Add release-notes check subcommand

This commit adds a new "check" subcommand to the release-notes
utility.  This subcommand reads a PR from the github API and
check if it has a valid release note. If not it exits non-zero.

It is designed to easily add a PR check in CI to enforce authors
to add release notes.

Signed-off-by: Adolfo García Veytia (Puerco) <adolfo.garcia@uservers.net>

cmd/release-notes/check.go

@@ -0,0 +1,189 @@
+/*
+Copyright 2023 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 main
+
+import (
+	"context"
+	"errors"
+	"fmt"
+	"os"
+
+	"github.com/spf13/cobra"
+	"k8s.io/release/pkg/notes"
+	"k8s.io/release/pkg/notes/options"
+	"sigs.k8s.io/release-utils/env"
+)
+
+const (
+	pullRequestGuidance = "The pull request(s) specified do not have a valid release note.\n\n" +
+		"Make sure the PRs have a ```release-note block (see help) in the PR body with markdown text\n" +
+		"clearly specifying the change being introduced in your commits.\n\n" +
+		"If you want to skip the release notes check, you can type NONE in the release notes block\n" +
+		"or add a \"release-notes-none\" (without quotes) to your PR. This will\n" +
+		"tell the release notes checker to allow PRs without a note.\n\n" +
+		"For more information see:\n" +
+		"https://github.com/kubernetes/release/tree/master/cmd/release-notes\n\n\n"
+	bkTicks = "```"
+)
+
+type checkPROptions struct {
+	options.Options
+	PullRequests []int
+}
+
+func (o *checkPROptions) ValidateAndFinish() error {
+	var lenErr, prNrErr, orgErr, repoErr error
+	if len(o.PullRequests) == 0 {
+		lenErr = fmt.Errorf("no pull requests numbers specified")
+	}
+
+	for _, n := range o.PullRequests {
+		if n == 0 {
+			prNrErr = fmt.Errorf("invalid pull request number (must be an integer larger than 0)")
+			break
+		}
+	}
+
+	if o.GithubOrg == "" {
+		orgErr = fmt.Errorf("no GitHub organization specified")
+	}
+
+	if o.GithubRepo == "" {
+		orgErr = fmt.Errorf("no GitHub repository specified")
+	}
+
+	return errors.Join(
+		lenErr, prNrErr, orgErr, repoErr,
+	)
+}
+
+var checkPROpts *checkPROptions
+
+func addCheckPRFlags(subcommand *cobra.Command) {
+	// githubBaseURL contains the github base URL.
+	subcommand.PersistentFlags().StringVar(
+		&checkPROpts.GithubBaseURL,
+		"github-base-url",
+		env.Default("GITHUB_BASE_URL", ""),
+		"Base URL of github",
+	)
+
+	// githubOrg contains name of github organization that holds the repo to scrape.
+	subcommand.PersistentFlags().StringVar(
+		&checkPROpts.GithubOrg,
+		"org",
+		env.Default("ORG", notes.DefaultOrg),
+		"Name of github organization",
+	)
+
+	// githubRepo contains name of github repository to scrape.
+	subcommand.PersistentFlags().StringVar(
+		&checkPROpts.GithubRepo,
+		"repo",
+		env.Default("REPO", notes.DefaultRepo),
+		"Name of github repository",
+	)
+
+	// Debug output
+	subcommand.PersistentFlags().BoolVar(
+		&checkPROpts.Debug,
+		"debug",
+		env.IsSet("DEBUG"),
+		"Enable debug logging",
+	)
+
+	subcommand.PersistentFlags().IntSliceVar(
+		&checkPROpts.PullRequests,
+		"pr",
+		[]int{},
+		"pull request number(s) to check",
+	)
+}
+
+func addCheckPR(parent *cobra.Command) {
+	checkPROpts = &checkPROptions{
+		Options: options.Options{},
+	}
+
+	checkprCmd := &cobra.Command{
+		Short: "Checks a pull request on GitHub to ensure it has a release note",
+		Long: `release-notes check checks one or more PRs to ensure they contain
+a valid release note. It is a subcommand designed to run in a postsubmit job to
+block PRs missing a release note.
+
+release-notes check will retrieve pull request data using the GitHub API and
+look for a valid release notes block in the PR body. For example:
+
+` + bkTicks + `release-note
+Fixed a bug to make my software even more awesome
+` + bkTicks + `
+
+When enforcing release notes in PRs, we recommend adding the release-notes block
+to your PR templates. See how Kubernetes does it here:
+https://github.com/kubernetes/release/blob/d546da8a2ec580ea4c024637234cc976a6ba398a/.github/PULL_REQUEST_TEMPLATE.md?plain=1#L45-L57
+
+If you want to skip the release notes check, you can create a new "release-notes-none"
+label to your PR or type "NONE" in the notes block:
+
+` + bkTicks + `release-note
+NONE
+` + bkTicks + `
+
+Either of these will instruct the release note checked to allow a PR without a
+valid note.
+
+To generate release notes from these blocks, use release-notes generate.
+
+
+		`,
+		Use:           "check",
+		SilenceUsage:  false,
+		SilenceErrors: false,
+		RunE: func(cmd *cobra.Command, args []string) error {
+			g, err := notes.NewGatherer(context.Background(), &options.Options{
+				GithubBaseURL: checkPROpts.GithubBaseURL,
+				GithubOrg:     checkPROpts.GithubOrg,
+				GithubRepo:    checkPROpts.GithubRepo,
+			})
+			if err != nil {
+				return fmt.Errorf("creating notes gatherer: %w", err)
+			}
+
+			errs := []error{}
+
+			for _, prNr := range checkPROpts.PullRequests {
+				_, err := g.ReleaseNoteForPullRequest(prNr)
+				if err != nil {
+					errs = append(errs, fmt.Errorf("checking notes for PR #%d: %w", prNr, err))
+				}
+			}
+
+			if len(errs) > 0 {
+				fmt.Fprintf(os.Stderr, "\nError Checking Release Notes:\n\n"+pullRequestGuidance)
+				return errors.Join(errs...)
+			}
+
+			return nil
+		},
+		PreRunE: func(*cobra.Command, []string) error {
+			return checkPROpts.ValidateAndFinish()
+		},
+	}
+
+	addCheckPRFlags(checkprCmd)
+	parent.AddCommand(checkprCmd)
+}

cmd/release-notes/check_test.go

@@ -0,0 +1,96 @@
+/*
+Copyright 2023 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 main
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+	"k8s.io/release/pkg/notes/options"
+)
+
+func TestPROptsValidateAndFinish(t *testing.T) {
+	testOrg := "testOrg"
+	testRepo := "testRepo"
+	for _, tc := range []struct {
+		name    string
+		sut     checkPROptions
+		mustErr bool
+	}{
+		{
+			name: "good options",
+			sut: checkPROptions{
+				Options: options.Options{
+					GithubOrg:  testOrg,
+					GithubRepo: testRepo,
+				},
+				PullRequests: []int{1, 2},
+			},
+			mustErr: false,
+		},
+		{
+			name: "missing repo",
+			sut: checkPROptions{
+				Options: options.Options{
+					GithubOrg: testOrg,
+				},
+				PullRequests: []int{1, 2},
+			},
+			mustErr: true,
+		},
+		{
+			name: "missing org",
+			sut: checkPROptions{
+				Options: options.Options{
+					GithubRepo: testRepo,
+				},
+				PullRequests: []int{1, 2},
+			},
+			mustErr: true,
+		},
+		{
+			name: "missing PRs",
+			sut: checkPROptions{
+				Options: options.Options{
+					GithubOrg:  testOrg,
+					GithubRepo: testRepo,
+				},
+				PullRequests: []int{},
+			},
+			mustErr: true,
+		},
+		{
+			name: "invalid PR",
+			sut: checkPROptions{
+				Options: options.Options{
+					GithubOrg:  testOrg,
+					GithubRepo: testRepo,
+				},
+				PullRequests: []int{0},
+			},
+			mustErr: true,
+		},
+	} {
+		t.Run(tc.name, func(t *testing.T) {
+			if tc.mustErr {
+				require.Error(t, tc.sut.ValidateAndFinish())
+			} else {
+				require.NoError(t, tc.sut.ValidateAndFinish())
+			}
+		})
+	}
+}