feat(email): send email with gmail

Makefile

@@ -34,7 +34,7 @@ sqlc:
 		sqlc generate
 
 test:
-		go test -v -cover ./...
+		go test -v -cover -short ./...
 
 server:
 		go run main.go

app.env

@@ -6,4 +6,7 @@ GRPC_SERVER_ADDRESS=0.0.0.0:9090
 TOKEN_SYMMETRIC_KEY=12345678901234567890123456789012
 ACCESS_TOKEN_DURATION=15m
 REFRESH_TOKEN_DURATION=24h
-REDIS_ADDRESS=0.0.0.0:6379
+REDIS_ADDRESS=0.0.0.0:6379
+EMAIL_SENDER_NAME=Simple Bank
+EMAIL_SENDER_ADDRESS=[email protected]
+EMAIL_SENDER_PASSWORD=prgctnuzmwqlkcrn

go.mod

@@ -6,6 +6,7 @@ require (
 	github.com/aead/chacha20poly1305 v0.0.0-20170617001512-233f39982aeb
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.20.0
 	github.com/jackc/pgx/v5 v5.6.0
+	github.com/jordan-wright/email v4.0.1-0.20210109023952-943e75fe5223+incompatible
 	github.com/redis/go-redis/v9 v9.0.3
 	github.com/stretchr/testify v1.9.0
 	google.golang.org/genproto/googleapis/api v0.0.0-20240513163218-0867130af1f8

go.sum

@@ -97,6 +97,8 @@ github.com/jackc/pgx/v5 v5.6.0 h1:SWJzexBzPL5jb0GEsrPMLIsi/3jOo7RHlzTjcAeDrPY=
 github.com/jackc/pgx/v5 v5.6.0/go.mod h1:DNZ/vlrUnhWCoFGxHAG8U2ljioxukquj7utPDgtQdTw=
 github.com/jackc/puddle/v2 v2.2.1 h1:RhxXJtFG022u4ibrCSMSiu5aOq1i77R3OHKNJj77OAk=
 github.com/jackc/puddle/v2 v2.2.1/go.mod h1:vriiEXHvEE654aYKXXjOvZM39qJ0q+azkZFrfEOc3H4=
+github.com/jordan-wright/email v4.0.1-0.20210109023952-943e75fe5223+incompatible h1:jdpOPRN1zP63Td1hDQbZW73xKmzDvZHzVdNYxhnTMDA=
+github.com/jordan-wright/email v4.0.1-0.20210109023952-943e75fe5223+incompatible/go.mod h1:1c7szIrayyPPB/987hsnvNzLushdWf4o/79s3P08L8A=
 github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnrnM=
 github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHmT4TnhNGBo=
 github.com/klauspost/cpuid/v2 v2.0.9/go.mod h1:FInQzS24/EEf25PyTYn52gqo7WaD8xa0213Md/qVLRg=

mail/sender.go

@@ -0,0 +1,65 @@
+package mail
+
+import (
+	"fmt"
+	"net/smtp"
+
+	"github.com/jordan-wright/email"
+)
+
+const (
+	smtpAuthAddress   = "smtp.gmail.com"
+	smtpServerAddress = "smtp.gmail.com:587"
+)
+
+type EmailSender interface {
+	SendEmail(
+		subject string,
+		content string,
+		to []string,
+		cc []string,
+		bcc []string,
+		attachFiles []string,
+	) error
+}
+
+type GmailSender struct {
+	name              string
+	fromEmailAddress  string
+	fromEmailPassword string
+}
+
+func NewGmailSender(name string, fromEmailAddress string, fromEmailPassword string) EmailSender {
+	return &GmailSender{
+		name:              name,
+		fromEmailAddress:  fromEmailAddress,
+		fromEmailPassword: fromEmailPassword,
+	}
+}
+
+func (sender *GmailSender) SendEmail(
+	subject string,
+	content string,
+	to []string,
+	cc []string,
+	bcc []string,
+	attachFiles []string,
+) error {
+	e := email.NewEmail()
+	e.From = fmt.Sprintf("%s <%s>", sender.name, sender.fromEmailAddress)
+	e.Subject = subject
+	e.HTML = []byte(content)
+	e.To = to
+	e.Cc = cc
+	e.Bcc = bcc
+
+	for _, f := range attachFiles {
+		_, err := e.AttachFile(f)
+		if err != nil {
+			return fmt.Errorf("failed to attach file %s: %w", f, err)
+		}
+	}
+
+	smtpAuth := smtp.PlainAuth("", sender.fromEmailAddress, sender.fromEmailPassword, smtpAuthAddress)
+	return e.Send(smtpServerAddress, smtpAuth)
+}

mail/sender_test.go

@@ -0,0 +1,30 @@
+package mail
+
+import (
+	"testing"
+
+	"github.com/eizyc/simplebank/util"
+	"github.com/stretchr/testify/require"
+)
+
+func TestSendEmailWithGmail(t *testing.T) {
+	if testing.Short() {
+		t.Skip()
+	}
+
+	config, err := util.LoadConfig("..")
+	require.NoError(t, err)
+
+	sender := NewGmailSender(config.EmailSenderName, config.EmailSenderAddress, config.EmailSenderPassword)
+
+	subject := "A test email"
+	content := `
+	<h1>Hello world</h1>
+	<p>This is a test message from <a href="https://eizyc.github.io/">Eizyc</a></p>
+	`
+	to := []string{"[email protected]"}
+	attachFiles := []string{"../README.md"}
+
+	err = sender.SendEmail(subject, content, to, nil, nil, attachFiles)
+	require.NoError(t, err)
+}

util/config.go

@@ -19,6 +19,9 @@ type Config struct {
 	AccessTokenDuration  time.Duration `mapstructure:"ACCESS_TOKEN_DURATION"`
 	RefreshTokenDuration time.Duration `mapstructure:"REFRESH_TOKEN_DURATION"`
 	RedisAddress         string        `mapstructure:"REDIS_ADDRESS"`
+	EmailSenderName      string        `mapstructure:"EMAIL_SENDER_NAME"`
+	EmailSenderAddress   string        `mapstructure:"EMAIL_SENDER_ADDRESS"`
+	EmailSenderPassword  string        `mapstructure:"EMAIL_SENDER_PASSWORD"`
 }
 
 // LoadConfig reads configuration from file or environment variables.