From d975066f96a5f9caf8af8d513076480a33943257 Mon Sep 17 00:00:00 2001
From: Skye Gill <gill.skye95@gmail.com>
Date: Thu, 10 Nov 2022 10:22:01 +0000
Subject: [PATCH] fix: nil pointer dereference (#216)

Signed-off-by: Skye Gill <gill.skye95@gmail.com>

Signed-off-by: Skye Gill <gill.skye95@gmail.com>
---
 webhooks/pod_webhook.go      | 13 +++++++++----
 webhooks/pod_webhook_test.go | 19 +++++++++++++++++++
 2 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/webhooks/pod_webhook.go b/webhooks/pod_webhook.go
index 5cb7f5e99..97ebab20b 100644
--- a/webhooks/pod_webhook.go
+++ b/webhooks/pod_webhook.go
@@ -45,6 +45,12 @@ type PodMutator struct {
 
 // Handle injects the flagd sidecar (if the prerequisites are all met)
 func (m *PodMutator) Handle(ctx context.Context, req admission.Request) admission.Response {
+	defer func() {
+		if err := recover(); err != nil {
+			admission.Errored(http.StatusInternalServerError, fmt.Errorf("%v", err))
+		}
+	}()
+
 	pod := &corev1.Pod{}
 	err := m.decoder.Decode(req, pod)
 	if err != nil {
@@ -249,12 +255,11 @@ func (m *PodMutator) injectSidecar(pod *corev1.Pod, configMap string, featureFla
 		FlagDTag = os.Getenv("FLAGD_VERSION")
 	}
 
-	if featureFlag.Spec.FlagDSpec.MetricsPort != 0 {
-		flagdMetricsPort = featureFlag.Spec.FlagDSpec.MetricsPort
-	}
-
 	var envs []corev1.EnvVar
 	if featureFlag.Spec.FlagDSpec != nil {
+		if featureFlag.Spec.FlagDSpec.MetricsPort != 0 {
+			flagdMetricsPort = featureFlag.Spec.FlagDSpec.MetricsPort
+		}
 		envs = featureFlag.Spec.FlagDSpec.Envs
 	}
 
diff --git a/webhooks/pod_webhook_test.go b/webhooks/pod_webhook_test.go
index 9a8743478..cbe6a8be8 100644
--- a/webhooks/pod_webhook_test.go
+++ b/webhooks/pod_webhook_test.go
@@ -236,4 +236,23 @@ var _ = Describe("pod mutation webhook", func() {
 		err = k8sClient.Update(testCtx, ffConfig)
 		Expect(err).ShouldNot(HaveOccurred())
 	})
+
+	It("should not panic if flagDSpec isn't provided", func() {
+		ffConfigName := "feature-flag-configuration-panic-test"
+		ffConfig := &corev1alpha1.FeatureFlagConfiguration{}
+		ffConfig.Namespace = mutatePodNamespace
+		ffConfig.Name = ffConfigName
+		ffConfig.Spec.FeatureFlagSpec = featureFlagSpec
+		err := k8sClient.Create(testCtx, ffConfig)
+		Expect(err).ShouldNot(HaveOccurred())
+
+		pod := testPod()
+		pod.Annotations["openfeature.dev/featureflagconfiguration"] = ffConfigName
+		err = k8sClient.Create(testCtx, pod)
+		Expect(err).ShouldNot(HaveOccurred())
+
+		podMutationWebhookCleanup()
+		err = k8sClient.Delete(testCtx, ffConfig, client.GracePeriodSeconds(0))
+		Expect(err).ShouldNot(HaveOccurred())
+	})
 })