From e4651743308e52ac4ca3808d26f2b65b434deb44 Mon Sep 17 00:00:00 2001
From: Niladri Halder <niladri.halder26@gmail.com>
Date: Mon, 29 May 2023 13:21:34 +0530
Subject: [PATCH] feat(provisioner): Expose Kubernetes client QPS and Burst as
 flags (#234) (#235)

* Expose Kubernetes client QPS and Burst as flags




* feat(operator-yaml): add flags for k8s client qps and burst



---------

Signed-off-by: Michael Morello <michael.morello@elastic.co>
Signed-off-by: Niladri Halder <niladri.halder26@gmail.com>
Co-authored-by: Michael Morello <michael.morello@elastic.co>
---
 cmd/main.go                 |  8 ++++++++
 deploy/lvm-operator.yaml    |  4 ++++
 pkg/driver/config/config.go |  6 ++++++
 pkg/driver/controller.go    | 10 ++++++++++
 4 files changed, 28 insertions(+)

diff --git a/cmd/main.go b/cmd/main.go
index d3d0e8c4..219a7ed5 100644
--- a/cmd/main.go
+++ b/cmd/main.go
@@ -98,6 +98,14 @@ func main() {
 		&config.DisableExporterMetrics, "disable-exporter-metrics", true, "Exclude metrics about the exporter itself (process_*, go_*).",
 	)
 
+	cmd.PersistentFlags().IntVar(
+		&config.KubeAPIQPS, "kube-api-qps", 0, "QPS to use while talking with Kubernetes API server.",
+	)
+
+	cmd.PersistentFlags().IntVar(
+		&config.KubeAPIBurst, "kube-api-burst", 0, "Burst to allow while talking with Kubernetes API server.",
+	)
+
 	config.RIopsLimitPerGB = cmd.PersistentFlags().StringSlice(
 		"riops-per-gb", []string{},
 		"Read IOPS per GB limit to use for each volume group prefix, "+
diff --git a/deploy/lvm-operator.yaml b/deploy/lvm-operator.yaml
index 2f3a27ed..f86be38d 100644
--- a/deploy/lvm-operator.yaml
+++ b/deploy/lvm-operator.yaml
@@ -1273,6 +1273,8 @@ spec:
           args :
             - "--endpoint=$(OPENEBS_CSI_ENDPOINT)"
             - "--plugin=$(OPENEBS_CONTROLLER_DRIVER)"
+            - "--kube-api-qps=0"
+            - "--kube-api-burst=0"
           volumeMounts:
             - name: socket-dir
               mountPath: /var/lib/csi/sockets/pluginproxy/
@@ -1460,6 +1462,8 @@ spec:
             - "--endpoint=$(OPENEBS_CSI_ENDPOINT)"
             - "--plugin=$(OPENEBS_NODE_DRIVER)"
             - "--listen-address=$(METRICS_LISTEN_ADDRESS)"
+            - "--kube-api-qps=0"
+            - "--kube-api-burst=0"
           env:
             - name: OPENEBS_NODE_ID
               valueFrom:
diff --git a/pkg/driver/config/config.go b/pkg/driver/config/config.go
index d353e11e..04a7a837 100644
--- a/pkg/driver/config/config.go
+++ b/pkg/driver/config/config.go
@@ -79,6 +79,12 @@ type Config struct {
 
 	// Exclude metrics about the exporter itself (process_*, go_*).
 	DisableExporterMetrics bool
+
+	// KubeAPIQPS is the QPS to use while talking with Kubernetes API server.
+	KubeAPIQPS int
+
+	// KubeAPIBurst is the burst to allow while talking with Kubernetes API server.
+	KubeAPIBurst int
 }
 
 // Default returns a new instance of config
diff --git a/pkg/driver/controller.go b/pkg/driver/controller.go
index 7287a3e8..0ce1c8b0 100644
--- a/pkg/driver/controller.go
+++ b/pkg/driver/controller.go
@@ -181,6 +181,16 @@ func (cs *controller) init() error {
 		return errors.Wrapf(err, "failed to build kubeconfig")
 	}
 
+	if cs.driver.config.KubeAPIQPS > 0 {
+		klog.Infof("setting k8s client qps to %d", cs.driver.config.KubeAPIQPS)
+		cfg.QPS = float32(cs.driver.config.KubeAPIQPS)
+	}
+
+	if cs.driver.config.KubeAPIBurst > 0 {
+		cfg.Burst = cs.driver.config.KubeAPIBurst
+		klog.Infof("setting k8s client burst to %d", cs.driver.config.KubeAPIBurst)
+	}
+
 	kubeClient, err := kubernetes.NewForConfig(cfg)
 	if err != nil {
 		return errors.Wrap(err, "failed to build k8s clientset")