Add node region providers

Author: jeskew

packages/region-provider-node/.gitignore

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+/node_modules/
+*.js
+*.js.map
+*.d.ts

packages/region-provider-node/__tests__/fromEnv.ts

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+import {fromEnv, ENV_REGION} from '../lib/fromEnv';
+
+describe('fromEnv', () => {
+    const ENV_CUSTOM = 'AWS_DEFAULT_REGION';
+    const envRegion = process.env[ENV_REGION];
+    const customEnv = process.env[ENV_CUSTOM];
+
+    beforeEach(() => {
+        delete process.env[ENV_REGION];
+        delete process.env[ENV_CUSTOM];
+    });
+
+    afterAll(() => {
+        process.env[ENV_CUSTOM] = customEnv;
+        process.env[ENV_REGION] = envRegion;
+    });
+
+    it(`should read from the ${ENV_REGION} environment variable`, async () => {
+        process.env[ENV_REGION] = 'us-north-12';
+        expect(await fromEnv()()).toBe(process.env[ENV_REGION]);
+    });
+
+    it(`should reject the promise is ${ENV_REGION} is not set`, async () => {
+        await expect(fromEnv()()).rejects;
+    });
+
+    it('should allow specifying custom environment variables', async () => {
+        process.env[ENV_CUSTOM] = 'eu-central-35';
+        expect(process.env[ENV_REGION]).toBeUndefined();
+        expect(await fromEnv(ENV_CUSTOM)()).toBe(process.env[ENV_CUSTOM]);
+    });
+});

packages/region-provider-node/__tests__/fromSharedConfigFiles.ts

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+export * from './lib/fromEnv';
+export * from './lib/fromSharedConfigFiles';

packages/region-provider-node/index.ts

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+import {Provider} from '@aws/types';
+
+export const ENV_REGION = 'AWS_REGION';
+
+export function fromEnv(variableName: string = ENV_REGION): Provider<string> {
+    return () => {
+        const envRegion = process.env[variableName];
+        if (envRegion) {
+            return Promise.resolve(envRegion);
+        }
+
+        return Promise.reject(
+            `No value defined for the ${variableName} environment variable`
+        );
+    };
+}

packages/region-provider-node/lib/fromEnv.ts

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+import {
+    loadSharedConfigFiles,
+    SharedConfigFiles,
+    SharedConfigInit as BaseSharedConfigInit,
+} from '@aws/shared-ini-file-loader';
+import {Provider} from '@aws/types';
+
+const DEFAULT_PROFILE = 'default';
+export const ENV_PROFILE = 'AWS_PROFILE';
+
+export interface SharedConfigInit extends BaseSharedConfigInit {
+    /**
+     * The configuration profile to use.
+     */
+    profile?: string;
+
+    /**
+     * A promise that will be resolved with loaded and parsed credentials files.
+     * Used to avoid loading shared config files multiple times.
+     */
+    loadedConfig?: Promise<SharedConfigFiles>;
+}
+
+export function fromSharedConfigFiles(
+    init: SharedConfigInit = {}
+): Provider<string> {
+    return () => {
+        const {
+            loadedConfig = loadSharedConfigFiles(init),
+            profile = process.env[ENV_PROFILE] || DEFAULT_PROFILE
+        } = init;
+
+        return loadedConfig.then(({configFile, credentialsFile}) => {
+            for (let file of [credentialsFile, configFile]) {
+                const {region} = file[profile] || <any>{};
+                if (typeof region === 'string') {
+                    return region;
+                }
+            }
+
+            throw new Error(
+                `No region found for profile ${profile} in SDK configuration files`
+            );
+        });
+    }
+}

packages/region-provider-node/lib/fromSharedConfigFiles.ts

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+{
+  "name": "@aws/region-provider-node",
+  "version": "0.0.1",
+  "private": true,
+  "description": "AWS region provider for Node.JS. Will determine the default region to use for AWS clients by checking known environment variables and the EC2 instance metadata service",
+  "main": "index.js",
+  "scripts": {
+    "prepublishOnly": "tsc",
+    "pretest": "tsc",
+    "test": "jest"
+  },
+  "keywords": [
+    "aws",
+    "credentials"
+  ],
+  "author": "[email protected]",
+  "license": "Apache-2.0",
+  "dependencies": {
+    "@aws/region-provider": "^0.0.1",
+    "@aws/shared-ini-file-loader": "^0.0.1",
+    "@aws/types": "^0.0.1"
+  },
+  "devDependencies": {
+    "@types/jest": "^20.0.2",
+    "jest": "^20.0.4",
+    "typescript": "^2.3"
+  }
+}

packages/region-provider-node/package.json

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+{
+  "compilerOptions": {
+    "module": "commonjs",
+    "target": "es5",
+    "declaration": true,
+    "strict": true,
+    "sourceMap": true,
+    "lib": [
+      "es5",
+      "es2015.promise"
+    ]
+  }
+}