fix: Add cluster reachability check before executing commands

Signed-off-by: Justin Toh <tohjustin@hotmail.com>

internal/client/client.go

@@ -35,6 +35,7 @@ type ListOptions struct {
 }
 
 type Interface interface {
+	IsReachable() error
 	ResolveAPIResource(s string) (*APIResource, error)
 	Get(ctx context.Context, name string, opts GetOptions) (*unstructuredv1.Unstructured, error)
 	List(ctx context.Context, opts ListOptions) (*unstructuredv1.UnstructuredList, error)
@@ -80,6 +81,12 @@ func (f *Flags) ToClient() (Interface, error) {
 	return cli, nil
 }
 
+// IsReachable tests connectivity to the cluster.
+func (c *client) IsReachable() error {
+	_, err := c.discoveryClient.ServerVersion()
+	return err
+}
+
 func (c *client) ResolveAPIResource(s string) (*APIResource, error) {
 	var gvr schema.GroupVersionResource
 	var gvk schema.GroupVersionKind

pkg/cmd/helm/helm.go

@@ -49,7 +49,7 @@ var (
 
 // CmdOptions contains all the options for running the helm command.
 type CmdOptions struct {
-	// RequestRelease represents the requested release
+	// RequestRelease represents the requested Helm release.
 	RequestRelease string
 
 	HelmDriver   string
@@ -109,10 +109,9 @@ func NewCmd(streams genericclioptions.IOStreams, name, parentCmdPath string) *co
 // Complete completes all the required options for command.
 func (o *CmdOptions) Complete(cmd *cobra.Command, args []string) error {
 	var err error
-	var rlsName string
 	switch len(args) {
 	case 1:
-		rlsName = args[0]
+		o.RequestRelease = args[0]
 	default:
 		return fmt.Errorf("release name must be specified\nSee '%s -h' for help and examples", cmdPath)
 	}
@@ -133,9 +132,6 @@ func (o *CmdOptions) Complete(cmd *cobra.Command, args []string) error {
 		return err
 	}
 
-	// Resolve command arguments
-	o.RequestRelease = rlsName
-
 	// Setup printer
 	o.ToPrinter = func(withGroup bool, withNamespace bool) (printers.ResourcePrinterFunc, error) {
 		printFlags := o.PrintFlags.Copy()
@@ -166,6 +162,10 @@ func (o *CmdOptions) Validate() error {
 		return fmt.Errorf("release NAME must be specified")
 	}
 
+	if o.Client == nil {
+		return fmt.Errorf("client must be provided")
+	}
+
 	klog.V(4).Infof("Namespace: %s", o.Namespace)
 	klog.V(4).Infof("RequestRelease: %v", o.RequestRelease)
 	klog.V(4).Infof("Flags.AllNamespaces: %t", *o.Flags.AllNamespaces)
@@ -176,17 +176,20 @@ func (o *CmdOptions) Validate() error {
 	klog.V(4).Infof("PrintFlags.NoHeaders: %t", *o.PrintFlags.HumanReadableFlags.NoHeaders)
 	klog.V(4).Infof("PrintFlags.ShowGroup: %t", *o.PrintFlags.HumanReadableFlags.ShowGroup)
 	klog.V(4).Infof("PrintFlags.ShowLabels: %t", *o.PrintFlags.HumanReadableFlags.ShowLabels)
-	klog.V(4).Infof("PrintFlags.WithNamespace: %t", o.PrintFlags.HumanReadableFlags.WithNamespace)
 
 	return nil
 }
 
 // Run implements all the necessary functionality for command.
 //nolint:funlen
 func (o *CmdOptions) Run() error {
-	var err error
 	ctx := context.Background()
 
+	// First check if Kubernetes cluster is reachable
+	if err := o.Client.IsReachable(); err != nil {
+		return err
+	}
+
 	// Fetch the release to ensure it exists before proceeding
 	helmClient := action.NewGet(o.ActionConfig)
 	rls, err := helmClient.Run(o.RequestRelease)
@@ -197,7 +200,7 @@ func (o *CmdOptions) Run() error {
 
 	// Fetch all Helm release objects (i.e. resources found in the helm release
 	// manifests) from the cluster
-	rlsObjs, err := o.getManifestObjects(rls)
+	rlsObjs, err := o.getManifestObjects(ctx, rls)
 	if err != nil {
 		return err
 	}
@@ -264,7 +267,7 @@ func (o *CmdOptions) Run() error {
 
 // getManifestObjects fetches all objects found in the manifest of the provided
 // Helm release.
-func (o *CmdOptions) getManifestObjects(rls *release.Release) ([]unstructuredv1.Unstructured, error) {
+func (o *CmdOptions) getManifestObjects(_ context.Context, rls *release.Release) ([]unstructuredv1.Unstructured, error) {
 	var objs []unstructuredv1.Unstructured
 	name, ns := rls.Name, rls.Namespace
 	r := strings.NewReader(rls.Manifest)

pkg/cmd/lineage/lineage.go

@@ -42,8 +42,10 @@ var (
 
 // CmdOptions contains all the options for running the lineage command.
 type CmdOptions struct {
-	// RequestObject represents the requested object.
-	RequestObject client.ObjectMeta
+	// RequestType represents the type of the requested object.
+	RequestType string
+	// RequestName represents the name of the requested object.
+	RequestName string
 
 	Flags     *Flags
 	Client    client.Interface
@@ -100,18 +102,17 @@ func NewCmd(streams genericclioptions.IOStreams, name, parentCmdPath string) *co
 // Complete completes all the required options for command.
 func (o *CmdOptions) Complete(cmd *cobra.Command, args []string) error {
 	var err error
-	var resourceType, resourceName string
 	switch len(args) {
 	case 1:
 		resourceTokens := strings.SplitN(args[0], "/", 2)
 		if len(resourceTokens) != 2 {
 			return fmt.Errorf("arguments in <resource>/<name> form must have a single resource and name\nSee '%s -h' for help and examples", cmdPath)
 		}
-		resourceType = resourceTokens[0]
-		resourceName = resourceTokens[1]
+		o.RequestType = resourceTokens[0]
+		o.RequestName = resourceTokens[1]
 	case 2:
-		resourceType = args[0]
-		resourceName = args[1]
+		o.RequestType = args[0]
+		o.RequestName = args[1]
 	default:
 		return fmt.Errorf("resource must be specified as <resource> <name> or <resource>/<name>\nSee '%s -h' for help and examples", cmdPath)
 	}
@@ -126,17 +127,6 @@ func (o *CmdOptions) Complete(cmd *cobra.Command, args []string) error {
 		return err
 	}
 
-	// Resolve command arguments
-	api, err := o.Client.ResolveAPIResource(resourceType)
-	if err != nil {
-		return err
-	}
-	o.RequestObject = client.ObjectMeta{
-		APIResource: *api,
-		Name:        resourceName,
-		Namespace:   o.Namespace,
-	}
-
 	// Setup printer
 	o.ToPrinter = func(withGroup bool, withNamespace bool) (printers.ResourcePrinterFunc, error) {
 		printFlags := o.PrintFlags.Copy()
@@ -163,18 +153,17 @@ func (o *CmdOptions) Complete(cmd *cobra.Command, args []string) error {
 
 // Validate validates all the required options for the lineage command.
 func (o *CmdOptions) Validate() error {
-	if len(o.RequestObject.Name) == 0 ||
-		o.RequestObject.GroupVersionResource().Empty() ||
-		o.RequestObject.GroupVersionKind().Empty() {
-		return fmt.Errorf("resource TYPE/NAME must be specified")
+	if len(o.RequestType) == 0 || len(o.RequestName) == 0 {
+		return fmt.Errorf("resource TYPE & NAME must be specified")
 	}
 
 	if o.Client == nil {
 		return fmt.Errorf("client must be provided")
 	}
 
 	klog.V(4).Infof("Namespace: %s", o.Namespace)
-	klog.V(4).Infof("RequestObject: %v", o.RequestObject)
+	klog.V(4).Infof("RequestType: %v", o.RequestType)
+	klog.V(4).Infof("RequestName: %v", o.RequestName)
 	klog.V(4).Infof("Flags.AllNamespaces: %t", *o.Flags.AllNamespaces)
 	klog.V(4).Infof("Flags.Scopes: %v", *o.Flags.Scopes)
 	klog.V(4).Infof("ClientFlags.Context: %s", *o.ClientFlags.Context)
@@ -191,9 +180,23 @@ func (o *CmdOptions) Validate() error {
 func (o *CmdOptions) Run() error {
 	ctx := context.Background()
 
+	// First check if Kubernetes cluster is reachable
+	if err := o.Client.IsReachable(); err != nil {
+		return err
+	}
+
 	// Fetch the provided object to ensure it exists before proceeding
-	root, err := o.Client.Get(ctx, o.RequestObject.Name, client.GetOptions{
-		APIResource: o.RequestObject.APIResource,
+	api, err := o.Client.ResolveAPIResource(o.RequestType)
+	if err != nil {
+		return err
+	}
+	obj := client.ObjectMeta{
+		APIResource: *api,
+		Name:        o.RequestName,
+		Namespace:   o.Namespace,
+	}
+	root, err := o.Client.Get(ctx, obj.Name, client.GetOptions{
+		APIResource: obj.APIResource,
 		Namespace:   o.Namespace,
 	})
 	if err != nil {