feat: disable user signup

server/handlers/oauth_callback.go

@@ -71,6 +71,10 @@ func OAuthCallbackHandler() gin.HandlerFunc {
 		existingUser, err := db.Provider.GetUserByEmail(user.Email)
 
 		if err != nil {
+			if envstore.EnvStoreObj.GetBoolStoreEnvVariable(constants.EnvKeyDisableSignUp) {
+				c.JSON(400, gin.H{"error": "signup is disabled for this instance"})
+				return
+			}
 			// user not registered, register user and generate session token
 			user.SignupMethods = provider
 			// make sure inputRoles don't include protected roles