feat: v2 - add worker mode (#6739)

**What**
- Adds support for starting a Medusa process with a worker mode.
- The worker modes supported are "shared", "worker", "server"
- In "worker" mode, API routes are not registered and modules that need to run workers (e.g., event bus redis) can use the flag to conditionally start workers.
- In "server" mode, API routes are registered and workers are not started.
- In "shared" mode, API routes are registered and workers are started. This is great for development.

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

@@ -71,7 +71,8 @@ export async function loadModules(
   modulesConfig,
   sharedContainer,
   migrationOnly = false,
-  loaderOnly = false
+  loaderOnly = false,
+  workerMode: "shared" | "worker" | "server" = "server"
 ) {
   const allModules = {}
 
@@ -113,6 +114,7 @@ export async function loadModules(
         moduleExports,
         migrationOnly,
         loaderOnly,
+        workerMode,
       })) as LoadedModule
 
       if (loaderOnly) {
@@ -202,6 +204,7 @@ export type MedusaAppOutput = {
 }
 
 export type MedusaAppOptions = {
+  workerMode?: "shared" | "worker" | "server"
   sharedContainer?: MedusaContainer
   sharedResourcesConfig?: SharedResources
   loadedModules?: LoadedModule[]
@@ -232,6 +235,7 @@ async function MedusaApp_({
   onApplicationStartCb,
   migrationOnly = false,
   loaderOnly = false,
+  workerMode = "server",
 }: MedusaAppOptions & { migrationOnly?: boolean } = {}): Promise<{
   modules: Record<string, LoadedModule | LoadedModule[]>
   link: RemoteLink | undefined
@@ -300,7 +304,8 @@ async function MedusaApp_({
     modules,
     sharedContainer_,
     migrationOnly,
-    loaderOnly
+    loaderOnly,
+    workerMode
   )
 
   if (loaderOnly) {

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

@@ -69,6 +69,7 @@ export type ModuleBootstrapOptions = {
    * Forces the modules bootstrapper to only run the modules loaders and return prematurely
    */
   loaderOnly?: boolean
+  workerMode?: "shared" | "worker" | "server"
 }
 
 export type LinkModuleBootstrapOptions = {
@@ -225,6 +226,7 @@ export class MedusaModule {
     injectedDependencies,
     migrationOnly,
     loaderOnly,
+    workerMode,
   }: ModuleBootstrapOptions): Promise<{
     [key: string]: T
   }> {
@@ -267,6 +269,7 @@ export class MedusaModule {
         options: declaration?.options ?? declaration,
         alias: declaration?.alias,
         main: declaration?.main,
+        worker_mode: workerMode,
       }
     }
 
@@ -302,7 +305,7 @@ export class MedusaModule {
         moduleResolutions,
         logger: logger_,
         migrationOnly,
-        loaderOnly
+        loaderOnly,
       })
     } catch (err) {
       errorLoading(err)