Refactoring of "get instances" CLI command

pkg/kudoctl/cmd/get.go

@@ -5,15 +5,23 @@ import (
 	"github.com/spf13/cobra"
 )
 
-// newGetCmd creates a new command that lists instances
+// newGetCmd creates a command that lists the instances in the cluster
 func newGetCmd() *cobra.Command {
-	newCmd := &cobra.Command{
-		Use:   "get",
-		Short: "-> Show all available instances.",
-		Long:  `The get command has subcommands to show all available instances.`,
+	options := get.DefaultOptions
+	getCmd := &cobra.Command{
+		Use:   "get instances",
+		Short: "Gets all available instances.",
+		Long: `
+	# Get all available instances
+	kudoctl get instances`,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			// Prior to command execution we parse and validate passed parameters
+			return get.Run(args, options)
+		},
 	}
 
-	newCmd.AddCommand(get.NewGetInstancesCmd())
+	getCmd.Flags().StringVar(&options.KubeConfigPath, "kubeconfig", "", "The file path to kubernetes configuration file; defaults to $HOME/.kube/config")
+	getCmd.Flags().StringVar(&options.Namespace, "namespace", "default", "The namespace where the operator watches for changes.")
 
-	return newCmd
+	return getCmd
 }

pkg/kudoctl/cmd/get/get.go

@@ -0,0 +1,94 @@
+package get
+
+import (
+	"fmt"
+	"log"
+	"os"
+
+	"github.com/kudobuilder/kudo/pkg/kudoctl/util/kudo"
+	"github.com/pkg/errors"
+
+	"github.com/xlab/treeprint"
+	"k8s.io/client-go/tools/clientcmd"
+
+	"github.com/kudobuilder/kudo/pkg/kudoctl/util/check"
+)
+
+// Options defines configuration options for the get command
+type Options struct {
+	KubeConfigPath string
+	Namespace      string
+}
+
+// DefaultOptions initializes the get command options to its defaults
+var DefaultOptions = &Options{
+	Namespace: "default",
+}
+
+// Run returns the errors associated with cmd env
+func Run(args []string, options *Options) error {
+
+	err := validate(args, options)
+	if err != nil {
+		return err
+	}
+
+	kc, err := kudo.NewClient(options.Namespace, options.KubeConfigPath)
+	if err != nil {
+		return errors.Wrap(err, "creating kudo client")
+	}
+
+	p, err := getInstances(kc, options)
+	if err != nil {
+		log.Printf("Error: %v", err)
+	}
+	tree := treeprint.New()
+
+	for _, plan := range p {
+		tree.AddBranch(plan)
+	}
+	fmt.Printf("List of current installed instances in namespace \"%s\":\n", options.Namespace)
+	fmt.Println(tree.String())
+	return err
+}
+
+func validate(args []string, options *Options) error {
+	if len(args) != 1 {
+		return fmt.Errorf("expecting exactly one argument - \"instances\"")
+	}
+
+	if args[0] != "instances" {
+		return fmt.Errorf("expecting \"instances\" and not \"%s\"", args[0])
+	}
+
+	// If the $KUBECONFIG environment variable is set, use that
+	if len(os.Getenv("KUBECONFIG")) > 0 {
+		options.KubeConfigPath = os.Getenv("KUBECONFIG")
+	}
+
+	configPath, err := check.KubeConfigLocationOrDefault(options.KubeConfigPath)
+	if err != nil {
+		return fmt.Errorf("error when getting default kubeconfig path: %+v", err)
+	}
+	options.KubeConfigPath = configPath
+	if err := check.ValidateKubeConfigPath(options.KubeConfigPath); err != nil {
+		return errors.WithMessage(err, "could not check kubeconfig path")
+	}
+	_, err = clientcmd.BuildConfigFromFlags("", options.KubeConfigPath)
+	if err != nil {
+		return errors.Wrap(err, "getting config failed")
+	}
+
+	return nil
+
+}
+
+func getInstances(kc *kudo.Client, options *Options) ([]string, error) {
+
+	instanceList, err := kc.ListInstances(options.Namespace)
+	if err != nil {
+		return nil, errors.Wrap(err, "getting instances")
+	}
+
+	return instanceList, nil
+}

pkg/kudoctl/cmd/get/get_test.go

@@ -0,0 +1,109 @@
+package get
+
+import (
+	"testing"
+
+	"github.com/kudobuilder/kudo/pkg/apis/kudo/v1alpha1"
+	"github.com/kudobuilder/kudo/pkg/client/clientset/versioned/fake"
+	"github.com/kudobuilder/kudo/pkg/kudoctl/util/kudo"
+	v1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+)
+
+func TestValidate(t *testing.T) {
+	tests := []struct {
+		arg []string
+		opt Options
+		err string
+	}{
+		{nil, *DefaultOptions, "expecting exactly one argument - \"instances\""},                          // 1
+		{[]string{"arg", "arg2"}, *DefaultOptions, "expecting exactly one argument - \"instances\""},      // 2
+		{[]string{}, *DefaultOptions, "expecting exactly one argument - \"instances\""},                   // 3
+		{[]string{"somethingelse"}, *DefaultOptions, "expecting \"instances\" and not \"somethingelse\""}, // 4
+	}
+
+	for _, tt := range tests {
+		err := validate(tt.arg, DefaultOptions)
+		if err != nil {
+			if err.Error() != tt.err {
+				t.Errorf("Expecting error message '%s' but got '%s'", tt.err, err)
+			}
+		}
+	}
+}
+
+func newTestClient() *kudo.Client {
+	return kudo.NewClientFromK8s(fake.NewSimpleClientset())
+}
+
+func TestGetInstances(t *testing.T) {
+	testInstance := &v1alpha1.Instance{
+		TypeMeta: metav1.TypeMeta{
+			APIVersion: "kudo.k8s.io/v1alpha1",
+			Kind:       "Instance",
+		},
+		ObjectMeta: metav1.ObjectMeta{
+			Labels: map[string]string{
+				"controller-tools.k8s.io": "1.0",
+				"operator":                "test",
+			},
+			Name: "test",
+		},
+		Spec: v1alpha1.InstanceSpec{
+			OperatorVersion: v1.ObjectReference{
+				Name: "test-1.0",
+			},
+		},
+	}
+	tests := []struct {
+		arg       []string
+		opt       Options
+		err       string
+		instances []string
+	}{
+		{nil, *DefaultOptions, "expecting exactly one argument - \"instances\"", nil},                                   // 1
+		{[]string{"arg", "arg2"}, *DefaultOptions, "expecting exactly one argument - \"instances\"", nil},               // 2
+		{[]string{}, *DefaultOptions, "expecting exactly one argument - \"instances\"", nil},                            // 3
+		{[]string{"somethingelse"}, *DefaultOptions, "expecting \"instances\" and not \"somethingelse\"", nil},          // 4
+		{[]string{"instances"}, *DefaultOptions, "expecting \"instances\" and not \"somethingelse\"", []string{"test"}}, // 5
+	}
+
+	for i, tt := range tests {
+		kc := newTestClient()
+		kc.InstallInstanceObjToCluster(testInstance, "default")
+		instanceList, err := getInstances(kc, DefaultOptions)
+		if err != nil {
+			if err.Error() != tt.err {
+				t.Errorf("%d: Expecting error message '%s' but got '%s'", i+1, tt.err, err)
+			}
+		}
+		missing := compareSlice(tt.instances, instanceList)
+		for _, m := range missing {
+			t.Errorf("%d: Missed expected instance \"%v\"", i+1, m)
+		}
+	}
+}
+
+func compareSlice(real, mock []string) []string {
+	lm := len(mock)
+
+	var diff []string
+
+	for _, rv := range real {
+		i := 0
+		j := 0
+		for _, mv := range mock {
+			i++
+			if rv == mv {
+				continue
+			}
+			if rv != mv {
+				j++
+			}
+			if lm <= j {
+				diff = append(diff, rv)
+			}
+		}
+	}
+	return diff
+}

pkg/kudoctl/util/kudo/kudo.go

@@ -113,6 +113,20 @@ func (c *Client) InstanceExistsInCluster(name, namespace, version, instanceName
 	return true, nil
 }
 
+// ListInstances lists all instances of given operator installed in the cluster in a given ns
+func (c *Client) ListInstances(namespace string) ([]string, error) {
+	instances, err := c.clientset.KudoV1alpha1().Instances(namespace).List(v1.ListOptions{})
+	if err != nil {
+		return nil, err
+	}
+	existingInstances := []string{}
+
+	for _, v := range instances.Items {
+		existingInstances = append(existingInstances, v.Name)
+	}
+	return existingInstances, nil
+}
+
 // OperatorVersionsInstalled lists all the versions of given operator installed in the cluster in given ns
 func (c *Client) OperatorVersionsInstalled(operatorName, namespace string) ([]string, error) {
 	fv, err := c.clientset.KudoV1alpha1().OperatorVersions(namespace).List(v1.ListOptions{})