scaffolder-backend: make concurrentTasksLimit configurable via static config

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

.changeset/metal-eagles-invite.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-scaffolder-backend': patch
+---
+
+The `concurrentTasksLimit` option can now be configured via static configuration as well. Setting it to 0 will now also disable the task worker.

plugins/scaffolder-backend/config.d.ts

@@ -28,5 +28,14 @@ export interface Config {
      * The commit message used when new components are created.
      */
     defaultCommitMessage?: string;
+
+    /**
+     * Sets the number of concurrent tasks that can be run at any given time on the TaskWorker.
+     *
+     * Defaults to 10.
+     *
+     * Set to 0 to disable task workers altogether.
+     */
+    concurrentTasksLimit?: number;
   };
 }

plugins/scaffolder-backend/src/service/router.ts

@@ -231,13 +231,15 @@ export async function createRouter(
     catalogClient,
     actions,
     taskWorkers,
-    concurrentTasksLimit,
     scheduler,
     additionalTemplateFilters,
     additionalTemplateGlobals,
     permissions,
     permissionRules,
   } = options;
+  const concurrentTasksLimit =
+    options.concurrentTasksLimit ??
+    options.config.getOptionalNumber('scaffolder.concurrentTasksLimit');
 
   const logger = parentLogger.child({ plugin: 'scaffolder' });
 
@@ -275,19 +277,21 @@ export async function createRouter(
   const actionRegistry = new TemplateActionRegistry();
 
   const workers = [];
-  for (let i = 0; i < (taskWorkers || 1); i++) {
-    const worker = await TaskWorker.create({
-      taskBroker,
-      actionRegistry,
-      integrations,
-      logger,
-      workingDirectory,
-      additionalTemplateFilters,
-      additionalTemplateGlobals,
-      concurrentTasksLimit,
-      permissions,
-    });
-    workers.push(worker);
+  if (concurrentTasksLimit !== 0) {
+    for (let i = 0; i < (taskWorkers || 1); i++) {
+      const worker = await TaskWorker.create({
+        taskBroker,
+        actionRegistry,
+        integrations,
+        logger,
+        workingDirectory,
+        additionalTemplateFilters,
+        additionalTemplateGlobals,
+        concurrentTasksLimit,
+        permissions,
+      });
+      workers.push(worker);
+    }
   }
 
   const actionsToRegister = Array.isArray(actions)