Pass context down

plugins/inputs/prometheus/kubernetes.go

@@ -38,7 +38,7 @@ func loadClient(kubeconfigPath string) (*k8s.Client, error) {
 	return k8s.NewClient(&config)
 }
 
-func start(p *Prometheus) error {
+func (p *Prometheus) start(ctx context.Context) error {
 	client, err := k8s.NewInClusterClient()
 	if err != nil {
 		u, err := user.Current()
@@ -55,7 +55,6 @@ func start(p *Prometheus) error {
 		}
 	}
 
-	p.ctx, p.cancel = context.WithCancel(context.Background())
 	p.wg = sync.WaitGroup{}
 	in := make(chan payload)
 
@@ -64,24 +63,23 @@ func start(p *Prometheus) error {
 		defer p.wg.Done()
 		for {
 			select {
-			case <-p.ctx.Done():
+			case <-ctx.Done():
 				break
 			case <-time.After(time.Second):
-				err := watch(p, client, in)
+				err := p.watch(ctx, client, in)
 				if err == nil {
 					break
 				}
 			}
 		}
-		log.Printf("D! [inputs.prometheus] shutting down")
 	}()
 
 	return nil
 }
 
-func watch(p *Prometheus, client *k8s.Client, in chan payload) error {
+func (p *Prometheus) watch(ctx context.Context, client *k8s.Client, in chan payload) error {
 	pod := &corev1.Pod{}
-	watcher, err := client.Watch(p.ctx, "", &corev1.Pod{})
+	watcher, err := client.Watch(ctx, "", &corev1.Pod{})
 	if err != nil {
 		log.Printf("E! [inputs.prometheus] unable to watch resources: %v", err)
 		return err
@@ -90,7 +88,7 @@ func watch(p *Prometheus, client *k8s.Client, in chan payload) error {
 
 	for {
 		select {
-		case <-p.ctx.Done():
+		case <-ctx.Done():
 			return nil
 		default:
 			pod = &corev1.Pod{}

plugins/inputs/prometheus/prometheus.go

@@ -43,7 +43,6 @@ type Prometheus struct {
 	MonitorPods    bool `toml:"monitor_kubernetes_pods"`
 	lock           sync.Mutex
 	kubernetesPods []URLAndAddress
-	ctx            context.Context
 	cancel         context.CancelFunc
 	wg             sync.WaitGroup
 }
@@ -264,7 +263,9 @@ func (p *Prometheus) gatherURL(u URLAndAddress, acc telegraf.Accumulator) error
 // Start will start the Kubernetes scraping if enabled in the configuration
 func (p *Prometheus) Start(a telegraf.Accumulator) error {
 	if p.MonitorPods {
-		return start(p)
+		var ctx context.Context
+		ctx, p.cancel = context.WithCancel(context.Background())
+		return p.start(ctx)
 	}
 	return nil
 }