add aws lambda function to send patch cherry pick notification

cmd/patch-release-notification/README.md

@@ -0,0 +1,4 @@
+# Patch Release Notification
+
+This simple tool has the objective to send an notification email when we are closer to
+the patch release cycle to let people know that the cherry pick deadline is approaching.

cmd/patch-release-notification/main.go

@@ -0,0 +1,315 @@
+/*
+Copyright 2024 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 (
+	"bytes"
+	"context"
+	"embed"
+	"fmt"
+	"io"
+	"math"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+	"text/template"
+	"time"
+
+	"gomodules.xyz/envconfig"
+	"gopkg.in/gomail.v2"
+	"gopkg.in/yaml.v3"
+
+	"github.com/aws/aws-lambda-go/events"
+	"github.com/aws/aws-lambda-go/lambda"
+	"github.com/aws/aws-sdk-go/aws"
+	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/aws/aws-sdk-go/service/ses"
+	"github.com/sirupsen/logrus"
+
+	"k8s.io/release/cmd/schedule-builder/model"
+)
+
+//go:embed templates/email.tmpl
+var tpls embed.FS
+
+type Config struct {
+	FromEmail    string `envconfig:"FROM_EMAIL"    required:"true"`
+	ToEmail      string `envconfig:"TO_EMAIL"      required:"true"`
+	SchedulePath string `envconfig:"SCHEDULE_PATH" required:"true"`
+	DaysToAlert  int    `envconfig:"DAYS_TO_ALERT" required:"true"`
+
+	NoMock bool `default:"false" envconfig:"NO_MOCK" required:"true"`
+
+	AWSRegion string `envconfig:"AWS_REGION" required:"true"`
+}
+
+type Options struct {
+	AWSSess *session.Session
+	Config  *Config
+	Context context.Context
+}
+
+const (
+	layout = "2006-01-02"
+)
+
+type Template struct {
+	Releases []TemplateRelease
+}
+
+type TemplateRelease struct {
+	Release            string
+	CherryPickDeadline string
+}
+
+func main() {
+	lambda.Start(handler)
+}
+
+func getConfig() (*Config, error) {
+	var c Config
+	err := envconfig.Process("", &c)
+	if err != nil {
+		return nil, err
+	}
+	return &c, nil
+}
+
+func NewOptions(ctx context.Context) (*Options, error) {
+	config, err := getConfig()
+	if err != nil {
+		return nil, fmt.Errorf("failed to get config: %w", err)
+	}
+
+	// create new AWS session
+	sess, err := session.NewSession(&aws.Config{
+		Region: aws.String(config.AWSRegion),
+	})
+	if err != nil {
+		return nil, err
+	}
+
+	return &Options{
+		AWSSess: sess,
+		Config:  config,
+		Context: ctx,
+	}, nil
+}
+
+func handler(ctx context.Context, request events.APIGatewayProxyRequest) (events.APIGatewayProxyResponse, error) { //nolint: gocritic
+	o, err := NewOptions(ctx)
+	if err != nil {
+		return events.APIGatewayProxyResponse{
+			Body:       `{"status": "nok"}`,
+			StatusCode: http.StatusInternalServerError,
+		}, err
+	}
+
+	logrus.Infof("Will pull the patch release schedule from: %s", o.Config.SchedulePath)
+	data, err := loadFileOrURL(o.Config.SchedulePath)
+	if err != nil {
+		return events.APIGatewayProxyResponse{
+			Body:       `{"status": "nok"}`,
+			StatusCode: http.StatusInternalServerError,
+		}, fmt.Errorf("reading the file: %w", err)
+	}
+
+	patchSchedule := &model.PatchSchedule{}
+
+	logrus.Info("Parsing the schedule...")
+
+	if err := yaml.Unmarshal(data, &patchSchedule); err != nil {
+		return events.APIGatewayProxyResponse{
+			Body:       `{"status": "nok"}`,
+			StatusCode: http.StatusInternalServerError,
+		}, fmt.Errorf("decoding the file: %w", err)
+	}
+
+	output := &Template{}
+
+	shouldSendEmail := false
+
+	for _, patch := range patchSchedule.Schedules {
+		t, err := time.Parse(layout, patch.Next.CherryPickDeadline)
+		if err != nil {
+			return events.APIGatewayProxyResponse{
+				Body:       `{"status": "nok"}`,
+				StatusCode: http.StatusInternalServerError,
+			}, fmt.Errorf("parsing schedule time: %w", err)
+		}
+
+		currentTime := time.Now().UTC()
+		days := t.Sub(currentTime).Hours() / 24
+		intDay, _ := math.Modf(days)
+		logrus.Infof("Cherry pick deadline: %d, days to alert: %d", int(intDay), o.Config.DaysToAlert)
+		if int(intDay) == o.Config.DaysToAlert {
+			output.Releases = append(output.Releases, TemplateRelease{
+				Release:            patch.Release,
+				CherryPickDeadline: patch.Next.CherryPickDeadline,
+			})
+			shouldSendEmail = true
+		}
+	}
+
+	if !shouldSendEmail {
+		logrus.Info("No email is needed to send")
+		return events.APIGatewayProxyResponse{
+			Body:       `{"status": "ok"}`,
+			StatusCode: http.StatusOK,
+		}, nil
+	}
+
+	tmpl, err := template.ParseFS(tpls, "templates/email.tmpl")
+	if err != nil {
+		return events.APIGatewayProxyResponse{
+			Body:       `{"status": "nok"}`,
+			StatusCode: http.StatusInternalServerError,
+		}, fmt.Errorf("parsing template: %w", err)
+	}
+
+	var tmplBytes bytes.Buffer
+	err = tmpl.Execute(&tmplBytes, output)
+	if err != nil {
+		return events.APIGatewayProxyResponse{
+			Body:       `{"status": "nok"}`,
+			StatusCode: http.StatusInternalServerError,
+		}, fmt.Errorf("executing the template: %w", err)
+	}
+
+	logrus.Info("Sending mail")
+	subject := "[Please Read] Upcoming Patch Releases Cherry-Pick Deadline for Kubernetes"
+	fromEmail := o.Config.FromEmail
+
+	recipient := Recipient{
+		toEmails: []string{o.Config.ToEmail},
+	}
+
+	if !o.Config.NoMock {
+		logrus.Info("This is a mock only, will print out the email before sending to a test mailing list")
+		fmt.Println(tmplBytes.String())
+		// if is a mock we send the email to ourselves to test
+		recipient.toEmails = []string{o.Config.FromEmail}
+	}
+
+	err = o.SendEmailRawSES(tmplBytes.String(), subject, fromEmail, recipient)
+	if err != nil {
+		return events.APIGatewayProxyResponse{
+			Body:       `{"status": "nok"}`,
+			StatusCode: http.StatusInternalServerError,
+		}, fmt.Errorf("sending the email: %w", err)
+	}
+
+	return events.APIGatewayProxyResponse{
+		Body:       `{"status": "ok"}`,
+		StatusCode: 200,
+	}, nil
+}
+
+// Recipient struct to hold email IDs
+type Recipient struct {
+	toEmails  []string
+	ccEmails  []string
+	bccEmails []string
+}
+
+// SendEmailSES sends email to specified email IDs
+func (o *Options) SendEmailRawSES(messageBody, subject, fromEmail string, recipient Recipient) error {
+	// create raw message
+	msg := gomail.NewMessage()
+
+	// set to section
+	recipients := make([]*string, 0, len(recipient.toEmails))
+	for _, r := range recipient.toEmails {
+		recipient := r
+		recipients = append(recipients, &recipient)
+	}
+
+	// cc mails mentioned
+	if len(recipient.ccEmails) != 0 {
+		// Need to add cc mail IDs also in recipient list
+		for _, r := range recipient.ccEmails {
+			recipient := r
+			recipients = append(recipients, &recipient)
+		}
+		msg.SetHeader("cc", recipient.ccEmails...)
+	}
+
+	// bcc mails mentioned
+	if len(recipient.bccEmails) != 0 {
+		// Need to add bcc mail IDs also in recipient list
+		for _, r := range recipient.bccEmails {
+			recipient := r
+			recipients = append(recipients, &recipient)
+		}
+		msg.SetHeader("bcc", recipient.bccEmails...)
+	}
+
+	// create an SES session.
+	svc := ses.New(o.AWSSess)
+
+	msg.SetAddressHeader("From", fromEmail, "Release Managers")
+	msg.SetHeader("To", recipient.toEmails...)
+	msg.SetHeader("Subject", subject)
+	msg.SetBody("text/html", messageBody)
+
+	// create a new buffer to add raw data
+	var emailRaw bytes.Buffer
+	_, err := msg.WriteTo(&emailRaw)
+	if err != nil {
+		logrus.Errorf("Failed to write mail: %v", err)
+		return err
+	}
+
+	// create new raw message
+	message := ses.RawMessage{Data: emailRaw.Bytes()}
+
+	input := &ses.SendRawEmailInput{Source: &fromEmail, Destinations: recipients, RawMessage: &message}
+
+	// send raw email
+	_, err = svc.SendRawEmail(input)
+	if err != nil {
+		logrus.Errorf("Error sending mail - %v", err)
+		return err
+	}
+
+	logrus.Infof("Email sent successfully to: %q", recipient.toEmails)
+	return nil
+}
+
+func loadFileOrURL(fileRef string) ([]byte, error) {
+	var raw []byte
+	var err error
+	if strings.HasPrefix(fileRef, "http://") || strings.HasPrefix(fileRef, "https://") {
+		resp, err := http.Get(fileRef) //nolint:gosec // we are not using user input we set via env var
+		if err != nil {
+			return nil, err
+		}
+		defer resp.Body.Close()
+		raw, err = io.ReadAll(resp.Body)
+		if err != nil {
+			return nil, err
+		}
+	} else {
+		raw, err = os.ReadFile(filepath.Clean(fileRef))
+		if err != nil {
+			return nil, err
+		}
+	}
+
+	return raw, nil
+}

cmd/patch-release-notification/templates/email.tmpl

@@ -0,0 +1,32 @@
+<!DOCTYPE html>
+<html>
+<body>
+<p>Hello Kubernetes Community!</p>
+{{range .Releases}}
+<p>The cherry-pick deadline for the <b>{{ .Release }}</b> branches is <b>{{ .CherryPickDeadline }} EOD PT.</b></p>
+{{end}}
+<br><p>Here are some quick links to search for cherry-pick PRs:</p>
+{{range .Releases}}
+<p> - <a href="https://github.com/kubernetes/kubernetes/pulls?q=is%3Apr+is%3Aopen+base%3Arelease-{{ .Release }}+label%3Ado-not-merge%2Fcherry-pick-not-approved">Check PRs for release-{{ .Release }}</a></p>
+{{end}}
+<br>
+<p>For PRs that you intend to land for the upcoming patch sets, please
+ensure they have:</p>
+<p> - a release note in the PR description</p>
+<p> - /sig</p>
+<p> - /kind</p>
+<p> - /priority</p>
+<p> - /lgtm</p>
+<p> - /approve</p>
+<p> - passing tests and not on hold.</p>
+<br>
+<p>Details on the cherry-pick process can be found here:</p>
+<p>https://git.k8s.io/community/contributors/devel/sig-release/cherry-picks.md</p>
+<p>We keep general info and up-to-date timelines for patch releases here:</p>
+<p>https://kubernetes.io/releases/patch-releases/#upcoming-monthly-releases</p>
+<p>If you have any questions for the Release Managers, please feel free to
+reach out to us at #release-management (Kubernetes Slack) or [email protected]</p><br>
+<p>We wish everyone a happy and safe week!</p>
+<p>SIG Release Team</p>
+</body>
+</html>