Merge pull request #5 from kaweezle/feature/kpt-compatible

♻️ make function kpt compatible

README.md

@@ -19,8 +19,9 @@ transformation in your kustomize projects.
     <li><a href="#keeping-or-deleting-generated-resources">Keeping or deleting generated resources</a></li>
     <li><a href="#extensions">Extensions</a>
         <ul>
-            <li><a href="#heredoc-generator">Heredoc generator</a></li>
+            <li><a href="#remove-transformer">Remove Transformer</a></li>
             <li><a href="#configmap-generator-with-git-properties">ConfigMap generator with git properties</a></li>
+            <li><a href="#heredoc-generator">Heredoc generator</a></li>
             <li><a href="#extended-replacement-in-structured-content">Extended replacement in structured content</a></li>
         </ul>
     </li>
@@ -133,7 +134,7 @@ metadata:
         path: krmfnbuiltin
     # Can also be:
     #  container:
-    #    image: ghcr.io/kaweezle/krmfnbuiltin:v0.2.0
+    #    image: ghcr.io/kaweezle/krmfnbuiltin:v0.3.0
 patch: |-
   - op: replace
       path: /spec/source/repoURL
@@ -171,7 +172,7 @@ applications.
 
 ## Use of generators
 
-`krmfnbuiltin` provides all the
+`krmfnbuiltin` provides all the Kustomize
 [builtin generators](https://kubectl.docs.kubernetes.io/references/kustomize/builtins/).
 
 Let's imagine that one or more of your applications use an Helm chart that in
@@ -221,6 +222,8 @@ kind: ConfigMapGenerator
 metadata:
   name: configuration-map
   annotations:
+    # This annotation will be transferred to the generated ConfigMap
+    config.kaweezle.com/local-config: "true"
     config.kubernetes.io/function: |
       exec:
         path: krmfnbuiltin
@@ -240,7 +243,7 @@ metadata:
   name: replacement-transformer
   namespace: argocd
   annotations:
-    # Put this annotation in the last transformation to remove generated resources
+    # Put this annotation in the last transformation to remove the generated resource
     config.kaweezle.com/prune-local: "true"
     config.kubernetes.io/function: |
       exec:
@@ -278,40 +281,57 @@ Some remarks:
   survive reordering.
 - ✔️ The functions file names are prefixed with a number prefix (`01_`, `02_`)
   in order to ensure that the functions are executed in the right order. Note
-  that you can group the two functions in one file separated by `---`.
+  that you can group the two functions in one file separated by `---` (this
+  would make it unusable from [kpt] though).
+- ✔️ The generators contains the annotation:
+
+  ```yaml
+  config.kaweezle.com/local-config: "true"
+  ```
+
+  that is injected in the generated resource.
+
 - ✔️ In the last transformation, we add the following annotation:
 
   ```yaml
   config.kaweezle.com/prune-local: "true"
   ```
 
-  In order to avoid saving the generated resources. This is due to an issue in
-  kustomize that doesn't filter out resources annotated with
-  `config.kubernetes.io/local-config` in the case you are using
-  `kustomize fn run` (although it works with `kustomize build`).
+  In order to avoid saving the generated resources. In the presence of this
+  annotation, `krmfnbuiltin` will remove all the resource having the
+  `config.kaweezle.com/local-config` annotation.
 
 ## Keeping or deleting generated resources
 
-As said above, generated resources are saved by default beside being marked with
-the `config.kubernetes.io/local-config` annotation. To prevent that, adding:
+As said above, generated resources are saved by default. To prevent that,
+adding:
+
+```yaml
+config.kaweezle.com/local-config: "true"
+```
+
+on the generators and:
 
 ```yaml
 config.kaweezle.com/prune-local: "true"
 ```
 
-On the last transformation will remove those resources. If the annotation is not
-present, all the generated resources will be saved in a file named
-`.generated.yaml` located in the configuration directory. You may want to add
+On the last transformation will remove those resources. If the absence of these
+annotations, the generated resources will be saved in a file named
+`.krmfnbuiltin.yaml` located in the configuration directory. You may want to add
 this file name to your `.gitignore` file in order to avoid committing it.
 
 In some cases however, we want to _inject_ new resources in the configuration.
-This can be done by adding the following annotations to the generator:
+This can be done by just omitting the `config.kaweezle.com/local-config`
+annotation.
+
+The name of the file containing the generated resources can be set with the
+following annotations:
 
-- `config.kaweezle.com/keep-local` prevents the deletion of the resource when
-  reaching the transformation annotated with `config.kaweezle.com/prune-local`.
-- `config.kaweezle.com/path` allows specifying the filename of the saved file.
-- `config.kaweezle.com/index` allows specifying the position of the resource in
-  the file.
+- `config.kaweezle.com/path` for the filename. If it contains directories, they
+  will be created.
+- `config.kaweezle.com/index` For the starting index of the resources in the
+  file.
 
 Example:
 
@@ -321,7 +341,7 @@ kind: ConfigMapGenerator
 metadata:
   name: configuration-map
   annotations:
-    config.kaweezle.com/keep-local: "true"
+    # config.kaweezle.com/local-config: "true"
     config.kaweezle.com/path: local-config.yaml
     config.kubernetes.io/function: |
       exec:
@@ -333,6 +353,33 @@ With these annotations, the generated config map will be saved in the
 
 ## Extensions
 
+### Remove Transformer
+
+In the case the transformation(s) involves other transformers than
+`krmfnbuiltin`, the `config.kaweezle.com/prune-local` may not be available to
+remove resources injected in the transformation pipeline. For this use case,
+`krmfnbuiltin` provides `RemoveTransformer`:
+
+```yaml
+apiVersion: builtin
+kind: RemoveTransformer
+metadata:
+  name: replacement-transformer
+  annotations:
+    config.kubernetes.io/function: |
+      exec:
+        path: ../../krmfnbuiltin
+targets:
+  - annotationSelector: config.kaweezle.com/local-config
+```
+
+Each target specified in the `targets` field follows the
+[patches target convention](https://kubectl.docs.kubernetes.io/references/kustomize/builtins/#field-name-patches).
+
+Note that you can use the Kustomize recommended method with a
+`PatchStrategicMergeTransformer` and a `$patch: delete` field. The above
+transformation is however more explicit.
+
 ### ConfigMap generator with git properties
 
 `GitConfigMapGenerator` work identically to `ConfigMapGenerator` except it adds
@@ -533,6 +580,7 @@ metadata:
     # This will inject this resource. like a ConfigMapGenerator, but with hierarchical
     # properties
     config.kaweezle.com/inject-local: "true"
+    config.kaweezle.com/local-config: "true"
     config.kubernetes.io/function: |
       exec:
         path: krmfnbuiltin
@@ -684,6 +732,7 @@ metadata:
   name: configuration-map
   annotations:
     config.kaweezle.com/inject-local: "true"
+    config.kaweezle.com/local-config: "true"
     config.kubernetes.io/function: |
       exec:
         path: ../../krmfnbuiltin
@@ -775,7 +824,7 @@ curl -sLS https://raw.githubusercontent.com/kaweezle/krmfnbuiltin/main/get.sh |
 If you don't want to pipe into shell, you can do:
 
 ```console
-> KRMFNBUILTIN_VERSION="v0.2.0"
+> KRMFNBUILTIN_VERSION="v0.3.0"
 > curl -sLo /usr/local/bin/krmfnbuiltin https://github.com/kaweezle/krmfnbuiltin/releases/download/${KRMFNBUILTIN_VERSION}/krmfnbuiltin_${KRMFNBUILTIN_VERSION}_linux_amd64
 ```
 
@@ -804,7 +853,7 @@ summarize:
 ```Dockerfile
 FROM argoproj/argocd:latest
 
-ARG KRMFNBUILTIN_VERSION=v0.2.0
+ARG KRMFNBUILTIN_VERSION=v0.3.0
 
 # Switch to root for the ability to perform install
 USER root
@@ -842,7 +891,8 @@ this model, a generator or a transformer along its parameters in much like a
 line in a dockerfile. It takes a current configuration as source and generates a
 new configuration after transformation.
 
-While it has not been tested, krmfnbuiltin should work with [kpt].
+krmfnbuiltin works with [kpt]. The `tests/test_krmfnbuiltin_kpt.sh` script
+perform the basic tests with kpt.
 
 [knot8] lenses have provided the idea of extended paths.
 

main.go

@@ -12,7 +12,6 @@ import (
 	"sigs.k8s.io/kustomize/kyaml/errors"
 	"sigs.k8s.io/kustomize/kyaml/fn/framework"
 	"sigs.k8s.io/kustomize/kyaml/fn/framework/command"
-	"sigs.k8s.io/kustomize/kyaml/kio/filters"
 	"sigs.k8s.io/kustomize/kyaml/resid"
 	"sigs.k8s.io/kustomize/kyaml/yaml"
 )
@@ -31,7 +30,7 @@ func main() {
 			if _, ok := config.GetAnnotations()[utils.FunctionAnnotationInjectLocal]; ok {
 				injected := config.Copy()
 
-				err := utils.MakeResourceLocal(injected)
+				err := utils.TransferAnnotations([]*yaml.RNode{injected}, config)
 				if err != nil {
 					return errors.WrapPrefixf(
 						err, "Error while mangling annotations on %s fails configuration", res.OrgId())
@@ -76,19 +75,12 @@ func main() {
 
 			rl.Items = rm.ToRNodeSlice()
 
-			// kustomize fn don't remove config.kubernetes.io/local-config resources upon completion.
-			// As it always add a filename by default, the local resources keep saved.
-			// To avoid this, an annotation `config.kaweezle.com/prune-local` present in a
+			// If the annotation `config.kaweezle.com/prune-local` is present in a
 			// transformer makes all the local resources disappear.
 			if _, ok := config.GetAnnotations()[utils.FunctionAnnotationPruneLocal]; ok {
 				err = rl.Filter(utils.UnLocal)
 				if err != nil {
-					return errors.WrapPrefixf(err, "Removing local from keep-local resources")
-				}
-				filter := &filters.IsLocalConfig{IncludeLocalConfig: false, ExcludeNonLocalConfig: false}
-				err = rl.Filter(filter)
-				if err != nil {
-					return errors.WrapPrefixf(err, "filtering local configs")
+					return errors.WrapPrefixf(err, "while pruning `config.kaweezle.com/local-config` resources")
 				}
 			}
 
@@ -104,17 +96,12 @@ func main() {
 				return errors.WrapPrefixf(err, "generating resource(s)")
 			}
 
-			for _, r := range rm.Resources() {
-				utils.RemoveBuildAnnotations(r)
-				// We add the annotation config.kubernetes.io/local-config to be able to delete
-				// The generated resource at the end of the process. Unfortunately, kustomize doesn't
-				// do that on functions. So we have added a special annotation
-				// `config.kaweezle.com/prune-local` to add on the last transformer.
-				// We set the filename of the generated resource in case it is forgotten.
-				utils.MakeResourceLocal(&r.RNode)
+			rrl := rm.ToRNodeSlice()
+			if err := utils.TransferAnnotations(rrl, config); err != nil {
+				return errors.WrapPrefixf(err, "While transferring annotations")
 			}
 
-			rl.Items = append(rl.Items, rm.ToRNodeSlice()...)
+			rl.Items = append(rl.Items, rrl...)
 
 		}
 
@@ -124,7 +111,7 @@ func main() {
 
 	cmd := command.Build(processor, command.StandaloneDisabled, false)
 	command.AddGenerateDockerfile(cmd)
-	cmd.Version = "v0.2.0" // <---VERSION--->
+	cmd.Version = "v0.3.0" // <---VERSION--->
 
 	if err := cmd.Execute(); err != nil {
 		os.Exit(1)

pkg/extras/RemoveTransformer.go

@@ -0,0 +1,46 @@
+package extras
+
+import (
+	"fmt"
+
+	"sigs.k8s.io/kustomize/api/resmap"
+	"sigs.k8s.io/kustomize/api/types"
+	"sigs.k8s.io/kustomize/kyaml/errors"
+	"sigs.k8s.io/yaml"
+)
+
+type RemoveTransformerPlugin struct {
+	Targets []*types.Selector `json:"targets,omitempty" yaml:"targets,omitempty"`
+}
+
+func (p *RemoveTransformerPlugin) Config(
+	h *resmap.PluginHelpers, c []byte) (err error) {
+	err = yaml.Unmarshal(c, p)
+	if err != nil {
+		return err
+	}
+	return err
+}
+
+func (p *RemoveTransformerPlugin) Transform(m resmap.ResMap) error {
+	if p.Targets == nil {
+		return fmt.Errorf("must specify at least one target")
+	}
+	for _, t := range p.Targets {
+		resources, err := m.Select(*t)
+		if err != nil {
+			return errors.WrapPrefixf(err, "while selecting target %s", t.String())
+		}
+		for _, r := range resources {
+			err = m.Remove(r.CurId())
+			if err != nil {
+				return errors.WrapPrefixf(err, "while removing resource %s", r.CurId().String())
+			}
+		}
+	}
+	return nil
+}
+
+func NewRemoveTransformerPlugin() resmap.TransformerPlugin {
+	return &RemoveTransformerPlugin{}
+}

pkg/plugins/factories.go

@@ -38,6 +38,7 @@ const (
 	HelmChartInflationGenerator
 	ReplacementTransformer
 	GitConfigMapGenerator
+	RemoveTransformer
 )
 
 var stringToBuiltinPluginTypeMap map[string]BuiltinPluginType
@@ -109,6 +110,7 @@ var TransformerFactories = map[BuiltinPluginType]func() resmap.TransformerPlugin
 	ReplacementTransformer:         extras.NewExtendedReplacementTransformerPlugin,
 	ReplicaCountTransformer:        builtins.NewReplicaCountTransformerPlugin,
 	ValueAddTransformer:            builtins.NewValueAddTransformerPlugin,
+	RemoveTransformer:              extras.NewRemoveTransformerPlugin,
 	// Do not wired SortOrderTransformer as a builtin plugin.
 	// We only want it to be available in the top-level kustomization.
 	// See: https://github.com/kubernetes-sigs/kustomize/issues/3913

pkg/utils/constants.go

@@ -23,16 +23,16 @@ const (
 	FunctionAnnotationFunction = ConfigurationAnnotationDomain + "/function"
 
 	// true when the resource is part of the local configuration
-	FunctionAnnotationLocalConfig = ConfigurationAnnotationDomain + "/local-config"
+	FunctionAnnotationLocalConfig = LocalConfigurationAnnotationDomain + "/local-config"
 
 	// Setting to true means we want this function configuration to be injected as a
 	// local configuration resource (local-config)
 	FunctionAnnotationInjectLocal = LocalConfigurationAnnotationDomain + "/inject-local"
 
 	// if set, the transformation will remove all the resources marked as local-config
 	FunctionAnnotationPruneLocal = LocalConfigurationAnnotationDomain + "/prune-local"
-	// if set on a Generated resource, it won't be pruned
-	FunctionAnnotationKeepLocal = LocalConfigurationAnnotationDomain + "/keep-local"
-	FunctionAnnotationPath      = LocalConfigurationAnnotationDomain + "/path"
-	FunctionAnnotationIndex     = LocalConfigurationAnnotationDomain + "/index"
+	// Saving path for injected resource
+	FunctionAnnotationPath = LocalConfigurationAnnotationDomain + "/path"
+	// Saving index for injected resource
+	FunctionAnnotationIndex = LocalConfigurationAnnotationDomain + "/index"
 )