Convert inventory transformer to plugin, reduce k8sdeps.

plugin/builtin/inventorytransformer/InventoryTransformer.go

@@ -0,0 +1,137 @@
+// Copyright 2019 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+//go:generate go run sigs.k8s.io/kustomize/plugin/pluginator
+package main
+
+import (
+	"fmt"
+	"strings"
+
+	"sigs.k8s.io/kustomize/pkg/resource"
+
+	"sigs.k8s.io/kustomize/pkg/hasher"
+	"sigs.k8s.io/kustomize/pkg/ifc"
+	"sigs.k8s.io/kustomize/pkg/inventory"
+	"sigs.k8s.io/kustomize/pkg/resid"
+	"sigs.k8s.io/kustomize/pkg/resmap"
+	"sigs.k8s.io/kustomize/pkg/types"
+	"sigs.k8s.io/yaml"
+)
+
+type plugin struct {
+	ldr       ifc.Loader
+	rf        *resmap.Factory
+	Policy    string `json:"policy,omitempty" yaml:"policy,omitempty"`
+	Name      string `json:"name,omitempty" yaml:"name,omitempty"`
+	Namespace string `json:"namespace,omitempty" yaml:"namespace,omitempty"`
+}
+
+var KustomizePlugin plugin
+
+func (p *plugin) Config(
+	ldr ifc.Loader, rf *resmap.Factory, c []byte) (err error) {
+	p.ldr = ldr
+	p.rf = rf
+	err = yaml.Unmarshal(c, p)
+	if err != nil {
+		return err
+	}
+	if p.Policy == "" {
+		p.Policy = types.GarbageIgnore.String()
+	}
+	if p.Policy != types.GarbageCollect.String() &&
+		p.Policy != types.GarbageIgnore.String() {
+		return fmt.Errorf(
+			"unrecognized garbagePolicy '%s'", p.Policy)
+	}
+	return nil
+}
+
+// Transform generates an inventory object from the input ResMap.
+// This ConfigMap supports the pruning command in
+// the client side tool proposed here:
+// https://github.com/kubernetes/enhancements/pull/810
+//
+// The inventory data is written to the ConfigMap's
+// annotations, rather than to the key-value pairs in
+// the ConfigMap's data field, since
+//   1. Keys in a ConfigMap's data field are too
+//      constrained for this purpose.
+//   2. Using annotations allow any object to be used,
+//      not just a ConfigMap, should some other object
+//      (e.g. some App object) become more desirable
+//      for this purpose.
+func (p *plugin) Transform(m resmap.ResMap) error {
+
+	inv, h, err := makeInventory(m)
+	if err != nil {
+		return err
+	}
+
+	args := types.ConfigMapArgs{}
+	args.Name = p.Name
+	args.Namespace = p.Namespace
+	opts := &types.GeneratorOptions{
+		Annotations: make(map[string]string),
+	}
+	opts.Annotations[inventory.HashAnnotation] = h
+	err = inv.UpdateAnnotations(opts.Annotations)
+	if err != nil {
+		return err
+	}
+
+	cm, err := p.rf.RF().MakeConfigMap(p.ldr, opts, &args)
+	if err != nil {
+		return err
+	}
+
+	if p.Policy == types.GarbageCollect.String() {
+		for byeBye := range m {
+			delete(m, byeBye)
+		}
+	}
+
+	id := cm.Id()
+	if _, ok := m[id]; ok {
+		return fmt.Errorf(
+			"id '%v' already used; use a different name", id)
+	}
+	m[id] = cm
+	return nil
+}
+
+func makeInventory(m resmap.ResMap) (
+	inv *inventory.Inventory, hash string, err error) {
+	inv = inventory.NewInventory()
+	var keys []string
+	for _, r := range m {
+		ns := getNamespace(r)
+		item := resid.NewItemId(r.GetGvk(), ns, r.GetName())
+		if _, ok := inv.Current[item]; ok {
+			return nil, "", fmt.Errorf(
+				"item '%v' already in inventory", item)
+		}
+		inv.Current[item] = computeRefs(r, m)
+		keys = append(keys, item.String())
+	}
+	h, err := hasher.SortArrayAndComputeHash(keys)
+	return inv, h, err
+}
+
+func getNamespace(r *resource.Resource) string {
+	ns, err := r.GetFieldValue("metadata.namespace")
+	if err != nil && !strings.Contains(err.Error(), "no field named") {
+		panic(err)
+	}
+	return ns
+}
+
+func computeRefs(r *resource.Resource, m resmap.ResMap) (refs []resid.ItemId) {
+	for _, refid := range r.GetRefBy() {
+		ref := m[refid]
+		ns := getNamespace(ref)
+		refs = append(refs, resid.NewItemId(ref.GetGvk(), ns, ref.GetName()))
+	}
+	return
+}