feat(Google email): Send email using gmail and passing by rabbitmq

example_consumer/.env.example

@@ -0,0 +1,4 @@
+LOG_LEVEL=debug
+RMQ_URL=amqp://guest:guest@localhost:5000/
+GOOGLE_CREDENTIAL=your-google-credential
+CLIENT_ID=your-client-id

example_consumer/go.mod

@@ -0,0 +1,58 @@
+module consumer
+
+go 1.23.3
+
+require (
+	github.com/lakhinsu/rabbitmq-go-example/consumer v0.0.0-20220116173101-cd008c3ff7d7
+	github.com/rs/zerolog v1.33.0
+	github.com/spf13/viper v1.19.0
+)
+
+require (
+	cloud.google.com/go/auth v0.11.0 // indirect
+	cloud.google.com/go/auth/oauth2adapt v0.2.6 // indirect
+	cloud.google.com/go/compute/metadata v0.5.2 // indirect
+	github.com/felixge/httpsnoop v1.0.4 // indirect
+	github.com/fsnotify/fsnotify v1.7.0 // indirect
+	github.com/go-logr/logr v1.4.2 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
+	github.com/google/s2a-go v0.1.8 // indirect
+	github.com/google/uuid v1.6.0 // indirect
+	github.com/googleapis/enterprise-certificate-proxy v0.3.4 // indirect
+	github.com/googleapis/gax-go/v2 v2.14.0 // indirect
+	github.com/hashicorp/hcl v1.0.0 // indirect
+	github.com/magiconair/properties v1.8.7 // indirect
+	github.com/mattn/go-colorable v0.1.13 // indirect
+	github.com/mattn/go-isatty v0.0.19 // indirect
+	github.com/mitchellh/mapstructure v1.5.0 // indirect
+	github.com/pelletier/go-toml/v2 v2.2.2 // indirect
+	github.com/rabbitmq/amqp091-go v1.10.0 // indirect
+	github.com/sagikazarmark/locafero v0.4.0 // indirect
+	github.com/sagikazarmark/slog-shim v0.1.0 // indirect
+	github.com/sourcegraph/conc v0.3.0 // indirect
+	github.com/spf13/afero v1.11.0 // indirect
+	github.com/spf13/cast v1.6.0 // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
+	github.com/streadway/amqp v1.0.0 // indirect
+	github.com/subosito/gotenv v1.6.0 // indirect
+	go.opencensus.io v0.24.0 // indirect
+	go.opentelemetry.io/contrib/instrumentation/net/http/otelhttp v0.57.0 // indirect
+	go.opentelemetry.io/otel v1.32.0 // indirect
+	go.opentelemetry.io/otel/metric v1.32.0 // indirect
+	go.opentelemetry.io/otel/trace v1.32.0 // indirect
+	go.uber.org/atomic v1.9.0 // indirect
+	go.uber.org/multierr v1.9.0 // indirect
+	golang.org/x/crypto v0.29.0 // indirect
+	golang.org/x/exp v0.0.0-20230905200255-921286631fa9 // indirect
+	golang.org/x/net v0.31.0 // indirect
+	golang.org/x/oauth2 v0.24.0 // indirect
+	golang.org/x/sys v0.27.0 // indirect
+	golang.org/x/text v0.20.0 // indirect
+	google.golang.org/api v0.209.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20241118233622-e639e219e697 // indirect
+	google.golang.org/grpc v1.68.0 // indirect
+	google.golang.org/protobuf v1.35.2 // indirect
+	gopkg.in/ini.v1 v1.67.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)

example_consumer/handlers/handlers.go

@@ -0,0 +1,31 @@
+package handlers
+
+import (
+	"consumer/service"
+	"consumer/utils"
+	amqp "github.com/rabbitmq/amqp091-go"
+	"github.com/rs/zerolog/log"
+	"strings"
+)
+
+func HandleMessage(queue string, msg amqp.Delivery, err error) {
+	if err != nil {
+		log.Err(err).Msg("Error occurred in RMQ consumer")
+	}
+	log.Info().Msgf("Message received on '%s' queue: %s", queue, string(msg.Body))
+
+	if strings.HasPrefix(string(msg.Body), "send email:") {
+		parts := strings.SplitN(string(msg.Body), ":", 2)
+		if len(parts) == 2 {
+			email := strings.TrimSpace(parts[1])
+			err := service.SendEmailTo(utils.Token, email)
+			if err != nil {
+				log.Err(err).Msg("Error sending email")
+			} else {
+				log.Info().Msgf("Email sent to %s", email)
+			}
+		} else {
+			log.Error().Msg("Invalid message format")
+		}
+	}
+}

example_consumer/main.go

@@ -0,0 +1,33 @@
+package main
+
+import (
+	"consumer/consts"
+	"consumer/handlers"
+	"consumer/utils"
+	"github.com/rs/zerolog/log"
+	"net/http"
+)
+
+func main() {
+	http.HandleFunc("/auth/google/login", utils.GetAuthURL)
+	http.HandleFunc("/auth/google/callback", utils.HandleGoogleCallback)
+	log.Info().Msg("Server started successfully on port http://localhost:8042")
+	log.Info().Msg("Login with Google at http://localhost:8042/auth/google/login")
+	log.Info().Msg("Callback URL: http://localhost:8042/auth/google/callback")
+	connectionString := utils.GetEnvVar("RMQ_URL")
+
+	messageQueue := utils.RMQConsumer{
+		Queue:            consts.MessageQueue,
+		ConnectionString: connectionString,
+		MsgHandler:       handlers.HandleMessage,
+	}
+	forever := make(chan bool)
+
+	go messageQueue.Consume()
+	err := http.ListenAndServe(":8042", nil)
+	if err != nil {
+		log.Fatal().Err(err).Msg("Server failed to start")
+	}
+	<-forever
+
+}

example_consumer/service/email.go

@@ -0,0 +1,29 @@
+package service
+
+import (
+	"consumer/utils"
+	"encoding/base64"
+	"fmt"
+	"golang.org/x/oauth2"
+	"google.golang.org/api/gmail/v1"
+)
+
+func SendEmailTo(token *oauth2.Token, toEmail string) error {
+	service, err := utils.InitGoogleAPI(token, "gmail")
+	if err != nil {
+		return err
+	}
+
+	gmailService := service.(*gmail.Service)
+	message := []byte(fmt.Sprintf("To: %s\r\nSubject: Test Email\r\n\r\nThis is a test email sent from AREA!", toEmail))
+	msg := gmail.Message{
+		Raw: base64.URLEncoding.EncodeToString(message),
+	}
+
+	_, err = gmailService.Users.Messages.Send("me", &msg).Do()
+	if err != nil {
+		return err
+	}
+
+	return nil
+}

example_consumer/utils/googleAuth.go

@@ -0,0 +1,107 @@
+package utils
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"github.com/lakhinsu/rabbitmq-go-example/consumer/utils"
+	"github.com/rs/zerolog/log"
+	"golang.org/x/oauth2"
+	"golang.org/x/oauth2/google"
+	"google.golang.org/api/gmail/v1"
+	"google.golang.org/api/option"
+	"google.golang.org/api/people/v1"
+	"net/http"
+	"time"
+)
+
+var (
+	Token        *oauth2.Token
+	refreshToken string
+)
+
+var config = &oauth2.Config{
+	RedirectURL:  "http://localhost:8042/auth/google/callback",
+	ClientID:     utils.GetEnvVar("CLIENT_ID"),
+	ClientSecret: utils.GetEnvVar("GOOGLE_CREDENTIAL"),
+	Scopes:       []string{"https://www.googleapis.com/auth/userinfo.profile", "https://www.googleapis.com/auth/userinfo.email", "https://www.googleapis.com/auth/gmail.send"},
+	Endpoint:     google.Endpoint,
+}
+
+func GetAuthURL(w http.ResponseWriter, r *http.Request) {
+	url := config.AuthCodeURL("state-token", oauth2.AccessTypeOffline)
+	http.Redirect(w, r, url, http.StatusTemporaryRedirect)
+}
+
+func RefreshToken() error {
+	ctx := context.Background()
+	token := &oauth2.Token{RefreshToken: refreshToken}
+	newToken, err := config.TokenSource(ctx, token).Token()
+	if err != nil {
+		return err
+	}
+	Token = newToken
+	return nil
+}
+
+func ExchangeCodeForToken(code string) (*oauth2.Token, error) {
+	ctx := context.Background()
+	token, err := config.Exchange(ctx, code)
+	if err != nil {
+		return nil, err
+	}
+	Token = token
+	refreshToken = token.RefreshToken
+	return token, nil
+}
+
+func InitGoogleAPI(token *oauth2.Token, apiName string) (interface{}, error) {
+	if Token.Expiry.Before(time.Now()) {
+		if err := RefreshToken(); err != nil {
+			return nil, err
+		}
+	}
+	ctx := context.Background()
+	httpClient := config.Client(ctx, token)
+
+	switch apiName {
+	case "gmail":
+		service, err := gmail.NewService(ctx, option.WithHTTPClient(httpClient))
+		if err != nil {
+			return nil, err
+		}
+		return service, nil
+	case "people":
+		service, err := people.NewService(ctx, option.WithHTTPClient(httpClient))
+		if err != nil {
+			return nil, err
+		}
+		return service, nil
+	default:
+		return nil, fmt.Errorf("unsupported API: %s", apiName)
+	}
+}
+
+func HandleGoogleCallback(w http.ResponseWriter, r *http.Request) {
+	code := r.FormValue("code")
+	_, err := ExchangeCodeForToken(code)
+	if err != nil {
+		http.Error(w, "Failed to exchange token", http.StatusInternalServerError)
+		return
+	}
+
+	response, err := http.Get("https://www.googleapis.com/oauth2/v2/userinfo?access_token=" + Token.AccessToken)
+	if err != nil {
+		http.Error(w, "Failed to get user info", http.StatusInternalServerError)
+		return
+	}
+	defer response.Body.Close()
+
+	var userInfo map[string]interface{}
+	err = json.NewDecoder(response.Body).Decode(&userInfo)
+	if err != nil {
+		http.Error(w, "Failed to decode user info", http.StatusInternalServerError)
+		return
+	}
+	log.Log().Msgf("User info: %+v", userInfo)
+}