From d1d9340fba0d54e880ddfb1adff9796c1b934451 Mon Sep 17 00:00:00 2001
From: Khurram Baig <kbaig@redhat.com>
Date: Mon, 10 Feb 2020 23:48:07 +0530
Subject: [PATCH] Add Liveness Probe for EventListener Deployment

Add a Liveness Probe for EventListener Deployment at URL /live
---
 .errcheck.txt                                 |  1 +
 cmd/eventlistenersink/main.go                 |  5 +++++
 config/controller.yaml                        |  4 +++-
 .../v1alpha1/eventlistener/eventlistener.go   | 17 ++++++++++++++
 .../eventlistener/eventlistener_test.go       | 22 +++++++++++++++++++
 5 files changed, 48 insertions(+), 1 deletion(-)

diff --git a/.errcheck.txt b/.errcheck.txt
index 64671e21f..aaadf1279 100644
--- a/.errcheck.txt
+++ b/.errcheck.txt
@@ -2,6 +2,7 @@
 flag.Set
 os.Setenv
 logger.Sync
+fmt.Fprint
 fmt.Fprintf
 fmt.Fprintln
 (io.Closer).Close
diff --git a/cmd/eventlistenersink/main.go b/cmd/eventlistenersink/main.go
index 781d4fed0..2c7604ee6 100644
--- a/cmd/eventlistenersink/main.go
+++ b/cmd/eventlistenersink/main.go
@@ -97,5 +97,10 @@ func main() {
 	// Listen and serve
 	logger.Infof("Listen and serve on port %s", sinkArgs.Port)
 	http.HandleFunc("/", r.HandleEvent)
+	// For handling Liveness Probe
+	http.HandleFunc("/live", func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(200)
+		fmt.Fprint(w, "ok")
+	})
 	logger.Fatal(http.ListenAndServe(fmt.Sprintf(":%s", sinkArgs.Port), nil))
 }
diff --git a/config/controller.yaml b/config/controller.yaml
index ee51a6629..060f76f40 100644
--- a/config/controller.yaml
+++ b/config/controller.yaml
@@ -45,7 +45,9 @@ spec:
           "-logtostderr",
           "-stderrthreshold", "INFO",
           "-el-image", "github.com/tektoncd/triggers/cmd/eventlistenersink",
-          "-el-port", "8080"
+          "-el-port", "8080",
+          "-period-seconds", "10",
+          "-failure-threshold", "1"
         ]
         volumeMounts:
         - name: config-logging
diff --git a/pkg/reconciler/v1alpha1/eventlistener/eventlistener.go b/pkg/reconciler/v1alpha1/eventlistener/eventlistener.go
index 045b5fed4..a8cc5ae33 100644
--- a/pkg/reconciler/v1alpha1/eventlistener/eventlistener.go
+++ b/pkg/reconciler/v1alpha1/eventlistener/eventlistener.go
@@ -64,6 +64,12 @@ var (
 	// ElPort defines the port for the EventListener to listen on
 	ElPort = flag.Int("el-port", 8080,
 		"The container port for the EventListener to listen on.")
+	// PeriodSeconds defines Period Seconds for the EventListener Liveness Probe
+	PeriodSeconds = flag.Int("period-seconds", 10,
+		"The Period Seconds for the EventListener Liveness Probe.")
+	// FailureThreshold defines the Failure Threshold for the EventListener Liveness Probe
+	FailureThreshold = flag.Int("failure-threshold", 1,
+		"The Failure Threshold for the EventListener Liveness Probe.")
 	// StaticResourceLabels is a map with all the labels that should be on
 	// all resources generated by the EventListener
 	StaticResourceLabels = map[string]string{
@@ -260,6 +266,17 @@ func (c *Reconciler) reconcileDeployment(el *v1alpha1.EventListener) error {
 			ContainerPort: int32(*ElPort),
 			Protocol:      corev1.ProtocolTCP,
 		}},
+		LivenessProbe: &corev1.Probe{
+			Handler: corev1.Handler{
+				HTTPGet: &corev1.HTTPGetAction{
+					Path:   "/live",
+					Scheme: corev1.URISchemeHTTP,
+					Port:   intstr.FromInt((*ElPort)),
+				},
+			},
+			PeriodSeconds:    int32(*PeriodSeconds),
+			FailureThreshold: int32(*FailureThreshold),
+		},
 		Args: []string{
 			"-el-name", el.Name,
 			"-el-namespace", el.Namespace,
diff --git a/pkg/reconciler/v1alpha1/eventlistener/eventlistener_test.go b/pkg/reconciler/v1alpha1/eventlistener/eventlistener_test.go
index 68ac4f315..efb20c64b 100644
--- a/pkg/reconciler/v1alpha1/eventlistener/eventlistener_test.go
+++ b/pkg/reconciler/v1alpha1/eventlistener/eventlistener_test.go
@@ -284,6 +284,17 @@ func Test_reconcileDeployment(t *testing.T) {
 									Protocol:      corev1.ProtocolTCP,
 								},
 							},
+							LivenessProbe: &corev1.Probe{
+								Handler: corev1.Handler{
+									HTTPGet: &corev1.HTTPGetAction{
+										Path:   "/live",
+										Scheme: corev1.URISchemeHTTP,
+										Port:   intstr.FromInt((*ElPort)),
+									},
+								},
+								PeriodSeconds:    int32(*PeriodSeconds),
+								FailureThreshold: int32(*FailureThreshold),
+							},
 							Args: []string{
 								"-el-name", eventListenerName,
 								"-el-namespace", namespace,
@@ -541,6 +552,17 @@ func TestReconcile(t *testing.T) {
 							ContainerPort: int32(*ElPort),
 							Protocol:      corev1.ProtocolTCP,
 						}},
+						LivenessProbe: &corev1.Probe{
+							Handler: corev1.Handler{
+								HTTPGet: &corev1.HTTPGetAction{
+									Path:   "/live",
+									Scheme: corev1.URISchemeHTTP,
+									Port:   intstr.FromInt((*ElPort)),
+								},
+							},
+							PeriodSeconds:    int32(*PeriodSeconds),
+							FailureThreshold: int32(*FailureThreshold),
+						},
 						Args: []string{
 							"-el-name", eventListenerName,
 							"-el-namespace", namespace,