fix(@angular-devkit/build-angular): add NG_BUILD_MAX_WORKERS settimgs to control maximum number of workers

Author: alan-agius4

packages/angular_devkit/build_angular/src/utils/action-executor.ts

@@ -11,9 +11,9 @@ import * as os from 'os';
 import * as path from 'path';
 import { serialize } from 'v8';
 import { BundleActionCache } from './action-cache';
+import { maxWorkers } from './environment-options';
 import { I18nOptions } from './i18n-options';
 import { InlineOptions, ProcessBundleOptions, ProcessBundleResult } from './process-bundle';
-import { maxWorkers } from './workers';
 
 let workerFile = require.resolve('./process-bundle');
 workerFile =
@@ -35,7 +35,7 @@ export class BundleActionExecutor {
   }
 
   private static executeMethod<O>(worker: JestWorker, method: string, input: unknown): Promise<O> {
-    return ((worker as unknown) as Record<string, (i: unknown) => Promise<O>>)[method](input);
+    return (worker as unknown as Record<string, (i: unknown) => Promise<O>>)[method](input);
   }
 
   private ensureLarge(): JestWorker {

packages/angular_devkit/build_angular/src/utils/environment-options.ts

@@ -83,3 +83,15 @@ export const cachingBasePath = (() => {
 // Build profiling
 const profilingVariable = process.env['NG_BUILD_PROFILING'];
 export const profilingEnabled = isPresent(profilingVariable) && isEnabled(profilingVariable);
+
+/**
+ * Some environments, like CircleCI which use Docker report a number of CPUs by the host and not the count of available.
+ * This cause `Error: Call retries were exceeded` errors when trying to use them.
+ *
+ * @see https://github.com/nodejs/node/issues/28762
+ * @see https://github.com/webpack-contrib/terser-webpack-plugin/issues/143
+ * @see https://ithub.com/angular/angular-cli/issues/16860#issuecomment-588828079
+ *
+ */
+const maxWorkersVariable = process.env['NG_BUILD_MAX_WORKERS'];
+export const maxWorkers = isPresent(maxWorkersVariable) ? +maxWorkersVariable : 4;

packages/angular_devkit/build_angular/src/utils/index.ts

@@ -16,4 +16,3 @@ export * from './normalize-source-maps';
 export * from './normalize-optimization';
 export * from './normalize-builder-schema';
 export * from './url';
-export * from './workers';

packages/angular_devkit/build_angular/src/utils/workers.ts

@@ -23,13 +23,14 @@ import {
   debug,
 } from 'webpack';
 import { AssetPatternClass } from '../../browser/schema';
-import { BuildBrowserFeatures, maxWorkers } from '../../utils';
+import { BuildBrowserFeatures } from '../../utils';
 import { WebpackConfigOptions } from '../../utils/build-options';
 import { findCachePath } from '../../utils/cache-path';
 import {
   allowMangle,
   allowMinify,
   cachingDisabled,
+  maxWorkers,
   profilingEnabled,
   shouldBeautify,
 } from '../../utils/environment-options';