From d63c9422683c933d32dc9a55922850ab92f84957 Mon Sep 17 00:00:00 2001
From: Adrian Kostrubiak
 <72626345+adriankostrubiak-tomtom@users.noreply.github.com>
Date: Mon, 6 Dec 2021 06:37:56 -0500
Subject: [PATCH] add healthz, readyz probes to controller manager. (#603)

* add healthz, readyz probes to controller manager.

fixes #602

Signed-off-by: Adrian Kostrubiak adrian.kostrubiak@tomtom.com

* fix manager port

* run `make bundle' to update csv

* nitty change flag naming to be more consistent with existing flags

* fix import ordering
---
 ...emetry-operator.clusterserviceversion.yaml | 12 ++++++
 config/manager/manager.yaml                   | 12 ++++++
 main.go                                       | 37 +++++++++++++------
 3 files changed, 50 insertions(+), 11 deletions(-)

diff --git a/bundle/manifests/opentelemetry-operator.clusterserviceversion.yaml b/bundle/manifests/opentelemetry-operator.clusterserviceversion.yaml
index a022f288e1..9ec503968e 100644
--- a/bundle/manifests/opentelemetry-operator.clusterserviceversion.yaml
+++ b/bundle/manifests/opentelemetry-operator.clusterserviceversion.yaml
@@ -266,11 +266,23 @@ spec:
                 - --metrics-addr=127.0.0.1:8080
                 - --enable-leader-election
                 image: ghcr.io/open-telemetry/opentelemetry-operator/opentelemetry-operator:v0.40.0
+                livenessProbe:
+                  httpGet:
+                    path: /healthz
+                    port: 8081
+                  initialDelaySeconds: 15
+                  periodSeconds: 20
                 name: manager
                 ports:
                 - containerPort: 9443
                   name: webhook-server
                   protocol: TCP
+                readinessProbe:
+                  httpGet:
+                    path: /readyz
+                    port: 8081
+                  initialDelaySeconds: 5
+                  periodSeconds: 10
                 resources:
                   limits:
                     cpu: 200m
diff --git a/config/manager/manager.yaml b/config/manager/manager.yaml
index fbb8654ddc..4057084d49 100644
--- a/config/manager/manager.yaml
+++ b/config/manager/manager.yaml
@@ -27,6 +27,18 @@ spec:
         - --enable-leader-election
         image: controller
         name: manager
+        livenessProbe:
+          httpGet:
+            path: /healthz
+            port: 8081
+          initialDelaySeconds: 15
+          periodSeconds: 20
+        readinessProbe:
+          httpGet:
+            path: /readyz
+            port: 8081
+          initialDelaySeconds: 5
+          periodSeconds: 10
         resources:
           limits:
             cpu: 200m
diff --git a/main.go b/main.go
index f70438c099..e09f8928f2 100644
--- a/main.go
+++ b/main.go
@@ -30,6 +30,7 @@ import (
 	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/cache"
+	"sigs.k8s.io/controller-runtime/pkg/healthz"
 	"sigs.k8s.io/controller-runtime/pkg/log/zap"
 	"sigs.k8s.io/controller-runtime/pkg/manager"
 	"sigs.k8s.io/controller-runtime/pkg/webhook"
@@ -68,12 +69,16 @@ func main() {
 	v := version.Get()
 
 	// add flags related to this operator
-	var metricsAddr string
-	var enableLeaderElection bool
-	var collectorImage string
-	var targetAllocatorImage string
-	var autoInstrumentationJava string
+	var (
+		metricsAddr             string
+		probeAddr               string
+		enableLeaderElection    bool
+		collectorImage          string
+		targetAllocatorImage    string
+		autoInstrumentationJava string
+	)
 	pflag.StringVar(&metricsAddr, "metrics-addr", ":8080", "The address the metric endpoint binds to.")
+	flag.StringVar(&probeAddr, "health-probe-addr", ":8081", "The address the probe endpoint binds to.")
 	pflag.BoolVar(&enableLeaderElection, "enable-leader-election", false,
 		"Enable leader election for controller manager. "+
 			"Enabling this will ensure there is only one active controller manager.")
@@ -124,12 +129,13 @@ func main() {
 	}
 
 	mgrOptions := ctrl.Options{
-		Scheme:             scheme,
-		MetricsBindAddress: metricsAddr,
-		Port:               9443,
-		LeaderElection:     enableLeaderElection,
-		LeaderElectionID:   "9f7554c3.opentelemetry.io",
-		Namespace:          watchNamespace,
+		Scheme:                 scheme,
+		MetricsBindAddress:     metricsAddr,
+		Port:                   9443,
+		HealthProbeBindAddress: probeAddr,
+		LeaderElection:         enableLeaderElection,
+		LeaderElectionID:       "9f7554c3.opentelemetry.io",
+		Namespace:              watchNamespace,
 	}
 
 	if strings.Contains(watchNamespace, ",") {
@@ -206,6 +212,15 @@ func main() {
 	}
 	// +kubebuilder:scaffold:builder
 
+	if err := mgr.AddHealthzCheck("healthz", healthz.Ping); err != nil {
+		setupLog.Error(err, "unable to set up health check")
+		os.Exit(1)
+	}
+	if err := mgr.AddReadyzCheck("readyz", healthz.Ping); err != nil {
+		setupLog.Error(err, "unable to set up ready check")
+		os.Exit(1)
+	}
+
 	setupLog.Info("starting manager")
 	if err := mgr.Start(ctrl.SetupSignalHandler()); err != nil {
 		setupLog.Error(err, "problem running manager")