Add a configuration to disable signing up

internal/routes/usersignup.go

@@ -1,6 +1,9 @@
 package routes
 
 import (
+	"errors"
+	"net/http"
+
 	"git.artlef.fr/PersonalLibraryManager/internal/appcontext"
 	"git.artlef.fr/PersonalLibraryManager/internal/dto"
 	"git.artlef.fr/PersonalLibraryManager/internal/model"
@@ -9,6 +12,14 @@ import (
 )
 
 func PostSignupHandler(ac appcontext.AppContext) {
+	if ac.Config.DisableRegistration {
+		myvalidator.ReturnErrorsAsJsonResponse(&ac,
+			myvalidator.HttpError{
+				StatusCode: http.StatusForbidden,
+				Err:        errors.New("Registration has been disabled on this instance."),
+			})
+		return
+	}
 	var user dto.UserSignup
 	err := ac.C.ShouldBindJSON(&user)
 	if err != nil {