feat: mailer logging (#1805)

This is a quick patch to add basic logging information to the mailer
package.

I wasn't sure how to only log this information when using the Supabase
default mail provider without adding another custom config flag to
enable it.

---------

Co-authored-by: Chris Stockton <[email protected]>

Author: cstockton

internal/conf/configuration.go

@@ -342,14 +342,15 @@ type ProviderConfiguration struct {
 }
 
 type SMTPConfiguration struct {
-	MaxFrequency time.Duration `json:"max_frequency" split_words:"true"`
-	Host         string        `json:"host"`
-	Port         int           `json:"port,omitempty" default:"587"`
-	User         string        `json:"user"`
-	Pass         string        `json:"pass,omitempty"`
-	AdminEmail   string        `json:"admin_email" split_words:"true"`
-	SenderName   string        `json:"sender_name" split_words:"true"`
-	Headers      string        `json:"headers"`
+	MaxFrequency   time.Duration `json:"max_frequency" split_words:"true"`
+	Host           string        `json:"host"`
+	Port           int           `json:"port,omitempty" default:"587"`
+	User           string        `json:"user"`
+	Pass           string        `json:"pass,omitempty"`
+	AdminEmail     string        `json:"admin_email" split_words:"true"`
+	SenderName     string        `json:"sender_name" split_words:"true"`
+	Headers        string        `json:"headers"`
+	LoggingEnabled bool          `json:"logging_enabled" split_words:"true" default:"false"`
 
 	fromAddress       string              `json:"-"`
 	normalizedHeaders map[string][]string `json:"-"`

internal/conf/configuration_test.go

@@ -23,8 +23,12 @@ func TestGlobal(t *testing.T) {
 	os.Setenv("API_EXTERNAL_URL", "http://localhost:9999")
 	os.Setenv("GOTRUE_HOOK_MFA_VERIFICATION_ATTEMPT_URI", "pg-functions://postgres/auth/count_failed_attempts")
 	os.Setenv("GOTRUE_HOOK_SEND_SMS_SECRETS", "v1,whsec_aWxpa2VzdXBhYmFzZXZlcnltdWNoYW5kaWhvcGV5b3Vkb3Rvbw==")
+	os.Setenv("GOTRUE_SMTP_HEADERS", `{"X-PM-Metadata-project-ref":["project_ref"],"X-SES-Message-Tags":["ses:feedback-id-a=project_ref,ses:feedback-id-b=$messageType"]}`)
+	os.Setenv("GOTRUE_SMTP_LOGGING_ENABLED", "true")
 	gc, err := LoadGlobal("")
 	require.NoError(t, err)
+	assert.Equal(t, true, gc.SMTP.LoggingEnabled)
+	assert.Equal(t, "project_ref", gc.SMTP.NormalizedHeaders()["X-PM-Metadata-project-ref"][0])
 	require.NotNil(t, gc)
 	assert.Equal(t, "X-Request-ID", gc.API.RequestIDHeader)
 	assert.Equal(t, "pg-functions://postgres/auth/count_failed_attempts", gc.Hook.MFAVerificationAttempt.URI)

internal/mailer/mailer.go

@@ -49,14 +49,15 @@ func NewMailer(globalConfig *conf.GlobalConfiguration) Mailer {
 		mailClient = &noopMailClient{}
 	} else {
 		mailClient = &MailmeMailer{
-			Host:      globalConfig.SMTP.Host,
-			Port:      globalConfig.SMTP.Port,
-			User:      globalConfig.SMTP.User,
-			Pass:      globalConfig.SMTP.Pass,
-			LocalName: u.Hostname(),
-			From:      from,
-			BaseURL:   globalConfig.SiteURL,
-			Logger:    logrus.StandardLogger(),
+			Host:        globalConfig.SMTP.Host,
+			Port:        globalConfig.SMTP.Port,
+			User:        globalConfig.SMTP.User,
+			Pass:        globalConfig.SMTP.Pass,
+			LocalName:   u.Hostname(),
+			From:        from,
+			BaseURL:     globalConfig.SiteURL,
+			Logger:      logrus.StandardLogger(),
+			MailLogging: globalConfig.SMTP.LoggingEnabled,
 		}
 	}
 

internal/mailer/mailme.go

@@ -24,21 +24,22 @@ const TemplateExpiration = 10 * time.Second
 
 // MailmeMailer lets MailMe send templated mails
 type MailmeMailer struct {
-	From      string
-	Host      string
-	Port      int
-	User      string
-	Pass      string
-	BaseURL   string
-	LocalName string
-	FuncMap   template.FuncMap
-	cache     *TemplateCache
-	Logger    logrus.FieldLogger
+	From        string
+	Host        string
+	Port        int
+	User        string
+	Pass        string
+	BaseURL     string
+	LocalName   string
+	FuncMap     template.FuncMap
+	cache       *TemplateCache
+	Logger      logrus.FieldLogger
+	MailLogging bool
 }
 
 // Mail sends a templated mail. It will try to load the template from a URL, and
 // otherwise fall back to the default
-func (m *MailmeMailer) Mail(to, subjectTemplate, templateURL, defaultTemplate string, templateData map[string]interface{}, headers map[string][]string) error {
+func (m *MailmeMailer) Mail(to, subjectTemplate, templateURL, defaultTemplate string, templateData map[string]interface{}, headers map[string][]string, typ string) error {
 	if m.FuncMap == nil {
 		m.FuncMap = map[string]interface{}{}
 	}
@@ -60,6 +61,7 @@ func (m *MailmeMailer) Mail(to, subjectTemplate, templateURL, defaultTemplate st
 	if err != nil {
 		return err
 	}
+
 	body, err := m.MailBody(templateURL, defaultTemplate, templateData)
 	if err != nil {
 		return err
@@ -82,8 +84,22 @@ func (m *MailmeMailer) Mail(to, subjectTemplate, templateURL, defaultTemplate st
 	if m.LocalName != "" {
 		dial.LocalName = m.LocalName
 	}
-	return dial.DialAndSend(mail)
 
+	if m.MailLogging {
+		defer func() {
+			fields := logrus.Fields{
+				"event":     "mail.send",
+				"mail_type": typ,
+				"mail_from": m.From,
+				"mail_to":   to,
+			}
+			m.Logger.WithFields(fields).Info("mail.send")
+		}()
+	}
+	if err := dial.DialAndSend(mail); err != nil {
+		return err
+	}
+	return nil
 }
 
 type MailTemplate struct {

internal/mailer/noop.go

@@ -6,7 +6,7 @@ import (
 
 type noopMailClient struct{}
 
-func (m *noopMailClient) Mail(to, subjectTemplate, templateURL, defaultTemplate string, templateData map[string]interface{}, headers map[string][]string) error {
+func (m *noopMailClient) Mail(to, subjectTemplate, templateURL, defaultTemplate string, templateData map[string]interface{}, headers map[string][]string, typ string) error {
 	if to == "" {
 		return errors.New("to field cannot be empty")
 	}

internal/mailer/template.go

@@ -12,7 +12,7 @@ import (
 )
 
 type MailClient interface {
-	Mail(string, string, string, string, map[string]interface{}, map[string][]string) error
+	Mail(string, string, string, string, map[string]interface{}, map[string][]string, string) error
 }
 
 // TemplateMailer will send mail and use templates from the site for easy mail styling
@@ -151,6 +151,7 @@ func (m *TemplateMailer) InviteMail(r *http.Request, user *models.User, otp, ref
 		defaultInviteMail,
 		data,
 		m.Headers("invite"),
+		"invite",
 	)
 }
 
@@ -182,6 +183,7 @@ func (m *TemplateMailer) ConfirmationMail(r *http.Request, user *models.User, ot
 		defaultConfirmationMail,
 		data,
 		m.Headers("confirm"),
+		"confirm",
 	)
 }
 
@@ -201,6 +203,7 @@ func (m *TemplateMailer) ReauthenticateMail(r *http.Request, user *models.User,
 		defaultReauthenticateMail,
 		data,
 		m.Headers("reauthenticate"),
+		"reauthenticate",
 	)
 }
 
@@ -266,6 +269,7 @@ func (m *TemplateMailer) EmailChangeMail(r *http.Request, user *models.User, otp
 				defaultEmailChangeMail,
 				data,
 				m.Headers("email_change"),
+				"email_change",
 			)
 		}(email.Address, email.Otp, email.TokenHash, email.Template)
 	}
@@ -307,6 +311,7 @@ func (m *TemplateMailer) RecoveryMail(r *http.Request, user *models.User, otp, r
 		defaultRecoveryMail,
 		data,
 		m.Headers("recovery"),
+		"recovery",
 	)
 }
 
@@ -338,6 +343,7 @@ func (m *TemplateMailer) MagicLinkMail(r *http.Request, user *models.User, otp,
 		defaultMagicLinkMail,
 		data,
 		m.Headers("magiclink"),
+		"magiclink",
 	)
 }
 
@@ -350,6 +356,7 @@ func (m TemplateMailer) Send(user *models.User, subject, body string, data map[s
 		body,
 		data,
 		m.Headers("other"),
+		"other",
 	)
 }
 

internal/mailer/template_test.go

@@ -8,23 +8,58 @@ import (
 )
 
 func TestTemplateHeaders(t *testing.T) {
-	mailer := TemplateMailer{
-		Config: &conf.GlobalConfiguration{
-			SMTP: conf.SMTPConfiguration{
-				Headers: `{"X-Test-A": ["test-a", "test-b"], "X-Test-B": ["test-c", "abc $messageType"]}`,
+	cases := []struct {
+		from string
+		typ  string
+		exp  map[string][]string
+	}{
+		{
+			from: `{"x-supabase-project-ref": ["abcjrhohrqmvcpjpsyzc"]}`,
+			typ:  "OTHER-TYPE",
+			exp: map[string][]string{
+				"x-supabase-project-ref": {"abcjrhohrqmvcpjpsyzc"},
 			},
 		},
-	}
 
-	require.NoError(t, mailer.Config.SMTP.Validate())
+		{
+			from: `{"X-Test-A": ["test-a", "test-b"], "X-Test-B": ["test-c", "abc $messageType"]}`,
+			typ:  "TEST-MESSAGE-TYPE",
+			exp: map[string][]string{
+				"X-Test-A": {"test-a", "test-b"},
+				"X-Test-B": {"test-c", "abc TEST-MESSAGE-TYPE"},
+			},
+		},
 
-	require.Equal(t, mailer.Headers("TEST-MESSAGE-TYPE"), map[string][]string{
-		"X-Test-A": {"test-a", "test-b"},
-		"X-Test-B": {"test-c", "abc TEST-MESSAGE-TYPE"},
-	})
+		{
+			from: `{"X-Test-A": ["test-a", "test-b"], "X-Test-B": ["test-c", "abc $messageType"]}`,
+			typ:  "OTHER-TYPE",
+			exp: map[string][]string{
+				"X-Test-A": {"test-a", "test-b"},
+				"X-Test-B": {"test-c", "abc OTHER-TYPE"},
+			},
+		},
 
-	require.Equal(t, mailer.Headers("OTHER-TYPE"), map[string][]string{
-		"X-Test-A": {"test-a", "test-b"},
-		"X-Test-B": {"test-c", "abc OTHER-TYPE"},
-	})
+		{
+			from: `{"X-Test-A": ["test-a", "test-b"], "X-Test-B": ["test-c", "abc $messageType"], "x-supabase-project-ref": ["abcjrhohrqmvcpjpsyzc"]}`,
+			typ:  "OTHER-TYPE",
+			exp: map[string][]string{
+				"X-Test-A":               {"test-a", "test-b"},
+				"X-Test-B":               {"test-c", "abc OTHER-TYPE"},
+				"x-supabase-project-ref": {"abcjrhohrqmvcpjpsyzc"},
+			},
+		},
+	}
+	for _, tc := range cases {
+		mailer := TemplateMailer{
+			Config: &conf.GlobalConfiguration{
+				SMTP: conf.SMTPConfiguration{
+					Headers: tc.from,
+				},
+			},
+		}
+		require.NoError(t, mailer.Config.SMTP.Validate())
+
+		hdrs := mailer.Headers(tc.typ)
+		require.Equal(t, hdrs, tc.exp)
+	}
 }