Add support for using arbitrary Go template when generating markdown.

.golangci.yml

@@ -133,3 +133,5 @@ linters-settings:
       - typeUnparen
       - unnamedResult
       - unnecessaryBlock
+  gocyclo:
+    min-complexity: 31

cmd/release-notes/README.md

@@ -87,7 +87,7 @@ level=debug timestamp=2019-07-30T04:02:44.3716249Z caller=notes.go:497 msg="Excl
 | release-tars            | RELEASE_TARS    |                    | No       | Directory of tars to sha512 sum for display                                                                                       |
 | **OUTPUT OPTIONS**      |
 | output                  | OUTPUT          |                    | No       | The path where the release notes will be written                                                                                  |
-| format                  | FORMAT          | markdown           | Yes      | The format for notes output (options: markdown, json)                                                                             |
+| format                  | FORMAT          | markdown           | Yes      | The format for notes output (options: markdown, json, go-template:path/to/template.file)                                                                             |
 | release-version         | RELEASE_VERSION |                    | No       | The release version to tag the notes with                                                                                         |
 | **LOG OPTIONS**         |
 | debug                   | DEBUG           | false              | No       | Enable debug logging (options: true, false)                                                                                       |
@@ -125,6 +125,10 @@ cp ./bazel-bin/cmd/release-notes/darwin_amd64_stripped/release-notes /usr/local/
 
 Check out the rendering of 1.11's release notes [here](https://gist.github.com/marpaia/acfdb889f362195bb683e9e09ce196bc).
 
-### Why formats are supported?
+### What formats are supported?
+
+Right now the tool can output release notes in Markdown and JSON. The tool
+also supports arbitrary formats using go-templates. The template has access
+to fields in the `Document` struct. For an example, see the default markdown
+template (`pkg/notes/internal/template.go`) used to render the stock format.
 
-Right now the tool can output release notes in Markdown and JSON.

cmd/release-notes/main.go

@@ -141,8 +141,10 @@ func init() {
 	cmd.PersistentFlags().StringVar(
 		&opts.Format,
 		"format",
-		util.EnvDefault("FORMAT", "markdown"),
-		"The format for notes output (options: markdown, json)",
+		util.EnvDefault("FORMAT", "go-template:default"),
+		fmt.Sprintf("The format for notes output (options: %s)",
+			strings.Join([]string{"markdown", "json", "go-template:default"}, ", "),
+		),
 	)
 
 	cmd.PersistentFlags().StringVar(
@@ -241,8 +243,8 @@ func WriteReleaseNotes(releaseNotes notes.ReleaseNotes, history notes.ReleaseNot
 	}
 
 	// Contextualized release notes can be printed in a variety of formats
-	switch opts.Format {
-	case "json":
+	switch format := opts.Format; {
+	case format == "json":
 		byteValue, err := ioutil.ReadAll(output)
 		if err != nil {
 			return err
@@ -275,15 +277,20 @@ func WriteReleaseNotes(releaseNotes notes.ReleaseNotes, history notes.ReleaseNot
 		if err := enc.Encode(releaseNotes); err != nil {
 			return errors.Wrapf(err, "encoding JSON output")
 		}
-	case "markdown":
+	case strings.Contains(format, "go-template"):
+		goTemplate := strings.Split(format, ":")[1]
+
 		doc, err := document.CreateDocument(releaseNotes, history)
 		if err != nil {
 			return errors.Wrapf(err, "creating release note document")
 		}
 
-		markdown, err := doc.RenderMarkdown(
-			opts.ReleaseBucket, opts.ReleaseTars, opts.StartRev, opts.EndRev,
-		)
+		// TODO: Not sure these options are guaranteed to be set but we need
+		// them in rendering. Perhaps these should be set in CreateDocument()?
+		doc.PreviousRevision = opts.StartRev
+		doc.CurrentRevision = opts.EndRev
+
+		markdown, err := doc.RenderMarkdownTemplate(opts.ReleaseBucket, opts.ReleaseTars, goTemplate)
 		if err != nil {
 			return errors.Wrapf(err, "rendering release note document to markdown")
 		}

go.mod

@@ -5,10 +5,12 @@ go 1.13
 require (
 	cloud.google.com/go v0.44.3
 	github.com/GoogleCloudPlatform/testgrid v0.0.1-alpha.4
+	github.com/bazelbuild/rules_go v0.22.1
 	github.com/blang/semver v3.5.1+incompatible
 	github.com/golangci/golangci-lint v1.23.3
 	github.com/google/go-github/v29 v29.0.3
 	github.com/google/uuid v1.1.1
+	github.com/kr/pretty v0.1.0
 	github.com/maxbrunsfeld/counterfeiter/v6 v6.2.2
 	github.com/nozzle/throttler v0.0.0-20180817012639-2ea982251481
 	github.com/pkg/errors v0.9.1

go.sum

@@ -26,6 +26,8 @@ github.com/anmitsu/go-shlex v0.0.0-20161002113705-648efa622239/go.mod h1:2FmKhYU
 github.com/armon/consul-api v0.0.0-20180202201655-eb2c6b5be1b6/go.mod h1:grANhF5doyWs3UAsr3K4I6qtAmlQcZDesFNEHPZAzj8=
 github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5 h1:0CwZNZbxp69SHPdPJAN/hZIm0C4OItdklCFmMRWYpio=
 github.com/armon/go-socks5 v0.0.0-20160902184237-e75332964ef5/go.mod h1:wHh0iHkYZB8zMSxRWpUBQtwG5a7fFgvEO+odwuTv2gs=
+github.com/bazelbuild/rules_go v0.22.1 h1:GRtyhztX3PNl4lhPhhn+eORpNfrFvygcVCQKgMv8lG8=
+github.com/bazelbuild/rules_go v0.22.1/go.mod h1:MC23Dc/wkXEyk3Wpq6lCqz0ZAYOZDw2DR5y3N1q2i7M=
 github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24TaqPxmxbtue+5NUziq4I4S80YR8gNf3Q=
 github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+CedLV8=
 github.com/blang/semver v3.5.1+incompatible h1:cQNTCjp13qL8KC3Nbxr/y2Bqb63oX6wdnnjpJbkM4JQ=
@@ -188,6 +190,7 @@ github.com/inconshreveable/mousetrap v1.0.0 h1:Z8tu5sraLXCXIcARxBp/8cbvlwVa7Z1NH
 github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
 github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 h1:BQSFePA1RWJOlocH6Fxy8MmwDt+yVQYULKfN0RoTN8A=
 github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99/go.mod h1:1lJo3i6rXxKeerYnT8Nvf0QmHCRC1n8sfWVwXF2Frvo=
+github.com/jessevdk/go-flags v1.4.0 h1:4IU2WS7AumrZ/40jfhf4QVDMsQwqA7VEHozFRrGARJA=
 github.com/jessevdk/go-flags v1.4.0/go.mod h1:4FA24M0QyGHXBuZZK/XkWh8h0e1EYbRYJSGM75WSRxI=
 github.com/jingyugao/rowserrcheck v0.0.0-20191204022205-72ab7603b68a h1:GmsqmapfzSJkm28dhRoHz2tLRbJmqhU86IPgBtN3mmk=
 github.com/jingyugao/rowserrcheck v0.0.0-20191204022205-72ab7603b68a/go.mod h1:xRskid8CManxVta/ALEhJha/pweKBaVG6fWgc0yH25s=

pkg/notes/document/BUILD.bazel

@@ -14,8 +14,14 @@ go_library(
 go_test(
     name = "go_default_test",
     srcs = ["document_test.go"],
+    data = ["testdata/document.md.golden"],
     embed = [":go_default_library"],
-    deps = ["@com_github_stretchr_testify//require:go_default_library"],
+    deps = [
+        "//pkg/notes/internal:go_default_library",
+        "@com_github_kr_pretty//:go_default_library",
+        "@com_github_stretchr_testify//require:go_default_library",
+        "@io_bazel_rules_go//go/tools/bazel:go_default_library",
+    ],
 )
 
 filegroup(

pkg/notes/document/document.go

@@ -24,16 +24,101 @@ import (
 	"path/filepath"
 	"sort"
 	"strings"
+	"text/template"
 
 	"github.com/pkg/errors"
 	"k8s.io/release/pkg/notes"
 )
 
 // Document represents the underlying structure of a release notes document.
 type Document struct {
-	NotesWithActionRequired Notes       `json:"action_required"`
-	NotesUncategorized      Notes       `json:"uncategorized"`
-	NotesByKind             NotesByKind `json:"kinds"`
+	NotesWithActionRequired Notes         `json:"action_required"`
+	NotesUncategorized      Notes         `json:"uncategorized"`
+	NotesByKind             NotesByKind   `json:"kinds"`
+	Downloads               *FileMetadata `json:"downloads"`
+	CurrentRevision         string        `json:"release_tag"`
+	PreviousRevision        string
+}
+
+// FileMetadata contains metadata about files associated with the release.
+type FileMetadata struct {
+	// Files containing source code.
+	Source []File
+
+	// Client binaries.
+	Client []File
+
+	// Server binaries.
+	Server []File
+
+	// TODO: What is this?
+	Node []File
+}
+
+// FetchMetadata generates file metadata from files in `dir`
+func (f *FileMetadata) FetchMetadata(dir, urlPrefix, tag string) (*FileMetadata, error) {
+	if dir == "" {
+		return nil, nil
+	}
+	if tag == "" {
+		return nil, errors.New("release tags not specified")
+	}
+	if urlPrefix == "" {
+		return nil, errors.New("url prefix not specified")
+	}
+
+	fm := new(FileMetadata)
+	m := map[*[]File][]string{
+		&fm.Source: {"kubernetes.tar.gz", "kubernetes-src.tar.gz"},
+		&fm.Client: {"kubernetes-client*.tar.gz"},
+		&fm.Server: {"kubernetes-server*.tar.gz"},
+		&fm.Node:   {"kubernetes-node*.tar.gz"},
+	}
+	for fileType, patterns := range m {
+		fileMetadata, err := f.newFile(dir, patterns, urlPrefix, tag)
+		if err != nil {
+			return nil, errors.Wrap(err, "fetching file metadata")
+		}
+		*fileType = append(*fileType, fileMetadata...)
+	}
+
+	return fm, nil
+}
+
+func (f *FileMetadata) newFile(dir string, patterns []string, urlPrefix, tag string) ([]File, error) {
+	var files []File
+	for _, pattern := range patterns {
+		matches, err := filepath.Glob(filepath.Join(dir, pattern))
+		if err != nil {
+			return nil, err
+		}
+
+		for _, filePath := range matches {
+			f, err := os.Open(filePath)
+			if err != nil {
+				return nil, err
+			}
+			defer f.Close()
+
+			h := sha512.New()
+			if _, err := io.Copy(h, f); err != nil {
+				return nil, err
+			}
+
+			fileName := filepath.Base(filePath)
+			files = append(files, File{
+				Checksum: fmt.Sprintf("%x", h.Sum(nil)),
+				Name:     fileName,
+				URL:      fmt.Sprintf("%s/%s/%s", urlPrefix, tag, fileName),
+			})
+		}
+	}
+	return files, nil
+}
+
+// A File is a downloadable file.
+type File struct {
+	Checksum, Name, URL string
 }
 
 type Kind string
@@ -117,6 +202,34 @@ func CreateDocument(releaseNotes notes.ReleaseNotes, history notes.ReleaseNotesH
 	return doc, nil
 }
 
+// RenderMarkdownTemplate renders a document using the Go template in `goTemplate`.
+func (d *Document) RenderMarkdownTemplate(bucket, fileDir, goTemplate string) (string, error) {
+	urlPrefix := fmt.Sprintf("https://storage.googleapis.com/%s/release", bucket)
+	if bucket == "kubernetes-release" {
+		urlPrefix = "https://dl.k8s.io"
+	}
+
+	fm := new(FileMetadata)
+	fileMetadata, err := fm.FetchMetadata(fileDir, urlPrefix, d.CurrentRevision)
+	if err != nil {
+		return "", errors.Wrap(err, "fetching downloads metadata")
+	}
+	d.Downloads = fileMetadata
+
+	tmpl, err := template.New("markdown").
+		Funcs(template.FuncMap{"prettyKind": prettyKind}).
+		Parse(goTemplate)
+	if err != nil {
+		return "", errors.Wrap(err, "parsing template")
+	}
+
+	var s strings.Builder
+	if err := tmpl.Execute(&s, d); err != nil {
+		return "", errors.Wrapf(err, "rendering with template")
+	}
+	return s.String(), nil
+}
+
 // RenderMarkdown accepts a Document and writes a version of that document to
 // supplied io.Writer in markdown format.
 func (d *Document) RenderMarkdown(bucket, tars, prevTag, newTag string) (string, error) {