From d949ba6806a477c4034e0ce6160da4660f0c021b Mon Sep 17 00:00:00 2001
From: James Sturtevant <jsturtevant@gmail.com>
Date: Mon, 23 Sep 2024 15:57:20 -0700
Subject: [PATCH] Add ability to configure QPS and Burst for go-client

Signed-off-by: James Sturtevant <jsturtevant@gmail.com>
---
 admission-webhook/main.go             | 38 +++++++++++++++++++--------
 charts/gmsa/templates/deployment.yaml |  4 +++
 charts/gmsa/values.yaml               |  2 ++
 3 files changed, 33 insertions(+), 11 deletions(-)

diff --git a/admission-webhook/main.go b/admission-webhook/main.go
index c04a4dd0..fb6a99ab 100644
--- a/admission-webhook/main.go
+++ b/admission-webhook/main.go
@@ -29,10 +29,7 @@ func main() {
 		keyPath: env("TLS_KEY"),
 	}
 
-	port, err := port("HTTPS_PORT")
-	if err != nil {
-		panic(err)
-	}
+	port := env_int("HTTPS_PORT", 443)
 
 	if err = webhook.start(port, tlsConfig, nil); err != nil {
 		panic(err)
@@ -83,19 +80,38 @@ func createKubeClient() (*kubeClient, error) {
 		return nil, err
 	}
 
+	config.QPS = env_float("QPS", rest.DefaultQPS)
+	config.Burst = env_int("BURST", rest.DefaultBurst)
+	logrus.Infof("QPS: %f, Burst: %d", config.QPS, config.Burst)
+
 	return newKubeClient(config)
 }
 
+func env_float(key string, defaultFloat float32) float32 {
+	if v, found := os.LookupEnv(key); found {
+		if i, err := strconv.ParseFloat(v, 32); err != nil {
+			return float32(i)
+		}
+		logrus.Warningf("unable to parse environment variable %s; using default value %f", key, defaultFloat)
+	}
+
+	return defaultFloat
+}
+
+func env_int(key string, defaultInt int) int {
+	if v, found := os.LookupEnv(key); found {
+		if i, err := strconv.Atoi(v); err != nil {
+			return i
+		}
+		logrus.Warningf("unable to parse environment variable %s; using default value %d", key, defaultInt)
+	}
+
+	return defaultInt
+}
+
 func env(key string) string {
 	if value, found := os.LookupEnv(key); found {
 		return value
 	}
 	panic(fmt.Errorf("%s env var not found", key))
 }
-
-func port(key string) (int, error) {
-	if port, found := os.LookupEnv(key); found {
-		return strconv.Atoi(port)
-	}
-	return 443, nil
-}
diff --git a/charts/gmsa/templates/deployment.yaml b/charts/gmsa/templates/deployment.yaml
index f171181c..3eebd509 100644
--- a/charts/gmsa/templates/deployment.yaml
+++ b/charts/gmsa/templates/deployment.yaml
@@ -53,6 +53,10 @@ spec:
               value: /tls/crt
             - name: HTTPS_PORT
               value: "{{ .Values.containerPort }}"
+            - name: BURST
+              value: "{{ .Values.burst }}"
+            - name: QPS
+              value: "{{ .Values.qps }}"
           {{- if .Values.securityContext }}
           securityContext: {{ toYaml .Values.securityContext | nindent 12 }}
           {{- end }}
diff --git a/charts/gmsa/values.yaml b/charts/gmsa/values.yaml
index 55c381ae..0aa4fe0d 100644
--- a/charts/gmsa/values.yaml
+++ b/charts/gmsa/values.yaml
@@ -49,3 +49,5 @@ podSecurityContext: {}
 replicaCount: 2
 securityContext: {}
 tolerations: []
+qps: 30
+burst: 50