Rename existing bootstrapper (#700)

Signed-off-by: Vince Prignano <vincepri@vmware.com>

cmd/clusterctl/clusterdeployer/bootstrap/existing/BUILD.bazel

@@ -2,14 +2,14 @@ load("@io_bazel_rules_go//go:def.bzl", "go_library", "go_test")
 
 go_library(
     name = "go_default_library",
-    srcs = ["existingcluster.go"],
+    srcs = ["cluster.go"],
     importpath = "sigs.k8s.io/cluster-api/cmd/clusterctl/clusterdeployer/bootstrap/existing",
     visibility = ["//visibility:public"],
     deps = ["//vendor/github.com/pkg/errors:go_default_library"],
 )
 
 go_test(
     name = "go_default_test",
-    srcs = ["existingcluster_test.go"],
+    srcs = ["cluster_test.go"],
     embed = [":go_default_library"],
 )

cmd/clusterctl/clusterdeployer/bootstrap/existing/existingcluster.go → cmd/clusterctl/clusterdeployer/bootstrap/existing/cluster.go

@@ -25,36 +25,36 @@ import (
 
 // Represents an existing cluster being used for bootstrapping, should not be able to
 // actually delete or create, but can point to actual kubeconfig file.
-type ExistingCluster struct {
+type Cluster struct {
 	kubeconfigPath string
 	kubeconfigFile string
 }
 
-// NewExistingCluster creates a new existing k8s bootstrap cluster object
+// New creates a new existing k8s bootstrap cluster object
 // We should clean up any lingering resources when clusterctl is complete.
 // TODO https://github.com/kubernetes-sigs/cluster-api/issues/448
-func NewExistingCluster(kubeconfigPath string) (*ExistingCluster, error) {
+func New(kubeconfigPath string) (*Cluster, error) {
 	if _, err := os.Stat(kubeconfigPath); os.IsNotExist(err) {
 		return nil, errors.Errorf("file at %s does not exist", kubeconfigPath)
 	}
 
-	return &ExistingCluster{kubeconfigPath: kubeconfigPath}, nil
+	return &Cluster{kubeconfigPath: kubeconfigPath}, nil
 }
 
 // Create implements clusterdeployer.ClusterProvisioner interface
-func (e *ExistingCluster) Create() error {
+func (e *Cluster) Create() error {
 	// noop
 	return nil
 }
 
 // Delete implements clusterdeployer.ClusterProvisioner interface
-func (e *ExistingCluster) Delete() error {
+func (e *Cluster) Delete() error {
 	// noop
 	return nil
 }
 
 // GetKubeconfig implements clusterdeployer.ClusterProvisioner interface
-func (e *ExistingCluster) GetKubeconfig() (string, error) {
+func (e *Cluster) GetKubeconfig() (string, error) {
 
 	if e.kubeconfigFile == "" {
 		b, err := ioutil.ReadFile(e.kubeconfigPath)

cmd/clusterctl/clusterdeployer/bootstrap/existing/existingcluster_test.go → cmd/clusterctl/clusterdeployer/bootstrap/existing/cluster_test.go

@@ -31,15 +31,15 @@ func TestGetKubeconfig(t *testing.T) {
 	defer os.Remove(f)
 
 	t.Run("invalid path given", func(t *testing.T) {
-		_, err = NewExistingCluster("")
+		_, err = New("")
 		if err == nil {
 			t.Fatal("Should not be able create External Cluster Provisioner.")
 		}
 	})
 
 	t.Run("file exists", func(t *testing.T) {
 
-		ec, err := NewExistingCluster(f)
+		ec, err := New(f)
 		if err != nil {
 			t.Fatal("Should be able create External Cluster Provisioner.")
 		}

cmd/clusterctl/clusterdeployer/bootstrap/provisioner.go

@@ -38,7 +38,7 @@ func Get(o Options) (ClusterProvisioner, error) {
 		return minikube.WithOptions(o.ExtraFlags), nil
 	default:
 		if o.KubeConfig != "" {
-			return existing.NewExistingCluster(o.KubeConfig)
+			return existing.New(o.KubeConfig)
 		}
 
 		return nil, errors.New("no bootstrap provisioner specified, you can specify `--bootstrap-cluster-kubeconfig` to use an existing Kubernetes cluster or `--bootstrap-type` to use a built-in ephemeral cluster.")