validate deploy_type on startup (fixes #32) (#33)

Co-authored-by: Chen Anidam <chen.anidam@catonetworks.com>

go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/onsi/gomega v1.28.0
 	github.com/prometheus/client_golang v1.17.0
 	github.com/rs/zerolog v1.31.0
+	k8s.io/apimachinery v0.28.2
 	k8s.io/client-go v0.28.2
 )
 
@@ -55,7 +56,6 @@ require (
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.1 // indirect
 	k8s.io/api v0.28.2 // indirect
-	k8s.io/apimachinery v0.28.2 // indirect
 	k8s.io/klog/v2 v2.100.1 // indirect
 	k8s.io/kube-openapi v0.0.0-20231010175941-2dd684a91f00 // indirect
 	k8s.io/utils v0.0.0-20230726121419-3b25d923346b // indirect

main.go

@@ -245,6 +245,10 @@ func main() {
 	port := getEnv("METRICS_PORT", "9100")
 	adjustedPollingRate, _ = strconv.ParseBool(getEnv("ADJUSTED_POLLING_RATE", "false"))
 	deployType = getEnv("DEPLOY_TYPE", "DaemonSet")
+	if deployType != "Deployment" && deployType != "DaemonSet" {
+		log.Error().Msg(fmt.Sprintf("deployType must be 'Deployment' or 'DaemonSet', got %s", deployType))
+		os.Exit(1)
+	}
 	http.Handle("/metrics", promhttp.Handler())
 	log.Info().Msg(fmt.Sprintf("Starting server listening on :%s", port))
 	err := http.ListenAndServe(fmt.Sprintf(":%s", port), nil)