feat(parameters): AppConfigProvider (#1200)

packages/parameters/package.json

@@ -54,9 +54,12 @@
     "nodejs"
   ],
   "devDependencies": {
+    "@aws-sdk/client-appconfigdata": "^3.241.0",
     "@aws-sdk/client-secrets-manager": "^3.238.0",
     "@aws-sdk/client-ssm": "^3.244.0",
+    "@aws-sdk/types": "^3.226.0",
     "aws-sdk-client-mock": "^2.0.1",
     "aws-sdk-client-mock-jest": "^2.0.1"
   }
 }
+

packages/parameters/src/appconfig/AppConfigProvider.ts

@@ -0,0 +1,127 @@
+import { BaseProvider, DEFAULT_PROVIDERS } from '../BaseProvider';
+import {
+  AppConfigDataClient,
+  StartConfigurationSessionCommand,
+  GetLatestConfigurationCommand,
+} from '@aws-sdk/client-appconfigdata';
+import type { StartConfigurationSessionCommandInput } from '@aws-sdk/client-appconfigdata';
+import type {
+  AppConfigProviderOptions,
+  AppConfigGetOptionsInterface,
+} from '../types/AppConfigProvider';
+
+class AppConfigProvider extends BaseProvider {
+  public client: AppConfigDataClient;
+  protected configurationTokenStore: Map<string, string> = new Map();
+  private application?: string;
+  private environment: string;
+
+  /**
+   * It initializes the AppConfigProvider class'.
+   * *
+   * @param {AppConfigProviderOptions} options
+   */
+  public constructor(options: AppConfigProviderOptions) {
+    super();
+    this.client = new AppConfigDataClient(options.clientConfig || {});
+    if (!options?.application && !process.env['POWERTOOLS_SERVICE_NAME']) {
+      throw new Error(
+        'Application name is not defined or POWERTOOLS_SERVICE_NAME is not set'
+      );
+    }
+    this.application =
+      options.application || process.env['POWERTOOLS_SERVICE_NAME'];
+    this.environment = options.environment;
+  }
+
+  /**
+   * Retrieve a configuration from AWS App config.
+   */
+  public async get(
+    name: string,
+    options?: AppConfigGetOptionsInterface
+  ): Promise<undefined | string | Uint8Array | Record<string, unknown>> {
+    return super.get(name, options);
+  }
+
+  /**
+   * Retrieving multiple configurations is not supported by AWS App Config Provider.
+   */
+  public async getMultiple(
+    path: string,
+    _options?: unknown
+  ): Promise<undefined | Record<string, unknown>> {
+    return super.getMultiple(path);
+  }
+
+  /**
+   * Retrieve a configuration from AWS App config.
+   *
+   * @param {string} name - Name of the configuration
+   * @param {AppConfigGetOptionsInterface} options - SDK options to propagate to `StartConfigurationSession` API call
+   * @returns {Promise<Uint8Array | undefined>}
+   */
+  protected async _get(
+    name: string,
+    options?: AppConfigGetOptionsInterface
+  ): Promise<Uint8Array | undefined> {
+
+    /**
+     * The new AppConfig APIs require two API calls to return the configuration
+     * First we start the session and after that we retrieve the configuration
+     * We need to store { name: token } pairs to use in the next execution
+     **/
+
+    if (!this.configurationTokenStore.has(name)) {
+
+      const sessionOptions: StartConfigurationSessionCommandInput = {
+        ...(options?.sdkOptions || {}),
+        ApplicationIdentifier: this.application,
+        ConfigurationProfileIdentifier: name,
+        EnvironmentIdentifier: this.environment,
+      };
+
+      const sessionCommand = new StartConfigurationSessionCommand(
+        sessionOptions
+      );
+
+      const session = await this.client.send(sessionCommand);
+
+      if (!session.InitialConfigurationToken) throw new Error('Unable to retrieve the configuration token');
+
+      this.configurationTokenStore.set(name, session.InitialConfigurationToken);
+    }
+
+    const getConfigurationCommand = new GetLatestConfigurationCommand({
+      ConfigurationToken: this.configurationTokenStore.get(name),
+    });
+
+    const response = await this.client.send(getConfigurationCommand);
+
+    if (response.NextPollConfigurationToken) {
+      this.configurationTokenStore.set(name, response.NextPollConfigurationToken);
+    } else {
+      this.configurationTokenStore.delete(name);
+    }
+
+    return response.Configuration;
+  }
+
+  /**
+   * Retrieving multiple configurations is not supported by AWS App Config Provider API.
+   *
+   * @throws Not Implemented Error.
+   */
+  protected async _getMultiple(
+    _path: string,
+    _sdkOptions?: unknown
+  ): Promise<Record<string, string | undefined>> {
+    return this._notImplementedError();
+  }
+
+  private _notImplementedError(): never {
+    throw new Error('Not Implemented');
+  }
+}
+
+export { AppConfigProvider, DEFAULT_PROVIDERS };

packages/parameters/src/appconfig/getAppConfig.ts

@@ -0,0 +1,22 @@
+import { AppConfigProvider, DEFAULT_PROVIDERS } from './AppConfigProvider';
+import type { GetAppConfigCombinedInterface } from '../types/AppConfigProvider';
+
+/**
+ * Gets the AppConfig data for the specified name.
+ *
+ * @param {string} name - The configuration profile ID or the configuration profile name.
+ * @param {GetAppConfigCombinedInterface} options - Options for the AppConfigProvider and the get method.
+ * @returns {Promise<undefined | string | Uint8Array | Record<string, unknown>>} A promise that resolves to the AppConfig data or undefined if not found.
+ */
+const getAppConfig = (
+  name: string,
+  options: GetAppConfigCombinedInterface
+): Promise<undefined | string | Uint8Array | Record<string, unknown>> => {
+  if (!DEFAULT_PROVIDERS.hasOwnProperty('appconfig')) {
+    DEFAULT_PROVIDERS.appconfig = new AppConfigProvider(options);
+  }
+
+  return DEFAULT_PROVIDERS.appconfig.get(name, options);
+};
+
+export { getAppConfig };

packages/parameters/src/appconfig/index.ts

@@ -0,0 +1,2 @@
+export * from './AppConfigProvider';
+export * from './getAppConfig';

packages/parameters/src/types/AppConfigProvider.ts

@@ -0,0 +1,50 @@
+import type {
+  AppConfigDataClientConfig,
+  StartConfigurationSessionCommandInput,
+} from '@aws-sdk/client-appconfigdata';
+import type { GetOptionsInterface } from 'types/BaseProvider';
+
+/**
+ * Options for the AppConfigProvider class constructor.
+ *
+ *  @interface AppConfigProviderOptions
+ *  @property {string} environment - The environment ID or the environment name.
+ *  @property {string} [application] - The application ID or the application name.
+ *  @property {AppConfigDataClientConfig} [clientConfig] - Optional configuration to pass during client initialization, e.g. AWS region.
+ */
+interface AppConfigProviderOptions {
+  environment: string
+  application?: string
+  clientConfig?: AppConfigDataClientConfig
+}
+
+/**
+ * Options for the AppConfigProvider get method.
+ *
+ * @interface AppConfigGetOptionsInterface
+ * @extends {GetOptionsInterface}
+ * @property {StartConfigurationSessionCommandInput} [sdkOptions] - Required options to start configuration session.
+ */
+interface AppConfigGetOptionsInterface extends Omit<GetOptionsInterface, 'sdkOptions'> {
+  sdkOptions?: Omit<
+  Partial<StartConfigurationSessionCommandInput>,
+  | 'ApplicationIdentifier'
+  | 'EnvironmentIdentifier | ConfigurationProfileIdentifier'
+  >
+}
+
+/**
+ * Combined options for the getAppConfig utility function.
+ *
+ * @interface getAppConfigCombinedInterface
+ * @extends {AppConfigProviderOptions, AppConfigGetOptionsInterface}
+ */
+interface GetAppConfigCombinedInterface
+  extends Omit<AppConfigProviderOptions, 'clientConfig'>,
+  AppConfigGetOptionsInterface {}
+
+export {
+  AppConfigProviderOptions,
+  AppConfigGetOptionsInterface,
+  GetAppConfigCombinedInterface,
+};

packages/parameters/tests/unit/AppConfigProvider.test.ts

@@ -0,0 +1,167 @@
+/**
+ * Test AppConfigProvider class
+ *
+ * @group unit/parameters/AppConfigProvider/class
+ */
+import { AppConfigProvider } from '../../src/appconfig/index';
+
+import {
+  AppConfigDataClient,
+  StartConfigurationSessionCommand,
+  GetLatestConfigurationCommand,
+} from '@aws-sdk/client-appconfigdata';
+import { mockClient } from 'aws-sdk-client-mock';
+import 'aws-sdk-client-mock-jest';
+import { AppConfigProviderOptions } from '../../src/types/AppConfigProvider';
+
+describe('Class: AppConfigProvider', () => {
+  const client = mockClient(AppConfigDataClient);
+  const encoder = new TextEncoder();
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  describe('Method: _get', () => {
+    test('when called with name and options, it returns binary configuration', async () => {
+      // Prepare
+      const options: AppConfigProviderOptions = {
+        application: 'MyApp',
+        environment: 'MyAppProdEnv',
+      };
+      const provider = new AppConfigProvider(options);
+      const name = 'MyAppFeatureFlag';
+
+      const fakeInitialToken = 'aW5pdGlhbFRva2Vu';
+      const fakeNextToken = 'bmV4dFRva2Vu';
+      const mockData = encoder.encode('myAppConfiguration');
+
+      client
+        .on(StartConfigurationSessionCommand)
+        .resolves({
+          InitialConfigurationToken: fakeInitialToken,
+        })
+        .on(GetLatestConfigurationCommand)
+        .resolves({
+          Configuration: mockData,
+          NextPollConfigurationToken: fakeNextToken,
+        });
+
+      // Act
+      const result = await provider.get(name);
+
+      // Assess
+      expect(result).toBe(mockData);
+    });
+
+    test('when called without application option, it will be retrieved from POWERTOOLS_SERVICE_NAME and provider successfully return configuration', async () => {
+      // Prepare
+      process.env.POWERTOOLS_SERVICE_NAME = 'MyApp';
+      const config = {
+        environment: 'MyAppProdEnv',
+      };
+      const provider = new AppConfigProvider(config);
+      const name = 'MyAppFeatureFlag';
+
+      const fakeInitialToken = 'aW5pdGlhbFRva2Vu';
+      const fakeNextToken = 'bmV4dFRva2Vu';
+      const mockData = encoder.encode('myAppConfiguration');
+
+      client
+        .on(StartConfigurationSessionCommand)
+        .resolves({
+          InitialConfigurationToken: fakeInitialToken,
+        })
+        .on(GetLatestConfigurationCommand)
+        .resolves({
+          Configuration: mockData,
+          NextPollConfigurationToken: fakeNextToken,
+        });
+
+      // Act
+      const result = await provider.get(name);
+
+      // Assess
+      expect(result).toBe(mockData);
+    });
+
+    test('when called without application option and POWERTOOLS_SERVICE_NAME is not set, it throws an Error', async () => {
+      // Prepare
+      process.env.POWERTOOLS_SERVICE_NAME = '';
+      const options = {
+        environment: 'MyAppProdEnv',
+      };
+
+      // Act & Assess
+      expect(() => {
+        new AppConfigProvider(options);
+      }).toThrow();
+    });
+
+    test('when configuration response doesn\'t have the next token it should force a new session by removing the stored token', async () => {
+      // Prepare
+      class AppConfigProviderMock extends AppConfigProvider {
+        public _addToStore(key: string, value: string): void {
+          this.configurationTokenStore.set(key, value);
+        }
+        public _storeHas(key: string): boolean {
+          return this.configurationTokenStore.has(key);
+        }
+      }
+
+      const options: AppConfigProviderOptions = {
+        application: 'MyApp',
+        environment: 'MyAppProdEnv',
+      };
+      const provider = new AppConfigProviderMock(options);
+      const name = 'MyAppFeatureFlag';
+      const fakeToken = 'ZmFrZVRva2Vu';
+      const mockData = encoder.encode('myAppConfiguration');
+
+      client.on(GetLatestConfigurationCommand).resolves({
+        Configuration: mockData,
+        NextPollConfigurationToken: undefined,
+      });
+
+      // Act
+      provider._addToStore(name, fakeToken);
+      await provider.get(name);
+
+      // Assess
+      expect(provider._storeHas(name)).toBe(false);
+    });
+
+    test('when session response doesn\'t have an initial token, it throws an error', async () => {
+      // Prepare
+      const options: AppConfigProviderOptions = {
+        application: 'MyApp',
+        environment: 'MyAppProdEnv',
+      };
+      const provider = new AppConfigProvider(options);
+      const name = 'MyAppFeatureFlag';
+
+      client.on(StartConfigurationSessionCommand).resolves({
+        InitialConfigurationToken: undefined,
+      });
+
+      // Act & Assess
+      await expect(provider.get(name)).rejects.toThrow();
+    });
+  });
+
+  describe('Method: _getMultiple', () => {
+    test('when called it throws an Error, because this method is not supported by AppConfig API', async () => {
+      // Prepare
+      const config = {
+        application: 'MyApp',
+        environment: 'MyAppProdEnv',
+      };
+      const path = '/my/path';
+      const provider = new AppConfigProvider(config);
+      const errorMessage = 'Not Implemented';
+
+      // Act & Assess
+      await expect(provider.getMultiple(path)).rejects.toThrow(errorMessage);
+    });
+  });
+});