common: Avoid using require to read JSON file key

lib/common/connection.js

@@ -18,6 +18,7 @@
 
 'use strict';
 
+var fs = require('fs');
 var GAPIToken = require('gapitoken');
 var req = require('request');
 var pkg = require('../../package.json');
@@ -53,12 +54,9 @@ Token.prototype.isExpired = function() {
  * @param  {Object} opts Options.
  */
 function Connection(opts) {
-  var credentials = opts.keyFilename && require(opts.keyFilename) || {};
-  // client email for the service account
-  this.email = credentials.client_email;
-  // contains the contents of a pem file
-  this.privateKey = credentials.private_key;
+  this.opts = opts || {};
 
+  this.credentials = null;
   this.scopes = opts.scopes || [];
   this.token = null; // existing access token, if exists
 
@@ -68,7 +66,6 @@ function Connection(opts) {
 
 /**
  * Retrieves a token to authorize the requests.
-
  * @param  {Function} callback  Callback.
  */
 Connection.prototype.connect = function(callback) {
@@ -92,9 +89,9 @@ Connection.prototype.connect = function(callback) {
  * @param  {Function} callback Callback function.
  */
 Connection.prototype.fetchToken = function(callback) {
-  if (!this.email || !this.privateKey) {
-    // We should be on GCE, try to retrieve token from
-    // the metadata from server.
+  var that = this;
+  if (!this.opts.keyFilename) {
+    // We should be on GCE, try to retrieve token from the metadata server.
     req({
       method: 'get',
       uri: METADATA_TOKEN_URL,
@@ -112,9 +109,24 @@ Connection.prototype.fetchToken = function(callback) {
     });
     return;
   }
+  if (!this.credentials) {
+    // read key file once and cache the contents.
+    fs.readFile(this.opts.keyFilename, function(err, data) {
+      if (err) {
+        return callback(err);
+      }
+      that.credentials = JSON.parse(data);
+      that.fetchServiceAccountToken_(callback);
+    });
+    return;
+  }
+  this.fetchServiceAccountToken_(callback);
+};
+
+Connection.prototype.fetchServiceAccountToken_ = function(callback) {
   var gapi = new GAPIToken({
-    iss: this.email,
-    key: this.privateKey,
+    iss: this.credentials.client_email,
+    key: this.credentials.private_key,
     scope: this.scopes.join(' ')
   }, function(err) {
     if (err) {

test/common/connection.js

@@ -20,69 +20,95 @@
 
 var assert = require('assert');
 var async = require('async');
-var conn = require('../../lib/common/connection.js');
+var fs = require('fs');
+var path = require('path');
+
+var connection = require('../../lib/common/connection.js');
 
 describe('Connection', function() {
-  var tokenNeverExpires = new conn.Token('token', new Date(3000, 0, 0));
-  var tokenExpired = new conn.Token('token', new Date(2011, 0, 0));
-  it('should fetch a new token if token expires', function(done) {
-    var c = new conn.Connection({
-      email: 'x@provider',
-      privateKey: '/some/path',
-      scopes: ['scope1', 'scope2']
+  var conn;
+
+  beforeEach(function() {
+    conn = new connection.Connection({
+      keyFilename: path.join(__dirname, '../testdata/privateKeyFile.json')
     });
-    c.token = tokenExpired;
-    c.fetchToken = function() {
-      done();
-    };
-    c.requester = function(opts, callback) {
-      callback(null);
-    };
-    c.req({ uri: 'https://someuri' }, function(){});
   });
 
-  it('should make other requests wait while connecting', function(done) {
-    var numTokenFetches = 0;
-    var c = new conn.Connection({
-      email: 'x@provider',
-      privateKey: '/some/path',
-      scopes: ['scope1', 'scope2']
-    });
-    c.fetchToken = function(cb) {
-      numTokenFetches++;
-      setTimeout(function() {
-        cb(null, tokenNeverExpires);
-      }, 100);
-    };
-    c.requester = function(opts, callback) {
+  it('should use a private key json file', function(done) {
+    var privateKeyFileJson = require('../testdata/privateKeyFile.json');
+    conn.fetchServiceAccountToken_ = function(callback) {
       callback(null);
     };
-
-    async.parallel([
-      function(done) { c.req({ uri: 'https://someuri' }, done); },
-      function(done) { c.req({ uri: 'https://someuri' }, done); },
-      function(done) { c.req({ uri: 'https://someuri' }, done); }
-    ], function(err) {
-      assert.equal(err, null);
-      assert.equal(numTokenFetches, 1);
-      assert.equal(c.token, tokenNeverExpires);
+    conn.fetchToken(function(err) {
+      assert.ifError(err);
+      assert.deepEqual(conn.credentials, privateKeyFileJson);
       done();
     });
   });
 
-  it('should fetch a new token if token is invalid', function(done) {
-    var c = new conn.Connection({
-      email: 'x@provider',
-      privateKey: '/some/path',
-      scopes: ['scope1', 'scope2']
+  describe('Token', function() {
+    var tokenNeverExpires = new connection.Token('token', new Date(3000, 0, 0));
+    var tokenExpired = new connection.Token('token', new Date(2011, 0, 0));
+
+    it('should fetch a new token if token expires', function(done) {
+      var c = new connection.Connection({
+        email: 'x@provider',
+        privateKey: '/some/path',
+        scopes: ['scope1', 'scope2']
+      });
+      c.token = tokenExpired;
+      c.fetchToken = function() {
+        done();
+      };
+      c.requester = function(opts, callback) {
+        callback(null);
+      };
+      c.req({ uri: 'https://someuri' }, function(){});
+    });
+
+    it('should make other requests wait while connecting', function(done) {
+      var numTokenFetches = 0;
+      var c = new connection.Connection({
+        email: 'x@provider',
+        privateKey: '/some/path',
+        scopes: ['scope1', 'scope2']
+      });
+      c.fetchToken = function(cb) {
+        numTokenFetches++;
+        setTimeout(function() {
+          cb(null, tokenNeverExpires);
+        }, 100);
+      };
+      c.requester = function(opts, callback) {
+        callback(null);
+      };
+
+      async.parallel([
+        function(done) { c.req({ uri: 'https://someuri' }, done); },
+        function(done) { c.req({ uri: 'https://someuri' }, done); },
+        function(done) { c.req({ uri: 'https://someuri' }, done); }
+      ], function(err) {
+        assert.equal(err, null);
+        assert.equal(numTokenFetches, 1);
+        assert.equal(c.token, tokenNeverExpires);
+        done();
+      });
+    });
+
+    it('should fetch a new token if token is invalid', function(done) {
+      var c = new connection.Connection({
+        email: 'x@provider',
+        privateKey: '/some/path',
+        scopes: ['scope1', 'scope2']
+      });
+      c.token = new connection.Token();
+      c.fetchToken = function() {
+        done();
+      };
+      c.requester = function(opts, callback) {
+        callback(null);
+      };
+      c.req({ uri: 'https://someuri' }, function(){});
     });
-    c.token = new conn.Token();
-    c.fetchToken = function() {
-      done();
-    };
-    c.requester = function(opts, callback) {
-      callback(null);
-    };
-    c.req({ uri: 'https://someuri' }, function(){});
   });
 });

test/testdata/privateKeyFile.json

@@ -0,0 +1,7 @@
+{
+  "private_key_id": "7",
+  "private_key": "-----BEGIN PRIVATE KEY-----\n\n-----END PRIVATE KEY-----\n",
+  "client_email": "firstpart@secondpart.com",
+  "client_id": "8",
+  "type": "service_account"
+}