feature: use embedded folder to load html templates (#30)

* using embedded folder to load html templates and protect available templates with a private variable and a getter to prevent sets
* remove copy assets to final stage of docker image build

Dockerfile

@@ -26,7 +26,4 @@ RUN apt-get update && \
 WORKDIR /app
 COPY --from=builder /src/backend ./
 
-# Include the assets folder
-COPY --from=builder /src/assets ./assets
-
 ENTRYPOINT ["/app/backend"]

api/users_test.go

@@ -22,7 +22,7 @@ func init() {
 	// create a regex to find the verification code in the email
 	codeRgx := fmt.Sprintf(`(.{%d})`, VerificationCodeLength*2)
 	// load the email templates
-	if err := mailtemplates.Load("../assets"); err != nil {
+	if err := mailtemplates.Load(); err != nil {
 		panic(err)
 	}
 	// wrap the mail template execution to force plain body and set the regex

cmd/service/main.go

@@ -1,7 +1,6 @@
 package main
 
 import (
-	"fmt"
 	"os"
 	"os/signal"
 	"syscall"
@@ -30,7 +29,6 @@ func main() {
 	flag.StringP("mongoDB", "d", "saasdb", "The name of the MongoDB database")
 	flag.StringP("privateKey", "k", "", "private key for the Vocdoni account")
 	flag.BoolP("fullTransparentMode", "a", false, "allow all transactions and do not modify any of them")
-	flag.String("emailTemplatesPath", "./assets", "path to the email templates")
 	flag.String("smtpServer", "", "SMTP server")
 	flag.Int("smtpPort", 587, "SMTP port")
 	flag.String("smtpUsername", "", "SMTP username")
@@ -60,7 +58,6 @@ func main() {
 	mongoURL := viper.GetString("mongoURL")
 	mongoDB := viper.GetString("mongoDB")
 	// email vars
-	emailTemplatesPath := viper.GetString("emailTemplatesPath")
 	smtpServer := viper.GetString("smtpServer")
 	smtpPort := viper.GetInt("smtpPort")
 	smtpUsername := viper.GetString("smtpUsername")
@@ -136,16 +133,12 @@ func main() {
 		}); err != nil {
 			log.Fatalf("could not create the email service: %v", err)
 		}
-		// load email templates if the path is set
-		if emailTemplatesPath != "" {
-			if err := mailtemplates.Load(emailTemplatesPath); err != nil {
-				log.Fatalf("could not load email templates: %v", err)
-			}
-			log.Infow("email templates loaded",
-				"path", emailTemplatesPath,
-				"templates", len(mailtemplates.AvailableTemplates))
+		// load email templates
+		if err := mailtemplates.Load(); err != nil {
+			log.Fatalf("could not load email templates: %v", err)
 		}
-		log.Infow("email service created", "from", fmt.Sprintf("%s <%s>", emailFromName, emailFromAddress))
+		log.Infow("email templates loaded",
+			"templates", len(mailtemplates.Available()))
 	}
 	subscriptions := subscriptions.New(&subscriptions.SubscriptionsConfig{
 		DB: database,

notifications/mailtemplates/templates.go

@@ -4,17 +4,16 @@ import (
 	"bytes"
 	"fmt"
 	htmltemplate "html/template"
-	"os"
-	"path/filepath"
 	"strings"
 	texttemplate "text/template"
 
+	root "github.com/vocdoni/saas-backend"
 	"github.com/vocdoni/saas-backend/notifications"
 )
 
-// AvailableTemplates is a map that stores the filename and the absolute path
+// availableTemplates is a map that stores the filename and the absolute path
 // of the email templates. The filename is the key and the path is the value.
-var AvailableTemplates map[TemplateFile]string
+var availableTemplates map[TemplateFile]string
 
 // TemplateFile represents an email template key. Every email template should
 // have a key that identifies it, which is the filename without the extension.
@@ -31,34 +30,34 @@ type MailTemplate struct {
 	WebAppURI   string
 }
 
-// Load function reads the email templates from the specified directory.
-// Returns a map with the filename and file absolute path. The filename is
-// the key and the path is the value.
-func Load(path string) error {
-	// create a map to store the filename and file content
-	htmlFiles := make(map[TemplateFile]string)
+// Available function returns the available email templates. It returns a map
+// with the filename and the absolute path of the email templates. The filename
+// is the key and the path is the value.
+func Available() map[TemplateFile]string {
+	return availableTemplates
+}
+
+// Load function reads the email templates from embedded assets. It reads the
+// html files from the "assets" directory and stores the filename and the file
+// path in the availableTemplates map. It returns an error if the directory
+// could not be read or if the files could not be read.
+func Load() error {
+	// reset the map to store the filename and file paths
+	availableTemplates = make(map[TemplateFile]string)
+	// read files from embedded assets
+	entries, err := root.Assets.ReadDir("assets")
+	if err != nil {
+		return err
+	}
 	// walk through the directory and read each file
-	if err := filepath.Walk(path, func(fPath string, info os.FileInfo, err error) error {
-		if err != nil {
-			return err
-		}
+	for _, entry := range entries {
 		// only process regular files and files with a ".html" extension
-		if !info.IsDir() && strings.HasSuffix(info.Name(), ".html") {
-			// get the absolute path of the file
-			absPath, err := filepath.Abs(fPath)
-			if err != nil {
-				return err
-			}
-			// remove the ".html" extension from the filename
-			filename := strings.TrimSuffix(info.Name(), ".html")
-			// store the filename and content in the map
-			htmlFiles[TemplateFile(filename)] = absPath
+		if !entry.IsDir() && strings.HasSuffix(entry.Name(), ".html") {
+			// store the filename and the path in the map
+			name := strings.TrimSuffix(entry.Name(), ".html")
+			availableTemplates[TemplateFile(name)] = "assets/" + entry.Name()
 		}
-		return nil
-	}); err != nil {
-		return err
 	}
-	AvailableTemplates = htmlFiles
 	return nil
 }
 
@@ -69,7 +68,7 @@ func Load(path string) error {
 // data provided. It returns the notification with the body and plain body
 // filled with the data provided.
 func (mt MailTemplate) ExecTemplate(data any) (*notifications.Notification, error) {
-	path, ok := AvailableTemplates[mt.File]
+	path, ok := availableTemplates[mt.File]
 	if !ok {
 		return nil, fmt.Errorf("template not found")
 	}
@@ -81,7 +80,11 @@ func (mt MailTemplate) ExecTemplate(data any) (*notifications.Notification, erro
 	// set the mail subject
 	n.Subject = mt.Placeholder.Subject
 	// parse the html template file
-	tmpl, err := htmltemplate.ParseFiles(path)
+	content, err := root.Assets.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	tmpl, err := htmltemplate.New(string(mt.File)).Parse(string(content))
 	if err != nil {
 		return nil, err
 	}