Extend plugin interface with execute method

Change introduces evolution of airshipctl document plugins which
are compatible to the new approach for kustomize plugins.

Change-Id: I422110ba523b97c8a80a0b82cb43b70a4ee8e558
Relates-To: #322

docs/source/cli/airshipctl_image_build.md

@@ -13,7 +13,8 @@ airshipctl image build [flags]
 ### Options
 
 ```
-  -h, --help   help for build
+  -h, --help       help for build
+      --progress   show progress
 ```
 
 ### Options inherited from parent commands

go.mod

@@ -34,6 +34,7 @@ require (
 	sigs.k8s.io/cluster-api v0.3.5
 	sigs.k8s.io/controller-runtime v0.5.2
 	sigs.k8s.io/kustomize/api v0.5.1
+	sigs.k8s.io/kustomize/kyaml v0.6.0
 	sigs.k8s.io/yaml v1.2.0
 )
 

pkg/document/plugin/replacement/transformer.go

@@ -16,9 +16,11 @@ import (
 	"sigs.k8s.io/kustomize/api/resmap"
 	"sigs.k8s.io/kustomize/api/resource"
 	"sigs.k8s.io/kustomize/api/types"
+	"sigs.k8s.io/kustomize/kyaml/yaml"
 
 	airshipv1 "opendev.org/airship/airshipctl/pkg/api/v1alpha1"
 	plugtypes "opendev.org/airship/airshipctl/pkg/document/plugin/types"
+	"opendev.org/airship/airshipctl/pkg/errors"
 )
 
 var (
@@ -31,6 +33,8 @@ const (
 	dotReplacer = "$$$$"
 )
 
+var _ plugtypes.Plugin = &plugin{}
+
 type plugin struct {
 	*airshipv1.ReplacementTransformer
 }
@@ -110,6 +114,10 @@ func (p *plugin) Transform(m resmap.ResMap) error {
 	return nil
 }
 
+func (p *plugin) Filter(items []*yaml.RNode) ([]*yaml.RNode, error) {
+	return nil, errors.ErrNotImplemented{What: "`Exec` method for replacement transformer"}
+}
+
 func getReplacement(m resmap.ResMap, objRef *types.Target, fieldRef string) (interface{}, error) {
 	s := types.Selector{
 		Gvk:       objRef.Gvk,

pkg/document/plugin/templater/templater.go

@@ -15,18 +15,23 @@
 package templater
 
 import (
+	"bytes"
+	"fmt"
 	"io"
 	"text/template"
 
 	"github.com/Masterminds/sprig"
 
 	"k8s.io/apimachinery/pkg/runtime"
-	"sigs.k8s.io/yaml"
+	"sigs.k8s.io/kustomize/kyaml/kio"
+	"sigs.k8s.io/kustomize/kyaml/yaml"
 
 	airshipv1 "opendev.org/airship/airshipctl/pkg/api/v1alpha1"
 	plugtypes "opendev.org/airship/airshipctl/pkg/document/plugin/types"
 )
 
+var _ plugtypes.Plugin = &plugin{}
+
 type plugin struct {
 	*airshipv1.Templater
 }
@@ -54,6 +59,29 @@ func (t *plugin) Run(_ io.Reader, out io.Writer) error {
 	return tmpl.Execute(out, t.Values)
 }
 
+func (t *plugin) Filter(items []*yaml.RNode) ([]*yaml.RNode, error) {
+	out := &bytes.Buffer{}
+	err := t.Run(nil, out)
+	if err != nil {
+		return nil, err
+	}
+
+	p := kio.Pipeline{
+		Inputs:  []kio.Reader{&kio.ByteReader{Reader: out}},
+		Outputs: []kio.Writer{&kio.PackageBuffer{}},
+	}
+	err = p.Execute()
+	if err != nil {
+		return nil, err
+	}
+
+	res, ok := p.Outputs[0].(*kio.PackageBuffer)
+	if !ok {
+		return nil, fmt.Errorf("Output conversion error")
+	}
+	return append(items, res.Nodes...), nil
+}
+
 // Render input yaml as output yaml
 // This function is from the Helm project:
 // https://github.com/helm/helm

pkg/document/plugin/templater/templater_test.go

@@ -20,6 +20,8 @@ import (
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+
+	"sigs.k8s.io/kustomize/kyaml/kio"
 	"sigs.k8s.io/yaml"
 
 	"opendev.org/airship/airshipctl/pkg/document/plugin/templater"
@@ -53,8 +55,7 @@ template: |
   spec:
     bootMACAddress: {{ .macAddress }}
   {{ end -}}`,
-			expectedOut: `---
+			expectedOut: `apiVersion: metal3.io/v1alpha1
-apiVersion: metal3.io/v1alpha1
 kind: BareMetalHost
 metadata:
   name: node-1
@@ -77,6 +78,8 @@ metadata:
   name: notImportantHere
 values:
   test:
+    someKey:
+      anotherKey: value
     of:
       - toYaml
 template: |
@@ -85,6 +88,8 @@ template: |
 			expectedOut: `test:
   of:
   - toYaml
+  someKey:
+    anotherKey: value
 `,
 		},
 		{
@@ -121,10 +126,12 @@ template: |
 		plugin, err := templater.New(cfg)
 		require.NoError(t, err)
 		buf := &bytes.Buffer{}
-		err = plugin.Run(nil, buf)
+		nodes, err := plugin.Filter(nil)
 		if tc.expectedErr != "" {
 			assert.EqualError(t, err, tc.expectedErr)
 		}
+		err = kio.ByteWriter{Writer: buf}.Write(nodes)
+		require.NoError(t, err)
 		assert.Equal(t, tc.expectedOut, buf.String())
 	}
 }

pkg/document/plugin/types/plugin.go

@@ -16,10 +16,13 @@ package types
 
 import (
 	"io"
+
+	"sigs.k8s.io/kustomize/kyaml/kio"
 )
 
 // Plugin interface for airship document plugins
 type Plugin interface {
+	kio.Filter
 	Run(io.Reader, io.Writer) error
 }