add custom email auth template

README.md

@@ -149,6 +149,7 @@ _this is the recommended way to run remark42_
 | auth.email.user         | AUTH_EMAIL_USER         |                          | smtp user name                                   |
 | auth.email.passwd       | AUTH_EMAIL_PASSWD       |                          | smtp password                                    |
 | auth.email.timeout      | AUTH_EMAIL_TIMEOUT      | `10s`                    | smtp timeout                                     |
+| auth.email.template     | AUTH_EMAIL_TEMPLATE     | none (predefined)        | custom email message template                    |   
 | notify.type             | NOTIFY_TYPE             | none                     | type of notification (none or telegram)          |
 | notify.queue            | NOTIFY_QUEUE            | `100`                    | size of notification queue                       |
 | notify.telegram.token   | NOTIFY_TELEGRAM_TOKEN   |                          | telegram token                                   |

backend/app/cmd/server.go

@@ -3,6 +3,7 @@ package cmd
 import (
 	"context"
 	"fmt"
+	"io/ioutil"
 	"net/http"
 	"net/url"
 	"os"
@@ -92,6 +93,7 @@ type ServerCommand struct {
 			SMTPUserName string        `long:"user" env:"USER" description:"smtp user name"`
 			SMTPPassword string        `long:"passwd" env:"PASSWD" description:"smtp password"`
 			TimeOut      time.Duration `long:"timeout" env:"TIMEOUT" default:"10s" description:"smtp timeout"`
+			MsgTemplate  string        `long:"template" env:"TEMPLATE" description:"message template file"`
 		} `group:"email" namespace:"email" env-namespace:"EMAIL"`
 	} `group:"auth" namespace:"auth" env-namespace:"AUTH"`
 
@@ -600,7 +602,7 @@ func (s *ServerCommand) addAuthProviders(authenticator *auth.Service) {
 			TimeOut:      s.Auth.Email.TimeOut,
 		}
 		sndr := sender.NewEmailClient(params, log.Default())
-		authenticator.AddVerifProvider("email", msgTemplate, sndr)
+		authenticator.AddVerifProvider("email", s.loadEmailTemplate(), sndr)
 	}
 
 	if s.Auth.Anonymous {
@@ -626,6 +628,22 @@ func (s *ServerCommand) addAuthProviders(authenticator *auth.Service) {
 	}
 }
 
+// loadEmailTemplate trying to get template from opts MsgTemplate and default to embedded
+// if not defined or failed to load
+func (s *ServerCommand) loadEmailTemplate() string {
+	tmpl := msgTemplate
+	if s.Auth.Email.MsgTemplate != "" {
+		log.Printf("[DEBUG] load email template from %s", s.Auth.Email.MsgTemplate)
+		b, err := ioutil.ReadFile(s.Auth.Email.MsgTemplate)
+		if err == nil {
+			tmpl = string(b)
+		} else {
+			log.Printf("[WARN] failed to load email template from %s, %v", s.Auth.Email.MsgTemplate, err)
+		}
+	}
+	return tmpl
+}
+
 func (s *ServerCommand) makeNotify(dataStore *service.DataStore) (*notify.Service, error) {
 	log.Printf("[INFO] make notify, type=%s", s.Notify.Type)
 	switch s.Notify.Type {

backend/app/cmd/server_test.go

@@ -431,6 +431,21 @@ func TestServerAuthHooks(t *testing.T) {
 	app.Wait()
 }
 
+func TestServer_loadEmailTemplate(t *testing.T) {
+	cmd := ServerCommand{}
+	cmd.Auth.Email.MsgTemplate = "testdata/email.tmpl"
+	r := cmd.loadEmailTemplate()
+	assert.Equal(t, "The token is {{.Token}}", r)
+
+	cmd.Auth.Email.MsgTemplate = ""
+	r = cmd.loadEmailTemplate()
+	assert.Contains(t, r, "Remark42</h1>")
+
+	cmd.Auth.Email.MsgTemplate = "bad-file"
+	r = cmd.loadEmailTemplate()
+	assert.Contains(t, r, "Remark42</h1>")
+}
+
 func prepServerApp(t *testing.T, duration time.Duration, fn func(o ServerCommand) ServerCommand) (*serverApp, context.Context) {
 	cmd := ServerCommand{}
 	cmd.SetCommon(CommonOpts{RemarkURL: "https://demo.remark42.com", SharedSecret: "secret"})
@@ -446,6 +461,8 @@ func prepServerApp(t *testing.T, duration time.Duration, fn func(o ServerCommand
 	cmd.Auth.Google.CSEC, cmd.Auth.Google.CID = "csec", "cid"
 	cmd.Auth.Facebook.CSEC, cmd.Auth.Facebook.CID = "csec", "cid"
 	cmd.Auth.Yandex.CSEC, cmd.Auth.Yandex.CID = "csec", "cid"
+	cmd.Auth.Email.Enable = true
+	cmd.Auth.Email.MsgTemplate = "testdata/email.tmpl"
 	cmd.BackupLocation = "/tmp"
 	cmd.Notify.Type = "telegram"
 	cmd.Notify.Telegram.API = "http://127.0.0.1:12340/"

backend/app/cmd/testdata/email.tmpl

@@ -0,0 +1 @@
+The token is {{.Token}}