seamless upgrades cli flag + kubeletplugin yaml accounts for updateStrategy values

Author: alimaazamat

cmd/dra-example-kubeletplugin/driver.go

@@ -61,8 +61,8 @@ func NewDriver(ctx context.Context, config *Config) (*driver, error) {
 		kubeletplugin.PluginDataDirectoryPath(config.DriverPluginPath()),
 	}
 
-	// Enable seamless upgrades when POD_UID is available (which gets set by Helm when seamlessUpgrades.enabled=true)
-	if config.flags.podUID != "" {
+	// Enable seamless upgrades when both seamless upgrades are enabled and POD_UID is available
+	if config.flags.seamlessUpgrades && config.flags.podUID != "" {
 		kubeletPluginOptions = append(kubeletPluginOptions,
 			kubeletplugin.RollingUpdate(types.UID(config.flags.podUID)),
 		)

cmd/dra-example-kubeletplugin/health.go

@@ -64,7 +64,7 @@ func startHealthcheck(ctx context.Context, config *Config) (*healthcheck, error)
 	regSockPath := (&url.URL{
 		Scheme: "unix",
 		Path: func() string {
-			if config.flags.podUID != "" {
+			if config.flags.seamlessUpgrades && config.flags.podUID != "" {
 				return path.Join(config.flags.kubeletRegistrarDirectoryPath, consts.DriverName+"-"+config.flags.podUID+"-reg.sock")
 			}
 			return path.Join(config.flags.kubeletRegistrarDirectoryPath, consts.DriverName+"-reg.sock")
@@ -82,7 +82,7 @@ func startHealthcheck(ctx context.Context, config *Config) (*healthcheck, error)
 	draSockPath := (&url.URL{
 		Scheme: "unix",
 		Path: func() string {
-			if config.flags.podUID != "" {
+			if config.flags.seamlessUpgrades && config.flags.podUID != "" {
 				return path.Join(config.DriverPluginPath(), "dra-"+config.flags.podUID+".sock")
 			}
 			return path.Join(config.DriverPluginPath(), "dra.sock")

cmd/dra-example-kubeletplugin/main.go

@@ -50,6 +50,7 @@ type Flags struct {
 	kubeletPluginsDirectoryPath   string
 	healthcheckPort               int
 	podUID                        string
+	seamlessUpgrades              bool
 }
 
 type Config struct {
@@ -122,6 +123,12 @@ func newApp() *cli.App {
 			Destination: &flags.podUID,
 			EnvVars:     []string{"POD_UID"},
 		},
+		&cli.BoolFlag{
+			Name:        "seamless-upgrades",
+			Usage:       "Enable seamless upgrades support. When enabled, the driver will use rolling update mode if pod-uid is available.",
+			Destination: &flags.seamlessUpgrades,
+			EnvVars:     []string{"SEAMLESS_UPGRADES"},
+		},
 	}
 	cliFlags = append(cliFlags, flags.kubeClientConfig.Flags()...)
 	cliFlags = append(cliFlags, flags.loggingConfig.Flags()...)

deployments/helm/dra-example-driver/templates/kubeletplugin.yaml

@@ -12,16 +12,16 @@ spec:
     matchLabels:
       {{- include "dra-example-driver.selectorLabels" . | nindent 6 }}
       app.kubernetes.io/component: kubeletplugin
+  {{- with .Values.kubeletPlugin.updateStrategy }}
+  updateStrategy:
+    {{- toYaml . | nindent 4 }}
+  {{- else }}
   {{- if .Values.kubeletPlugin.seamlessUpgrades.enabled }}
   updateStrategy:
     type: RollingUpdate
     rollingUpdate:
       maxSurge: 1
       maxUnavailable: 0
-  {{- else }}
-  {{- with .Values.kubeletPlugin.updateStrategy }}
-  updateStrategy:
-    {{- toYaml . | nindent 4 }}
   {{- end }}
   {{- end }}
   template:
@@ -88,11 +88,13 @@ spec:
         - name: HEALTHCHECK_PORT
           value: {{ .Values.kubeletPlugin.containers.plugin.healthcheckPort | quote }}
         {{- end }}
-        {{- if .Values.kubeletPlugin.seamlessUpgrades.enabled }}
         - name: POD_UID
           valueFrom:
             fieldRef:
               fieldPath: metadata.uid
+        {{- if .Values.kubeletPlugin.seamlessUpgrades.enabled }}
+        - name: SEAMLESS_UPGRADES
+          value: "true"
         {{- end }}
         volumeMounts:
         - name: plugins-registry