Merge pull request #862 from cpuguy83/node_helpers

node/nodeutil/client.go

@@ -0,0 +1,58 @@
+package nodeutil
+
+import (
+	"os"
+
+	"github.com/pkg/errors"
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/apimachinery/pkg/fields"
+	kubeinformers "k8s.io/client-go/informers"
+	"k8s.io/client-go/kubernetes"
+	"k8s.io/client-go/kubernetes/typed/coordination/v1beta1"
+	"k8s.io/client-go/rest"
+	"k8s.io/client-go/tools/clientcmd"
+)
+
+// ClientsetFromEnv returns a kuberentes client set from:
+// 1. the passed in kubeconfig path
+// 2. If the kubeconfig path is empty or non-existent, then the in-cluster config is used.
+func ClientsetFromEnv(kubeConfigPath string) (*kubernetes.Clientset, error) {
+	var (
+		config *rest.Config
+		err    error
+	)
+
+	if kubeConfigPath != "" {
+		if _, err := os.Stat(kubeConfigPath); err != nil {
+			config, err = rest.InClusterConfig()
+		} else {
+			config, err = clientcmd.NewNonInteractiveDeferredLoadingClientConfig(
+				&clientcmd.ClientConfigLoadingRules{ExplicitPath: kubeConfigPath},
+				nil,
+			).ClientConfig()
+		}
+	} else {
+		config, err = rest.InClusterConfig()
+	}
+
+	if err != nil {
+		return nil, errors.Wrap(err, "error getting rest client config")
+	}
+
+	return kubernetes.NewForConfig(config)
+}
+
+// PodInformerFilter is a filter that you should use when creating a pod informer for use with the pod controller.
+func PodInformerFilter(node string) kubeinformers.SharedInformerOption {
+	return kubeinformers.WithTweakListOptions(func(options *metav1.ListOptions) {
+		options.FieldSelector = fields.OneTermEqualSelector("spec.nodeName", node).String()
+	})
+}
+
+// NodeLeaseV1Beta1Client creates a v1beta1 Lease client for use with node leases from the passed in client.
+//
+// Use this with node.WithNodeEnableLeaseV1Beta1 when creating a node controller.
+func NodeLeaseV1Beta1Client(client kubernetes.Interface) v1beta1.LeaseInterface {
+	return client.CoordinationV1beta1().Leases(corev1.NamespaceNodeLease)
+}