remove prom check for public-api self-check (#5436)

Currently, public-api is part of the core control-plane where
the prom check fails when ran before the viz extension is installed.
This change comments out that check, Once metrics api is moved into
viz, maybe this check can be part of it instead or directly part of
`linkerd viz check`.

Signed-off-by: Tarun Pothulapati <tarunpothulapati@outlook.com>
Co-authored-by: Kevin Leimkuhler <kevin@kleimkuhler.com>

controller/api/public/grpc_server.go

@@ -45,11 +45,11 @@ type podReport struct {
 }
 
 const (
-	podQuery                   = "max(process_start_time_seconds{%s}) by (pod, namespace)"
-	k8sClientSubsystemName     = "kubernetes"
-	k8sClientCheckDescription  = "control plane can talk to Kubernetes"
-	promClientSubsystemName    = "prometheus"
-	promClientCheckDescription = "control plane can talk to Prometheus"
+	podQuery                  = "max(process_start_time_seconds{%s}) by (pod, namespace)"
+	k8sClientSubsystemName    = "kubernetes"
+	k8sClientCheckDescription = "control plane can talk to Kubernetes"
+	// promClientSubsystemName    = "prometheus"
+	// promClientCheckDescription = "control plane can talk to Prometheus"
 )
 
 func newGrpcServer(
@@ -206,20 +206,23 @@ func (s *grpcServer) SelfCheck(ctx context.Context, in *healthcheckPb.SelfCheckR
 		},
 	}
 
-	if s.prometheusAPI != nil {
-		promClientCheck := &healthcheckPb.CheckResult{
-			SubsystemName:    promClientSubsystemName,
-			CheckDescription: promClientCheckDescription,
-			Status:           healthcheckPb.CheckStatus_OK,
-		}
-		_, err = s.queryProm(ctx, fmt.Sprintf(podQuery, ""))
-		if err != nil {
-			promClientCheck.Status = healthcheckPb.CheckStatus_ERROR
-			promClientCheck.FriendlyMessageToUser = fmt.Sprintf("Error calling Prometheus from the control plane: %s", err)
-		}
+	// TODO: viz: Enable this check once controller moves to viz
+	/*
+		if s.prometheusAPI != nil {
+			promClientCheck := &healthcheckPb.CheckResult{
+				SubsystemName:    promClientSubsystemName,
+				CheckDescription: promClientCheckDescription,
+				Status:           healthcheckPb.CheckStatus_OK,
+			}
+			_, err = s.queryProm(ctx, fmt.Sprintf(podQuery, ""))
+			if err != nil {
+				promClientCheck.Status = healthcheckPb.CheckStatus_ERROR
+				promClientCheck.FriendlyMessageToUser = fmt.Sprintf("Error calling Prometheus from the control plane: %s", err)
+			}
 
-		response.Results = append(response.Results, promClientCheck)
-	}
+			response.Results = append(response.Results, promClientCheck)
+		}
+	*/
 
 	return response, nil
 }

test/integration/install_test.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"fmt"
 	"os"
-	"strconv"
 	"strings"
 	"testing"
 	"time"
@@ -815,6 +814,10 @@ func TestInstallSP(t *testing.T) {
 	}
 }
 
+// This test fails because no web component is installed during this phase of
+// the extension split. It should be renabled after the issue below is closed.
+// Issue: https://github.com/linkerd/linkerd2/issues/5478
+/*
 func TestDashboard(t *testing.T) {
 	dashboardPort := 52237
 	dashboardURL := fmt.Sprintf("http://localhost:%d", dashboardPort)
@@ -851,6 +854,7 @@ func TestDashboard(t *testing.T) {
 			resp, TestHelper.GetVersion())
 	}
 }
+*/
 
 func TestInject(t *testing.T) {
 	resources, err := testutil.ReadFile("testdata/smoke_test.yaml")

test/integration/testdata/check.cni.golden

@@ -64,7 +64,6 @@ linkerd-api
 √ control plane pods are ready
 √ control plane self-check
 √ [kubernetes] control plane can talk to Kubernetes
-√ [prometheus] control plane can talk to Prometheus
 
 linkerd-version
 ---------------

test/integration/testdata/check.cni.proxy.golden

@@ -68,7 +68,6 @@ linkerd-api
 √ control plane pods are ready
 √ control plane self-check
 √ [kubernetes] control plane can talk to Kubernetes
-√ [prometheus] control plane can talk to Prometheus
 
 linkerd-version
 ---------------

test/integration/testdata/check.golden

@@ -52,7 +52,6 @@ linkerd-api
 √ control plane pods are ready
 √ control plane self-check
 √ [kubernetes] control plane can talk to Kubernetes
-√ [prometheus] control plane can talk to Prometheus
 
 linkerd-version
 ---------------

test/integration/testdata/check.multicluster.proxy.golden

@@ -56,7 +56,6 @@ linkerd-api
 √ control plane pods are ready
 √ control plane self-check
 √ [kubernetes] control plane can talk to Kubernetes
-√ [prometheus] control plane can talk to Prometheus
 
 linkerd-version
 ---------------

test/integration/testdata/check.proxy.golden

@@ -56,7 +56,6 @@ linkerd-api
 √ control plane pods are ready
 √ control plane self-check
 √ [kubernetes] control plane can talk to Kubernetes
-√ [prometheus] control plane can talk to Prometheus
 
 linkerd-version
 ---------------