feat(toolkit-lib): network detector

packages/@aws-cdk-testing/cli-integ/tests/cli-integ-tests/proxy/cdk-requests-go-through-a-proxy-when-configured.integtest.ts

@@ -14,6 +14,9 @@ integTest('requests go through a proxy when configured',
       // Delete notices cache if it exists
       await fs.rm(path.join(cdkCacheDir, 'notices.json'), { force: true });
 
+      // Delete connection cache if it exists
+      await fs.rm(path.join(cdkCacheDir, 'connection.json'), { force: true });
+
       await fixture.cdkDeploy('test-2', {
         captureStderr: true,
         options: [
@@ -26,7 +29,6 @@ integTest('requests go through a proxy when configured',
       });
 
       const requests = await proxyServer.getSeenRequests();
-
       expect(requests.map(req => req.url))
         .toContain('https://cli.cdk.dev-tools.aws.dev/notices.json');
 

packages/@aws-cdk/toolkit-lib/lib/api/index.ts

@@ -10,6 +10,7 @@ export * from './garbage-collection';
 export * from './hotswap';
 export * from './io';
 export * from './logs-monitor';
+export * from './network-detector';
 export * from './notices';
 export * from './plugin';
 export * from './refactoring';

packages/@aws-cdk/toolkit-lib/lib/api/network-detector/index.ts

@@ -0,0 +1 @@
+export * from './network-detector';

packages/@aws-cdk/toolkit-lib/lib/api/network-detector/network-detector.ts

@@ -0,0 +1,98 @@
+import * as https from 'node:https';
+import type { RequestOptions } from 'node:https';
+import * as path from 'path';
+import * as fs from 'fs-extra';
+import { cdkCacheDir } from '../../util';
+
+interface CachedConnectivity {
+  expiration: number;
+  hasConnectivity: boolean;
+}
+
+const TIME_TO_LIVE_SUCCESS = 60 * 60 * 1000; // 1 hour
+const CACHE_FILE_PATH = path.join(cdkCacheDir(), 'connection.json');
+
+/**
+ * Detects internet connectivity by making a lightweight request to the notices endpoint
+ */
+export class NetworkDetector {
+  /**
+   * Check if internet connectivity is available
+   */
+  public static async hasConnectivity(agent?: https.Agent): Promise<boolean> {
+    const cachedData = await this.load();
+    const expiration = cachedData.expiration ?? 0;
+
+    if (Date.now() > expiration) {
+      try {
+        const connected = await this.ping(agent);
+        const updatedData = {
+          expiration: Date.now() + TIME_TO_LIVE_SUCCESS,
+          hasConnectivity: connected,
+        };
+        await this.save(updatedData);
+        return connected;
+      } catch {
+        return false;
+      }
+    } else {
+      return cachedData.hasConnectivity;
+    }
+  }
+
+  // We are observing lots of timeouts when running in a massively parallel
+  // integration test environment, so wait for a longer timeout there.
+  //
+  // In production, have a short timeout to not hold up the user experience.
+  private static readonly TIMEOUT = process.env.TESTING_CDK ? 30_000 : 3_000;
+  private static readonly URL = 'https://cli.cdk.dev-tools.aws.dev/notices.json';
+
+  private static async load(): Promise<CachedConnectivity> {
+    const defaultValue = {
+      expiration: 0,
+      hasConnectivity: false,
+    };
+
+    try {
+      return fs.existsSync(CACHE_FILE_PATH)
+        ? await fs.readJSON(CACHE_FILE_PATH) as CachedConnectivity
+        : defaultValue;
+    } catch {
+      return defaultValue;
+    }
+  }
+
+  private static async save(cached: CachedConnectivity): Promise<void> {
+    try {
+      await fs.ensureFile(CACHE_FILE_PATH);
+      await fs.writeJSON(CACHE_FILE_PATH, cached);
+    } catch {
+      // Silently ignore cache save errors
+    }
+  }
+
+  private static ping(agent?: https.Agent): Promise<boolean> {
+    const options: RequestOptions = {
+      method: 'HEAD',
+      agent: agent,
+      timeout: this.TIMEOUT,
+    };
+
+    return new Promise((resolve) => {
+      const req = https.request(
+        NetworkDetector.URL,
+        options,
+        (res) => {
+          resolve(res.statusCode !== undefined && res.statusCode < 500);
+        },
+      );
+      req.on('error', () => resolve(false));
+      req.on('timeout', () => {
+        req.destroy();
+        resolve(false);
+      });
+
+      req.end();
+    });
+  }
+}

packages/@aws-cdk/toolkit-lib/lib/api/notices/web-data-source.ts

@@ -5,6 +5,7 @@ import type { Notice, NoticeDataSource } from './types';
 import { ToolkitError } from '../../toolkit/toolkit-error';
 import { formatErrorMessage, humanHttpStatusError, humanNetworkError } from '../../util';
 import type { IoHelper } from '../io/private';
+import { NetworkDetector } from '../network-detector/network-detector';
 
 /**
  * A data source that fetches notices from the CDK notices data source
@@ -20,6 +21,7 @@ export class WebsiteNoticeDataSourceProps {
    * @default - Official CDK notices
    */
   readonly url?: string | URL;
+
   /**
    * The agent responsible for making the network requests.
    *
@@ -44,6 +46,12 @@ export class WebsiteNoticeDataSource implements NoticeDataSource {
   }
 
   async fetch(): Promise<Notice[]> {
+    // Check connectivity before attempting network request
+    const hasConnectivity = await NetworkDetector.hasConnectivity(this.agent);
+    if (!hasConnectivity) {
+      throw new ToolkitError('No internet connectivity detected');
+    }
+
     // We are observing lots of timeouts when running in a massively parallel
     // integration test environment, so wait for a longer timeout there.
     //
@@ -66,7 +74,8 @@ export class WebsiteNoticeDataSource implements NoticeDataSource {
       timer.unref();
 
       try {
-        req = https.get(this.url,
+        req = https.get(
+          this.url,
           options,
           res => {
             if (res.statusCode === 200) {
@@ -92,7 +101,8 @@ export class WebsiteNoticeDataSource implements NoticeDataSource {
             } else {
               reject(new ToolkitError(`${humanHttpStatusError(res.statusCode!)} (Status code: ${res.statusCode})`));
             }
-          });
+          },
+        );
         req.on('error', e => {
           reject(ToolkitError.withCause(humanNetworkError(e), e));
         });

packages/@aws-cdk/toolkit-lib/test/api/notices.test.ts

@@ -5,6 +5,7 @@ import * as fs from 'fs-extra';
 import * as nock from 'nock';
 import { Context } from '../../lib/api/context';
 import { asIoHelper } from '../../lib/api/io/private';
+import { NetworkDetector } from '../../lib/api/network-detector/network-detector';
 import { Notices } from '../../lib/api/notices';
 import { CachedDataSource } from '../../lib/api/notices/cached-data-source';
 import { FilteredNotice, NoticesFilter } from '../../lib/api/notices/filter';
@@ -540,6 +541,24 @@ function parseTestComponent(x: string): Component {
 describe(WebsiteNoticeDataSource, () => {
   const dataSource = new WebsiteNoticeDataSource(ioHelper);
 
+  beforeEach(() => {
+    // Mock NetworkDetector to return true by default for existing tests
+    jest.spyOn(NetworkDetector, 'hasConnectivity').mockResolvedValue(true);
+  });
+
+  afterEach(() => {
+    jest.restoreAllMocks();
+  });
+
+  test('throws error when no connectivity detected', async () => {
+    const mockHasConnectivity = jest.spyOn(NetworkDetector, 'hasConnectivity').mockResolvedValue(false);
+
+    await expect(dataSource.fetch()).rejects.toThrow('No internet connectivity detected');
+    expect(mockHasConnectivity).toHaveBeenCalledWith(undefined);
+
+    mockHasConnectivity.mockRestore();
+  });
+
   test('returns data when download succeeds', async () => {
     const result = await mockCall(200, {
       notices: [BASIC_NOTICE, MULTIPLE_AFFECTED_VERSIONS_NOTICE],

packages/@aws-cdk/toolkit-lib/test/util/network-detector.test.ts

@@ -0,0 +1,169 @@
+import * as https from 'node:https';
+import * as fs from 'fs-extra';
+import { NetworkDetector } from '../../lib/api/network-detector/network-detector';
+
+// Mock the https module
+jest.mock('node:https');
+const mockHttps = https as jest.Mocked<typeof https>;
+
+// Mock fs-extra
+jest.mock('fs-extra');
+const mockFs = fs as jest.Mocked<typeof fs>;
+
+// Mock cdkCacheDir
+jest.mock('../../lib/util', () => ({
+  cdkCacheDir: jest.fn(() => '/mock/cache/dir'),
+}));
+
+describe('NetworkDetector', () => {
+  let mockRequest: jest.Mock;
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+    mockRequest = jest.fn();
+    mockHttps.request.mockImplementation(mockRequest);
+  });
+
+  test('returns true when server responds with success status', async () => {
+    const mockReq = {
+      on: jest.fn(),
+      end: jest.fn(),
+      destroy: jest.fn(),
+    };
+
+    mockRequest.mockImplementation((_url, _options, callback) => {
+      setTimeout(() => callback({ statusCode: 200 }), 0);
+      return mockReq;
+    });
+
+    mockFs.existsSync.mockReturnValue(false);
+    (mockFs.ensureFile as jest.Mock).mockResolvedValue(undefined);
+    (mockFs.writeJSON as jest.Mock).mockResolvedValue(undefined);
+
+    const result = await NetworkDetector.hasConnectivity();
+    expect(result).toBe(true); // Should return true for successful HTTP response
+  });
+
+  test('returns false when server responds with server error', async () => {
+    const mockReq = {
+      on: jest.fn(),
+      end: jest.fn(),
+      destroy: jest.fn(),
+    };
+
+    mockRequest.mockImplementation((_url, _options, callback) => {
+      setTimeout(() => callback({ statusCode: 500 }), 0);
+      return mockReq;
+    });
+
+    mockFs.existsSync.mockReturnValue(false);
+    (mockFs.ensureFile as jest.Mock).mockResolvedValue(undefined);
+    (mockFs.writeJSON as jest.Mock).mockResolvedValue(undefined);
+
+    const result = await NetworkDetector.hasConnectivity();
+    expect(result).toBe(false); // Should return false for server error status codes
+  });
+
+  test('returns false on network error', async () => {
+    const mockReq = {
+      on: jest.fn((event, handler) => {
+        if (event === 'error') {
+          setTimeout(() => handler(new Error('Network error')), 0);
+        }
+      }),
+      end: jest.fn(),
+      destroy: jest.fn(),
+    };
+
+    mockRequest.mockReturnValue(mockReq);
+    mockFs.existsSync.mockReturnValue(false);
+
+    const result = await NetworkDetector.hasConnectivity();
+    expect(result).toBe(false); // Should return false when network request fails
+  });
+
+  test('returns cached result from disk when not expired', async () => {
+    const cachedData = {
+      expiration: Date.now() + 30000, // 30 seconds in future
+      hasConnectivity: true,
+    };
+
+    mockFs.existsSync.mockReturnValue(true);
+    (mockFs.readJSON as jest.Mock).mockResolvedValue(cachedData);
+
+    const result = await NetworkDetector.hasConnectivity();
+
+    expect(result).toBe(true); // Should return cached connectivity result
+    expect(mockRequest).not.toHaveBeenCalled(); // Should not make network request when cache is valid
+  });
+
+  test('performs ping when disk cache is expired', async () => {
+    const expiredData = {
+      expiration: Date.now() - 1000, // 1 second ago
+      hasConnectivity: true,
+    };
+
+    const mockReq = {
+      on: jest.fn(),
+      end: jest.fn(),
+      destroy: jest.fn(),
+    };
+
+    mockRequest.mockImplementation((_url, _options, callback) => {
+      setTimeout(() => callback({ statusCode: 200 }), 0);
+      return mockReq;
+    });
+
+    mockFs.existsSync.mockReturnValue(true);
+    (mockFs.readJSON as jest.Mock).mockResolvedValue(expiredData);
+    (mockFs.ensureFile as jest.Mock).mockResolvedValue(undefined);
+    (mockFs.writeJSON as jest.Mock).mockResolvedValue(undefined);
+
+    const result = await NetworkDetector.hasConnectivity();
+
+    expect(result).toBe(true); // Should return fresh connectivity result
+    expect(mockRequest).toHaveBeenCalledTimes(1); // Should make network request when cache is expired
+  });
+
+  test('handles cache save errors gracefully', async () => {
+    const mockReq = {
+      on: jest.fn(),
+      end: jest.fn(),
+      destroy: jest.fn(),
+    };
+
+    mockRequest.mockImplementation((_url, _options, callback) => {
+      setTimeout(() => callback({ statusCode: 200 }), 0);
+      return mockReq;
+    });
+
+    mockFs.existsSync.mockReturnValue(false);
+    (mockFs.ensureFile as jest.Mock).mockRejectedValue(new Error('Disk full'));
+
+    const result = await NetworkDetector.hasConnectivity();
+
+    expect(result).toBe(true); // Should still return connectivity result despite cache save failure
+  });
+
+  test('handles cache load errors gracefully', async () => {
+    const mockReq = {
+      on: jest.fn(),
+      end: jest.fn(),
+      destroy: jest.fn(),
+    };
+
+    mockRequest.mockImplementation((_url, _options, callback) => {
+      setTimeout(() => callback({ statusCode: 200 }), 0);
+      return mockReq;
+    });
+
+    mockFs.existsSync.mockReturnValue(true);
+    (mockFs.readJSON as jest.Mock).mockRejectedValue(new Error('Read failed'));
+    (mockFs.ensureFile as jest.Mock).mockResolvedValue(undefined);
+    (mockFs.writeJSON as jest.Mock).mockResolvedValue(undefined);
+
+    const result = await NetworkDetector.hasConnectivity();
+
+    expect(result).toBe(true); // Should still return connectivity result despite cache load failure
+  });
+});

packages/aws-cdk/lib/api/network-detector.ts

@@ -0,0 +1,2 @@
+/* eslint-disable import/no-relative-packages */
+export * from '../../../@aws-cdk/toolkit-lib/lib/api/network-detector';