feat(http): support HTTPS_PROXY and NO_PROXY environment variables

By default, use the system-defined HTTPS proxy settings when connecting
to the Cloudflare API. This module will use the proxy defined by
HTTPS_PROXY unless the Cloudflare API host is matched by the pattern
specified in NO_PROXY.

Bug: cloudflare#36

index.js

@@ -11,6 +11,7 @@ const prototypal = require('es-class');
 const auto = require('autocreate');
 
 const Client = require('./lib/Client');
+const proxy = require('./lib/proxy');
 
 /* eslint-disable global-require */
 const resources = {
@@ -23,6 +24,31 @@ const resources = {
 };
 /* eslint-enable global-require */
 
+/**
+ * withEnvProxy configures an HTTPS proxy if required to reach the Cloudflare API.
+ *
+ * @private
+ * @param {Object} opts - The current Cloudflare options
+ */
+const withEnvProxy = function withEnvProxy(opts) {
+  /* eslint-disable no-process-env */
+  const httpsProxy = process.env.HTTPS_PROXY || process.env.https_proxy;
+  const noProxy = process.env.NO_PROXY || process.env.no_proxy;
+  /* eslint-enable no-process-env */
+
+  if (httpsProxy) {
+    const agent = proxy.proxyAgent(
+      httpsProxy,
+      noProxy,
+      'https://api.cloudflare.com'
+    );
+
+    if (agent) {
+      opts.agent = agent;
+    }
+  }
+};
+
 /**
  * Constructs and returns a new Cloudflare API client with the specified authentication.
  *
@@ -41,10 +67,14 @@ const resources = {
 const Cloudflare = auto(
   prototypal({
     constructor: function constructor(auth) {
-      const client = new Client({
+      const opts = {
         email: auth && auth.email,
         key: auth && auth.key,
-      });
+      };
+
+      withEnvProxy(opts);
+
+      const client = new Client(opts);
 
       Object.defineProperty(this, '_client', {
         value: client,

lib/Getter.js

@@ -12,8 +12,12 @@ const assign = require('object-assign');
 const got = require('got');
 
 module.exports = prototypal({
+  constructor: function constructor(options) {
+    this._agent = options.agent;
+  },
   got(uri, options) {
     options = assign({}, options);
+    options.agent = this._agent;
 
     return got(uri, options);
   },

lib/proxy.js

@@ -0,0 +1,39 @@
+/*
+ * Copyright (C) 2014-present Cloudflare, Inc.
+
+ * This software may be modified and distributed under the terms
+ * of the MIT license.  See the LICENSE file for details.
+ */
+
+'use strict';
+
+const shouldProxy = require('should-proxy');
+const HttpsProxyAgent = require('https-proxy-agent');
+
+/**
+ * proxyAgent returns an HTTPS agent to use to access the base URL.
+ *
+ * @private
+ * @param {string} httpsProxy - HTTPS Proxy URL
+ * @param {string} noProxy - URLs that should be excluded from proxying
+ * @param {string} base - The client base URL
+ * @returns {https.Agent|null} - The HTTPS agent, if required to access the base URL.
+ */
+const proxyAgent = function proxyAgent(httpsProxy, noProxy, base) {
+  if (!httpsProxy) {
+    return null;
+  }
+  noProxy = noProxy || '';
+
+  const ok = shouldProxy(base, {
+    no_proxy: noProxy, // eslint-disable-line camelcase
+  });
+
+  if (!ok) {
+    return null;
+  }
+
+  return new HttpsProxyAgent(httpsProxy);
+};
+
+module.exports.proxyAgent = proxyAgent;

package.json

@@ -10,7 +10,9 @@
     "autocreate": "^1.1.0",
     "es-class": "^2.1.1",
     "got": "^6.3.0",
+    "https-proxy-agent": "^2.1.1",
     "object-assign": "^4.1.0",
+    "should-proxy": "^1.0.4",
     "url-pattern": "^1.0.3"
   },
   "devDependencies": {

test/proxy.js

@@ -0,0 +1,76 @@
+/*
+ * Copyright (C) 2014-present Cloudflare, Inc.
+
+ * This software may be modified and distributed under the terms
+ * of the MIT license.  See the LICENSE file for details.
+ */
+
+'use strict';
+
+const assert = require('power-assert');
+const mocha = require('mocha');
+
+const proxy = require('../lib/proxy');
+
+const describe = mocha.describe;
+const it = mocha.it;
+
+describe('proxy agents', () => {
+  it('should not return an agent when parameters are not set', done => {
+    const tests = [
+      ['', '', 'example.com'],
+      [null, null, 'http://example.com/'],
+    ];
+
+    tests.forEach(test => {
+      const agent = proxy.proxyAgent(test[0], test[1], test[2]);
+
+      assert.ok(!agent, 'agent was unexpected');
+    });
+
+    done();
+  });
+
+  it('should not return an agent when noProxy matches base', done => {
+    const tests = [
+      ['http://10.0.0.1:1234', 'example.com', 'http://example.com'],
+      ['http://10.0.0.1:1234', '.example.com', 'http://example.com'],
+      ['http://10.0.0.1:1234', 'foobar.com,.example.com', 'http://example.com'],
+    ];
+
+    tests.forEach(test => {
+      const agent = proxy.proxyAgent(test[0], test[1], test[2]);
+
+      assert.ok(!agent, 'agent was unexpected');
+    });
+
+    done();
+  });
+
+  it('should return an agent when noProxy is not set', done => {
+    const tests = [
+      ['http://10.0.0.1:1234', null, 'http://example.com'],
+      ['http://10.0.0.1:1234', '', 'http://example.com'],
+    ];
+
+    tests.forEach(test => {
+      const agent = proxy.proxyAgent(test[0], test[1], test[2]);
+
+      assert.ok(agent, 'expected an agent');
+    });
+
+    done();
+  });
+
+  it("should return an agent when noProxy doesn't match", done => {
+    const agent = proxy.proxyAgent(
+      'http://10.0.0.1:1234',
+      '.example.com',
+      'https://example.org'
+    );
+
+    assert.ok(agent, 'expected an agent');
+
+    done();
+  });
+});