feat: generate Dockerfile from declarative plugin

We need to copy the channels directory in the Dockerfile, particularly
now that we're running with non-root permissions and it is no longer a
one-liner.

Signed-off-by: Vivek Singh <svivekkumar@vmware.com>

pkg/plugins/golang/declarative/v1/api.go

@@ -19,25 +19,20 @@ package v1
 import (
 	"errors"
 	"fmt"
-	"path/filepath"
-
-	"github.com/spf13/afero"
 
 	"sigs.k8s.io/kubebuilder/v3/pkg/config"
 	"sigs.k8s.io/kubebuilder/v3/pkg/machinery"
 	"sigs.k8s.io/kubebuilder/v3/pkg/model/resource"
 	"sigs.k8s.io/kubebuilder/v3/pkg/plugin"
 	"sigs.k8s.io/kubebuilder/v3/pkg/plugin/util"
-	"sigs.k8s.io/kubebuilder/v3/pkg/plugins/golang/declarative/v1/internal/templates"
+	"sigs.k8s.io/kubebuilder/v3/pkg/plugins/golang/declarative/v1/scaffolds"
 	goPluginV2 "sigs.k8s.io/kubebuilder/v3/pkg/plugins/golang/v2"
 )
 
 const (
 	// kbDeclarativePattern is the sigs.k8s.io/kubebuilder-declarative-pattern version
 	kbDeclarativePatternForV2 = "v0.0.0-20200522144838-848d48e5b073"
 	kbDeclarativePatternForV3 = "fea7e5cc701290589ec20ef4d9c0629d08b5307d"
-
-	exampleManifestVersion = "0.0.1"
 )
 
 var _ plugin.CreateAPISubcommand = &createAPISubcommand{}
@@ -97,27 +92,11 @@ func (p *createAPISubcommand) InjectResource(res *resource.Resource) error {
 func (p *createAPISubcommand) Scaffold(fs machinery.Filesystem) error {
 	fmt.Println("updating scaffold with declarative pattern...")
 
-	// Load the boilerplate
-	bp, err := afero.ReadFile(fs.FS, filepath.Join("hack", "boilerplate.go.txt"))
+	scaffolder := scaffolds.NewAPIScaffolder(p.config, *p.resource)
+	scaffolder.InjectFS(fs)
+	err := scaffolder.Scaffold()
 	if err != nil {
-		return fmt.Errorf("error updating scaffold: unable to load boilerplate: %w", err)
-	}
-	boilerplate := string(bp)
-
-	// Initialize the machinery.Scaffold that will write the files to disk
-	scaffold := machinery.NewScaffold(fs,
-		machinery.WithConfig(p.config),
-		machinery.WithBoilerplate(boilerplate),
-		machinery.WithResource(p.resource),
-	)
-
-	if err := scaffold.Execute(
-		&templates.Types{},
-		&templates.Controller{},
-		&templates.Channel{ManifestVersion: exampleManifestVersion},
-		&templates.Manifest{ManifestVersion: exampleManifestVersion},
-	); err != nil {
-		return fmt.Errorf("error updating scaffold: %w", err)
+		return err
 	}
 
 	// Track the resources following a declarative approach

pkg/plugins/golang/declarative/v1/init.go

@@ -0,0 +1,46 @@
+/*
+Copyright 2021 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package v1
+
+import (
+	"sigs.k8s.io/kubebuilder/v3/pkg/config"
+	"sigs.k8s.io/kubebuilder/v3/pkg/machinery"
+	"sigs.k8s.io/kubebuilder/v3/pkg/plugin"
+	"sigs.k8s.io/kubebuilder/v3/pkg/plugins/golang/declarative/v1/scaffolds"
+)
+
+var _ plugin.InitSubcommand = &initSubcommand{}
+
+type initSubcommand struct {
+	config config.Config
+}
+
+func (p *initSubcommand) InjectConfig(c config.Config) error {
+	p.config = c
+
+	return nil
+}
+
+func (p *initSubcommand) Scaffold(fs machinery.Filesystem) error {
+	scaffolder := scaffolds.NewInitScaffolder(p.config)
+	scaffolder.InjectFS(fs)
+	err := scaffolder.Scaffold()
+	if err != nil {
+		return err
+	}
+	return nil
+}

pkg/plugins/golang/declarative/v1/internal/templates/dockerfile.go

@@ -0,0 +1,76 @@
+/*
+Copyright 2021 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package templates
+
+import (
+	"sigs.k8s.io/kubebuilder/v3/pkg/machinery"
+)
+
+var _ machinery.Template = &Dockerfile{}
+
+// Dockerfile scaffolds a file that defines the containerized build process
+type Dockerfile struct {
+	machinery.TemplateMixin
+}
+
+// SetTemplateDefaults implements file.Template
+func (f *Dockerfile) SetTemplateDefaults() error {
+	if f.Path == "" {
+		f.Path = "Dockerfile"
+	}
+
+	f.TemplateBody = dockerfileTemplate
+
+	f.IfExistsAction = machinery.OverwriteFile
+
+	return nil
+}
+
+const dockerfileTemplate = `# Build the manager binary
+FROM golang:1.16 as builder
+
+WORKDIR /workspace
+# Copy the Go Modules manifests
+COPY go.mod go.mod
+COPY go.sum go.sum
+# cache deps before building and copying source so that we don't need to re-download as much
+# and so that source changes don't invalidate our downloaded layer
+RUN go mod download
+
+# Copy the go source
+COPY main.go main.go
+COPY api/ api/
+COPY controllers/ controllers/
+
+# Build
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -a -o manager main.go
+
+# Stage channels and make readable
+COPY channels/ /channels/
+RUN chmod -R a+rx /channels/
+
+# Use distroless as minimal base image to package the manager binary
+# Refer to https://github.com/GoogleContainerTools/distroless for more details
+FROM gcr.io/distroless/static:nonroot
+WORKDIR /
+COPY --from=builder /workspace/manager .
+COPY --from=builder /channels /channels
+
+USER 65532:65532
+
+ENTRYPOINT ["/manager"]
+`

pkg/plugins/golang/declarative/v1/plugin.go

@@ -37,6 +37,7 @@ var _ plugin.CreateAPI = Plugin{}
 
 // Plugin implements the plugin.Full interface
 type Plugin struct {
+	initSubcommand
 	createAPISubcommand
 }
 
@@ -49,6 +50,9 @@ func (Plugin) Version() plugin.Version { return pluginVersion }
 // SupportedProjectVersions returns an array with all project versions supported by the plugin
 func (Plugin) SupportedProjectVersions() []config.Version { return supportedProjectVersions }
 
+// GetInitSubcommand will return the subcommand which is responsible for initializing and common scaffolding
+func (p Plugin) GetInitSubcommand() plugin.InitSubcommand { return &p.initSubcommand }
+
 // GetCreateAPISubcommand will return the subcommand which is responsible for scaffolding apis
 func (p Plugin) GetCreateAPISubcommand() plugin.CreateAPISubcommand { return &p.createAPISubcommand }
 

pkg/plugins/golang/declarative/v1/scaffolds/api.go

@@ -0,0 +1,84 @@
+/*
+Copyright 2022 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package scaffolds
+
+import (
+	"fmt"
+	"path/filepath"
+
+	"github.com/spf13/afero"
+	"sigs.k8s.io/kubebuilder/v3/pkg/config"
+	"sigs.k8s.io/kubebuilder/v3/pkg/machinery"
+	"sigs.k8s.io/kubebuilder/v3/pkg/model/resource"
+	"sigs.k8s.io/kubebuilder/v3/pkg/plugins"
+	"sigs.k8s.io/kubebuilder/v3/pkg/plugins/golang/declarative/v1/internal/templates"
+)
+
+const (
+	exampleManifestVersion = "0.0.1"
+)
+
+var _ plugins.Scaffolder = &apiScaffolder{}
+
+type apiScaffolder struct {
+	config   config.Config
+	resource resource.Resource
+
+	// fs is the filesystem that will be used by the scaffolder
+	fs machinery.Filesystem
+}
+
+// NewAPIScaffolder returns a new Scaffolder for declarative
+func NewAPIScaffolder(config config.Config, res resource.Resource) plugins.Scaffolder {
+	return &apiScaffolder{
+		config:   config,
+		resource: res,
+	}
+}
+
+// InjectFS implements cmdutil.Scaffolder
+func (s *apiScaffolder) InjectFS(fs machinery.Filesystem) {
+	s.fs = fs
+}
+
+// Scaffold implements cmdutil.Scaffolder
+func (s *apiScaffolder) Scaffold() error {
+	// Load the boilerplate
+	boilerplate, err := afero.ReadFile(s.fs.FS, filepath.Join("hack", "boilerplate.go.txt"))
+	if err != nil {
+		return fmt.Errorf("error updating scaffold: unable to load boilerplate: %w", err)
+	}
+
+	// Initialize the machinery.Scaffold that will write the files to disk
+	scaffold := machinery.NewScaffold(s.fs,
+		machinery.WithConfig(s.config),
+		machinery.WithBoilerplate(string(boilerplate)),
+		machinery.WithResource(&s.resource),
+	)
+
+	err = scaffold.Execute(
+		&templates.Types{},
+		&templates.Controller{},
+		&templates.Channel{ManifestVersion: exampleManifestVersion},
+		&templates.Manifest{ManifestVersion: exampleManifestVersion},
+		&templates.Dockerfile{},
+	)
+	if err != nil {
+		return fmt.Errorf("error updating scaffold: %w", err)
+	}
+	return nil
+}

pkg/plugins/golang/declarative/v1/scaffolds/init.go

@@ -0,0 +1,64 @@
+/*
+Copyright 2022 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package scaffolds
+
+import (
+	"fmt"
+
+	"sigs.k8s.io/kubebuilder/v3/pkg/config"
+	"sigs.k8s.io/kubebuilder/v3/pkg/machinery"
+	"sigs.k8s.io/kubebuilder/v3/pkg/plugins"
+	"sigs.k8s.io/kubebuilder/v3/pkg/plugins/golang/declarative/v1/internal/templates"
+)
+
+var _ plugins.Scaffolder = &initScaffolder{}
+
+type initScaffolder struct {
+	config config.Config
+
+	// fs is the filesystem that will be used by the scaffolder
+	fs machinery.Filesystem
+}
+
+// NewInitScaffolder returns a new Scaffolder for declarative
+func NewInitScaffolder(config config.Config) plugins.Scaffolder {
+	return &apiScaffolder{
+		config: config,
+	}
+}
+
+// InjectFS implements cmdutil.Scaffolder
+func (s *initScaffolder) InjectFS(fs machinery.Filesystem) {
+	s.fs = fs
+}
+
+// Scaffold implements cmdutil.Scaffolder
+func (s *initScaffolder) Scaffold() error {
+
+	// Initialize the machinery.Scaffold that will write the files to disk
+	scaffold := machinery.NewScaffold(s.fs,
+		machinery.WithConfig(s.config),
+	)
+
+	err := scaffold.Execute(
+		&templates.Dockerfile{},
+	)
+	if err != nil {
+		return fmt.Errorf("error updating scaffold: %w", err)
+	}
+	return nil
+}

testdata/project-v2-addon/Dockerfile

@@ -1,5 +1,5 @@
 # Build the manager binary
-FROM golang:1.13 as builder
+FROM golang:1.16 as builder
 
 WORKDIR /workspace
 # Copy the Go Modules manifests
@@ -15,13 +15,19 @@ COPY api/ api/
 COPY controllers/ controllers/
 
 # Build
-RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 GO111MODULE=on go build -a -o manager main.go
+RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -a -o manager main.go
+
+# Stage channels and make readable
+COPY channels/ /channels/
+RUN chmod -R a+rx /channels/
 
 # Use distroless as minimal base image to package the manager binary
 # Refer to https://github.com/GoogleContainerTools/distroless for more details
 FROM gcr.io/distroless/static:nonroot
 WORKDIR /
 COPY --from=builder /workspace/manager .
-USER nonroot:nonroot
+COPY --from=builder /channels /channels
+
+USER 65532:65532
 
 ENTRYPOINT ["/manager"]

testdata/project-v3-addon/Dockerfile

@@ -17,11 +17,17 @@ COPY controllers/ controllers/
 # Build
 RUN CGO_ENABLED=0 GOOS=linux GOARCH=amd64 go build -a -o manager main.go
 
+# Stage channels and make readable
+COPY channels/ /channels/
+RUN chmod -R a+rx /channels/
+
 # Use distroless as minimal base image to package the manager binary
 # Refer to https://github.com/GoogleContainerTools/distroless for more details
 FROM gcr.io/distroless/static:nonroot
 WORKDIR /
 COPY --from=builder /workspace/manager .
+COPY --from=builder /channels /channels
+
 USER 65532:65532
 
 ENTRYPOINT ["/manager"]