clusterapi: move envtest.kubeconfig to hidden dir

Prior to this commit, envtest.kubeconfig was placed in the auth
dir which contains the cluster kubeconfigs. Leaving the
envtest.kubeconfig in this dir may confuse users. Instead, let's
hide the kubeconfig in the capi artifacts directory.

Author: patrickdillon

pkg/clusterapi/localcontrolplane.go

@@ -107,10 +107,15 @@ func (c *localControlPlane) Run(ctx context.Context) error {
 		return err
 	}
 
+	artifactsDirPath := filepath.Join(command.RootOpts.Dir, ArtifactsDir)
+	err = os.MkdirAll(artifactsDirPath, 0750)
+	if err != nil {
+		return fmt.Errorf("error creating cluster-api artifacts directory: %w", err)
+	}
+
 	kc := fromEnvTestConfig(c.Cfg)
 	{
-		dir := filepath.Join(command.RootOpts.Dir, "auth")
-		kf, err := os.Create(filepath.Join(dir, "envtest.kubeconfig"))
+		kf, err := os.Create(filepath.Join(artifactsDirPath, "envtest.kubeconfig"))
 		if err != nil {
 			return err
 		}