support for listing setters

kyaml/setters2/list.go

@@ -0,0 +1,117 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package setters2
+
+import (
+	"sort"
+	"strings"
+
+	"sigs.k8s.io/kustomize/kyaml/errors"
+	"sigs.k8s.io/kustomize/kyaml/kio"
+	"sigs.k8s.io/kustomize/kyaml/openapi"
+	"sigs.k8s.io/kustomize/kyaml/yaml"
+)
+
+// List lists the setters specified in the OpenAPI
+type List struct {
+	Name string
+
+	Setters []SetterDefinition
+}
+
+// List initializes l.Setters with the setters from the OpenAPI definitions in the file
+func (l *List) List(openAPIPath, resourcePath string) error {
+	if err := openapi.AddSchemaFromFile(openAPIPath); err != nil {
+		return err
+	}
+	y, err := yaml.ReadFile(openAPIPath)
+	if err != nil {
+		return err
+	}
+	return l.list(y, resourcePath)
+}
+
+func (l *List) list(object *yaml.RNode, resourcePath string) error {
+	// read the OpenAPI definitions
+	def, err := object.Pipe(yaml.LookupCreate(yaml.MappingNode, "openAPI", "definitions"))
+	if err != nil {
+		return err
+	}
+	if yaml.IsEmpty(def) {
+		return nil
+	}
+
+	// iterate over definitions -- find those that are setters
+	err = def.VisitFields(func(node *yaml.MapNode) error {
+		setter := SetterDefinition{}
+
+		// the definition key -- contains the setter name
+		key := node.Key.YNode().Value
+
+		if !strings.HasPrefix(key, SetterDefinitionPrefix) {
+			// not a setter -- doesn't have the right prefix
+			return nil
+		}
+
+		setterNode, err := node.Value.Pipe(yaml.Lookup(K8sCliExtensionKey, "setter"))
+		if err != nil {
+			return err
+		}
+		if yaml.IsEmpty(setterNode) {
+			// has the setter prefix, but missing the setter extension
+			return errors.Errorf("missing x-k8s-cli.setter for %s", key)
+		}
+
+		// unmarshal the yaml for the setter extension into the definition struct
+		b, err := setterNode.String()
+		if err != nil {
+			return err
+		}
+		if err := yaml.Unmarshal([]byte(b), &setter); err != nil {
+			return err
+		}
+
+		if l.Name != "" && l.Name != setter.Name {
+			// not the setter that was requested by list
+			return nil
+		}
+
+		// the description is not part of the extension, and should be pulled out
+		// separately from the extension values.
+		description := node.Value.Field("description")
+		if description != nil {
+			setter.Description = description.Value.YNode().Value
+		}
+
+		// count the number of fields set by this setter
+		setter.Count, err = l.count(resourcePath, setter.Name)
+		if err != nil {
+			return err
+		}
+
+		l.Setters = append(l.Setters, setter)
+		return nil
+	})
+	if err != nil {
+		return err
+	}
+
+	// sort the setters by their name
+	sort.Slice(l.Setters, func(i, j int) bool {
+		return l.Setters[i].Name < l.Setters[j].Name
+	})
+
+	return nil
+}
+
+// count returns the number of fields set by the setter with name
+func (l *List) count(path, name string) (int, error) {
+	s := &Set{Name: name}
+	err := kio.Pipeline{
+		Inputs:  []kio.Reader{&kio.LocalPackageReader{PackagePath: path}},
+		Filters: []kio.Filter{kio.FilterAll(s)},
+	}.Execute()
+
+	return s.Count, err
+}