memory is cool

Author: jnewland

main.go

@@ -29,8 +29,22 @@ import (
 nodeutil "k8s.io/kubernetes/pkg/api/v1/node"
 )
 
-func setLed(key string) error {
+// LED contains the state of the NUC's LED
+type LED struct {
+state string
+}
+
+// SetState updates the value of the LED.
+func (led *LED) SetState(key string) error {
 value := os.Getenv(fmt.Sprintf("NUC_LED_%s", strings.ToUpper(key)))
+if led.state != value {
+return led.writeState(value)
+}
+return nil
+}
+
+func (led *LED) writeState(value string) error {
+led.state = value
 bytes := []byte(value)
 log.Printf("Setting NUC LED to: %s", value)
 return ioutil.WriteFile("/proc/acpi/nuc_led", bytes, 0644)
@@ -49,19 +63,21 @@ func main() {
 
 fmt.Printf("greetings\n")
 
+led := &LED{}
+
 for {
 node, err := clientset.CoreV1().Nodes().Get(os.Getenv("NODE_NAME"), metav1.GetOptions{})
 if err != nil {
-setLed("error")
+led.SetState("error")
 } else {
 if nodeutil.IsNodeReady(node) {
 if node.Spec.Unschedulable == true {
-setLed("unschedulable")
+led.SetState("unschedulable")
 } else {
-setLed("ready")
+led.SetState("ready")
 }
 } else {
-setLed("not_ready")
+led.SetState("not_ready")
 }
 }
 time.Sleep(10 * time.Second)