Replace pkger with embed.FS compatibility

kyaml/fn/framework/example/doc.go

@@ -2,11 +2,16 @@
 // SPDX-License-Identifier: Apache-2.0
 
 // Package main contains an example using the the framework.
-// The example annotates all resources in the input with the value provided as a flag.
+// The example annotates all resources in the input with the value provided as a flag,
+// and adds all resources in the templates/ directory to the list.
 //
 // To execute the function, run:
 //
-//   $ cat input/cm.yaml | go run ./main.go --value=foo
+//   $ cat testdata/basic/input.yaml | go run ./main.go --value=foo
+//
+// Alternatively, you can provide the value via a config file instead of a flag:
+//
+//   $ go run ./main.go testdata/basic/config.yaml testdata/basic/input.yaml
 //
 // To generate the Dockerfile for the function image run:
 //

kyaml/fn/framework/example/main.go

@@ -4,29 +4,49 @@
 package main
 
 import (
+	"embed"
 	"fmt"
 	"os"
 
+	"github.com/spf13/cobra"
 	"sigs.k8s.io/kustomize/kyaml/fn/framework"
 	"sigs.k8s.io/kustomize/kyaml/fn/framework/command"
-	"sigs.k8s.io/kustomize/kyaml/yaml"
+	"sigs.k8s.io/kustomize/kyaml/fn/framework/parser"
 )
 
-func main() {
-	var value string
-	fn := func(rl *framework.ResourceList) error {
-		for i := range rl.Items {
-			// set the annotation on each resource item
-			if err := rl.Items[i].PipeE(yaml.SetAnnotation("value", value)); err != nil {
-				return err
-			}
-		}
-		return nil
-	}
-	cmd := command.Build(framework.ResourceListProcessorFunc(fn), command.StandaloneEnabled, false)
-	cmd.Flags().StringVar(&value, "value", "", "annotation value")
+//go:embed templates/*
+var templateFS embed.FS
 
-	if err := cmd.Execute(); err != nil {
+var annotationTemplate = `
+metadata:
+  annotations: 
+    value: {{ .Value }}
+`
+
+func buildProcessor(value *string) framework.ResourceListProcessor {
+	return framework.TemplateProcessor{
+		ResourceTemplates: []framework.ResourceTemplate{{
+			Templates: parser.TemplateFiles("templates").FromFS(templateFS),
+		}},
+		PatchTemplates: []framework.PatchTemplate{&framework.ResourcePatchTemplate{
+			Templates: parser.TemplateStrings(annotationTemplate),
+		}},
+		// This will be populated from the --value flag if provided,
+		// or the config file's `value` field if provided, with the latter taking precedence.
+		TemplateData: struct {
+			Value *string `yaml:"value"`
+		}{Value: value}}
+}
+
+func buildCmd() *cobra.Command {
+	var value string
+	cmd := command.Build(buildProcessor(&value), command.StandaloneEnabled, false)
+	cmd.Flags().StringVar(&value, "value", "", "annotation value")
+	return cmd
+}
+
+func main() {
+	if err := buildCmd().Execute(); err != nil {
 		fmt.Println(err)
 		os.Exit(1)
 	}

kyaml/fn/framework/example/main_test.go

@@ -0,0 +1,17 @@
+// Copyright 2021 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+package main
+
+import (
+	"testing"
+
+	"sigs.k8s.io/kustomize/kyaml/fn/framework/frameworktestutil"
+)
+
+func TestRun(t *testing.T) {
+	prc := frameworktestutil.CommandResultsChecker{
+		Command: buildCmd,
+	}
+	prc.Assert(t)
+}

kyaml/fn/framework/example/templates/service_account.template.yaml

@@ -0,0 +1,7 @@
+# Copyright 2021 The Kubernetes Authors.
+# SPDX-License-Identifier: Apache-2.0
+
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: {{ .Value }}

kyaml/fn/framework/example/testdata/basic/config.yaml

@@ -0,0 +1,6 @@
+# Copyright 2019 The Kubernetes Authors.
+# SPDX-License-Identifier: Apache-2.0
+
+apiVersion: example.com/v1alpha1
+kind: Tester
+value: foo

kyaml/fn/framework/example/testdata/basic/expected.yaml

@@ -0,0 +1,21 @@
+# Copyright 2021 The Kubernetes Authors.
+# SPDX-License-Identifier: Apache-2.0
+
+kind: ConfigMap
+apiVersion: v1
+metadata:
+  name: tester
+  annotations:
+    value: foo
+data:
+  some: data
+---
+# Copyright 2021 The Kubernetes Authors.
+# SPDX-License-Identifier: Apache-2.0
+
+apiVersion: v1
+kind: ServiceAccount
+metadata:
+  name: foo
+  annotations:
+    value: foo