fix: Loading custom modules (#6411)

What:
   fix custom modules loading in medusa project
   pass medusa logger reference to MedusaApp

packages/modules-sdk/src/medusa-module.ts

@@ -18,6 +18,7 @@ import {
   simpleHash,
   stringifyCircular,
 } from "@medusajs/utils"
+import { EOL } from "os"
 import {
   moduleLoader,
   registerMedusaLinkModule,
@@ -312,6 +313,14 @@ export class MedusaModule {
           keyName
         ].__joinerConfig()
 
+        if (!joinerConfig.primaryKeys) {
+          logger.warn(
+            `Primary keys are not defined by the module ${keyName}. Setting default primary key to 'id'${EOL}`
+          )
+
+          joinerConfig.primaryKeys = ["id"]
+        }
+
         services[keyName].__joinerConfig = joinerConfig
         MedusaModule.setJoinerConfig(keyName, joinerConfig)
       }