check nodes

discovery.go

@@ -0,0 +1,41 @@
+package main
+
+import (
+	"context"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes"
+)
+
+type Discovery interface {
+	Discover() ([]string, error)
+}
+
+type K8sDiscovery struct {
+	ctx    context.Context
+	client *kubernetes.Clientset
+}
+
+func (k *K8sDiscovery) Discover() ([]string, error) {
+	return k.DiscoverInNamespace("")
+}
+func (k *K8sDiscovery) DiscoverInNamespace(namespace string) ([]string, error) {
+	pods, err := k.client.CoreV1().Pods(namespace).List(k.ctx, metav1.ListOptions{
+		LabelSelector: "actor-pool=cart",
+	})
+	if err != nil {
+		return nil, err
+	}
+	hosts := make([]string, 0, len(pods.Items))
+	for _, pod := range pods.Items {
+		hosts = append(hosts, pod.Status.PodIP)
+	}
+	return hosts, nil
+}
+
+func NewK8sDiscovery(client *kubernetes.Clientset) *K8sDiscovery {
+	return &K8sDiscovery{
+		ctx:    context.Background(),
+		client: client,
+	}
+}