feat: initial implementation of halkyon descriptor support

When hal runs to attempt to create an entity, it will gather all locally known
entities of that type by parsing any existing halkyon descriptors. hal will look
for descriptors as follows: halkyon.(yml|yaml) files in the current directory,
dekorate-generated descriptor for the current directory and look for the same
files in each of the current directory's child directories, not looking further
than one level deep. When descriptors are detected, the user is asked whether they
want to operate on the detected entities.

pkg/cmdutil/create.go

@@ -10,6 +10,8 @@ import (
 	v1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/client-go/tools/record/util"
+	"os"
+	"path/filepath"
 	"time"
 )
 
@@ -19,11 +21,13 @@ type Creator interface {
 	Runnable
 	GeneratePrefix() string
 	Build() runtime.Object
+	Set(entity runtime.Object)
 }
 
 type CreateOptions struct {
 	*GenericOperationOptions
-	Delegate Creator
+	Delegate       Creator
+	fromDescriptor bool
 }
 
 func NewCreateOptions(resourceType ResourceType, client HalkyonEntity) *CreateOptions {
@@ -37,14 +41,74 @@ func NewCreateOptions(resourceType ResourceType, client HalkyonEntity) *CreateOp
 	return c
 }
 
-func (o *CreateOptions) Complete(name string, cmd *cobra.Command, args []string) error {
-	if err := o.Delegate.Complete(name, cmd, args); err != nil {
-		return err
+func entityNames(registry entitiesRegistry) []string {
+	names := make([]string, 0, len(registry))
+	for _, entity := range registry {
+		names = append(names, entity.Name)
 	}
+	return names
+}
 
+func (o *CreateOptions) Complete(name string, cmd *cobra.Command, args []string) error {
 	if len(args) == 1 {
 		o.Name = args[0]
 	}
+
+	// look for locally existing components that also don't already exist on the remote cluster
+	currentDir, err := os.Getwd()
+	if err != nil {
+		return err
+	}
+	hd := LoadAvailableHalkyonEntities(currentDir)
+	entities := hd.GetDefinedEntitiesWith(o.ResourceType)
+	size := len(entities)
+	t := o.ResourceType.String()
+	if size > 0 {
+		// if we have an entity with the same name as the current directory, use it by default
+		currentDirName := filepath.Base(currentDir)
+		if entity, ok := entities[currentDirName]; ok {
+			o.Name = entity.Name
+			o.fromDescriptor = true
+			o.Delegate.Set(entity.Entity)
+		} else {
+			names := entityNames(entities)
+			if size == 1 {
+				if o.Name == names[0] {
+					entity := entities[o.Name]
+					if IsInteractive(cmd) && ui.Proceed(fmt.Sprintf("Found %s named %s in %s, use it", t, o.Name, entity.Path)) {
+						o.Name = entity.Name
+						o.fromDescriptor = true
+						o.Delegate.Set(entity.Entity)
+					}
+				}
+			} else if IsInteractive(cmd) && ui.Proceed(fmt.Sprintf("Found %d %s(s), do you want to %s from them", size, t, o.operationName)) {
+				o.Name = ui.Select(t, names, o.Name)
+			}
+		}
+
+	}
+
+	entity, ok := entities[o.Name]
+	if ok {
+		ui.OutputSelection(fmt.Sprintf("Selected %s from %s", t, entity.Path), o.Name)
+		o.fromDescriptor = true
+		// set the component on the delegate so it uses it when we want ask to create it
+		o.Delegate.Set(entity.Entity)
+		exists, err := o.Exists()
+		if err != nil {
+			return err
+		}
+		if exists {
+			return fmt.Errorf("a %s named '%s' already exists, please use update instead (NOT YET IMPLEMENTED)", o.ResourceType, o.Name)
+		}
+	}
+
+	if !o.fromDescriptor {
+		if err := o.Delegate.Complete(name, cmd, args); err != nil {
+			return err
+		}
+	}
+
 	for {
 		o.Name = ui.Ask("Name", o.Name, o.generateName())
 		err := validation.NameValidator(o.Name)
@@ -68,9 +132,23 @@ func (o *CreateOptions) Complete(name string, cmd *cobra.Command, args []string)
 	return nil
 }
 
+func (o *CreateOptions) Exists() (bool, error) {
+	err := o.Client.Get(o.Name, v1.GetOptions{})
+	if err != nil {
+		if util.IsKeyNotFoundError(errors.Cause(err)) {
+			return false, nil
+		} else {
+			return false, err
+		}
+	}
+	return true, nil
+}
+
 func (o *CreateOptions) Validate() error {
-	if err := o.Delegate.Validate(); err != nil {
-		return err
+	if !o.fromDescriptor {
+		if err := o.Delegate.Validate(); err != nil {
+			return err
+		}
 	}
 	return nil
 }

pkg/hal/cli/capability/create.go

@@ -22,6 +22,11 @@ type createOptions struct {
 	paramPairs  []string
 	parameters  []halkyon.NameValuePair
 	*cmdutil.CreateOptions
+	target *v1beta1.Capability
+}
+
+func (o *createOptions) Set(entity runtime.Object) {
+	o.target = entity.(*v1beta1.Capability)
 }
 
 var (

pkg/hal/cli/component/create.go

@@ -64,6 +64,7 @@ type createOptions struct {
 	Template  string
 	P         string
 	scaffoldP string
+	target    *v1beta1.Component
 }
 
 func (o *createOptions) GeneratePrefix() string {
@@ -92,6 +93,10 @@ func (o *createOptions) Build() runtime.Object {
 	}
 }
 
+func (o *createOptions) Set(entity runtime.Object) {
+	o.target = entity.(*v1beta1.Component)
+}
+
 var (
 	createExample = ktemplates.Examples(`  # Create a new Halkyon component located in the 'foo' child directory of the current directory
   %[1]s foo`)

pkg/hal/cli/link/create.go

@@ -24,6 +24,7 @@ type createOptions struct {
 	linkType   link.LinkType
 	*cmdutil.CreateOptions
 	*cmdutil.EnvOptions
+	target *link.Link
 }
 
 func (o *createOptions) SetEnvOptions(env *cmdutil.EnvOptions) {
@@ -106,6 +107,10 @@ func (o *createOptions) GeneratePrefix() string {
 	return o.targetName
 }
 
+func (o *createOptions) Set(entity runtime.Object) {
+	o.target = entity.(*link.Link)
+}
+
 func NewCmdCreate(parent string) *cobra.Command {
 	c := k8s.GetClient()
 	o := &createOptions{}