decor(stat *decor.Statistics) string {
 	if d.err == nil {
 		return ""
 	}
+	if _, ok := d.err.(*UIWarning); ok {
+		return color.YellowString(fmt.Sprintf(" WARN: %s", d.err.Error()))
+	}
 	return color.RedString(fmt.Sprintf(" ERR: %s", d.err.Error()))
 }
 

src/pixie_cli/pkg/components/status.go

@@ -25,10 +25,26 @@ import (
 )
 
 var (
-	statusOK  = "\u2714"
-	statusErr = "\u2715"
+	statusOK   = "\u2714"
+	statusErr  = "\u2715"
+	statusWarn = "\u26a0"
 )
 
+// UIWarning is a wrapper type that marks errors as warnings for UI display.
+// Errors wrapped in UIWarning will be displayed with yellow warning colors
+// instead of red error colors in the spinner table.
+type UIWarning struct {
+	Err error
+}
+
+func (w UIWarning) Error() string {
+	return w.Err.Error()
+}
+
+func (w UIWarning) Unwrap() error {
+	return w.Err
+}
+
 func computePadding(s string, pad int) (int, int) {
 	var padS, padE int
 	pad -= len([]rune(s))
@@ -55,3 +71,9 @@ func StatusErr(pad int) string {
 	padS, padE := computePadding(statusErr, pad)
 	return strings.Repeat(" ", padS) + color.RedString(statusErr) + strings.Repeat(" ", padE)
 }
+
+// StatusWarn prints out the default Warn symbol, center padded to the size specified.
+func StatusWarn(pad int) string {
+	padS, padE := computePadding(statusWarn, pad)
+	return strings.Repeat(" ", padS) + color.YellowString(statusWarn) + strings.Repeat(" ", padE)
+}

src/pixie_cli/pkg/vizier/logs.go

@@ -30,6 +30,7 @@ import (
 	"k8s.io/client-go/kubernetes"
 	"k8s.io/client-go/rest"
 
+	"px.dev/pixie/src/pixie_cli/pkg/components"
 	"px.dev/pixie/src/utils/script"
 	"px.dev/pixie/src/utils/shared/k8s"
 )
@@ -132,7 +133,7 @@ func (c *LogCollector) CollectPixieLogs(fName string) error {
 	outputCh, err := RunSimpleHealthCheckScript(c.br, c.cloudAddr, clusterID)
 	if err != nil {
 		entry := log.WithError(err)
-		if _, ok := err.(*HealthCheckWarning); ok {
+		if _, ok := err.(*components.UIWarning); ok {
 			entry.Warn("healthcheck script detected the following warnings:")
 		} else {
 			entry.Warn("failed to run healthcheck script")

src/pixie_cli/pkg/vizier/script.go

@@ -44,8 +44,10 @@ import (
 )
 
 const (
-	equalityThreshold          = 0.01
-	headersInstalledPercColumn = "headers_installed_percent" // must match the column in px/agent_status_diagnostics
+	equalityThreshold                = 0.01
+	headersInstalledPercColumn       = "headers_installed_percent" // must match the column in px/agent_status_diagnostics
+	missingKernelHeadersMsg          = "Detected missing kernel headers on your cluster's nodes. This may cause issues with the Pixie agent. Please see https://px.dev/kernel-headers for more details."
+	missingKernelHeadersSuspectedMsg = "Detected missing kernel headers on your cluster's nodes. This may cause issues with the Pixie agent. Please see https://px.dev/kernel-headers for more details. If you are using a distro kernel, this is expected and can be ignored."
 )
 
 type taskWrapper struct {
@@ -266,18 +268,6 @@ func RunScript(ctx context.Context, conns []*Connector, execScript *script.Execu
 	return mergedResponses, nil
 }
 
-type HealthCheckWarning struct {
-	message string
-}
-
-func (h *HealthCheckWarning) Error() string {
-	return h.message
-}
-
-func newHealthCheckWarning(message string) error {
-	return &HealthCheckWarning{message}
-}
-
 func evaluateHealthCheckResult(output string) error {
 	jsonData := make(map[string]interface{})
 
@@ -289,12 +279,11 @@ func evaluateHealthCheckResult(output string) error {
 		switch t := v.(type) {
 		case float64:
 			if math.Abs(1.0-t) > equalityThreshold {
-				msg := "Detected missing kernel headers on your cluster's nodes. This may cause issues with the Pixie agent. Please install kernel headers on all nodes."
-				return newHealthCheckWarning(msg)
+				return &components.UIWarning{Err: fmt.Errorf("%s", missingKernelHeadersMsg)}
 			}
 		}
 	} else {
-		return newHealthCheckWarning("Unable to detect if the cluster's nodes have the distro kernel headers installed (vizier too old to perform this check). Please ensure that the kernel headers are installed on all nodes.")
+		return &components.UIWarning{Err: fmt.Errorf("%s", missingKernelHeadersSuspectedMsg)}
 	}
 	return nil
 }