storage: allow using custom domain name when creating signed resources

lib/storage/file.js

@@ -1219,6 +1219,8 @@ File.prototype.getSignedPolicy = function(options, callback) {
  * @param {object} config - Configuration object.
  * @param {string} config.action - "read" (HTTP: GET), "write" (HTTP: PUT), or
  * "delete" (HTTP: DELETE).
+ * @param {string=} config.cname - The cname for this bucket, i.e.,
+ * "https://cdn.example.com".
  * @param {string=} config.contentMd5 - The MD5 digest value in base64. If you
  * provide this, the client must provide this HTTP header with this same
  * value in its request.
@@ -1288,6 +1290,7 @@ File.prototype.getSignedPolicy = function(options, callback) {
  * });
  */
 File.prototype.getSignedUrl = function(config, callback) {
+ var self = this;
  var expires = new Date(config.expires);
  var expiresInSeconds = Math.round(expires / 1000); // The API expects seconds.
 
@@ -1304,8 +1307,7 @@ File.prototype.getSignedUrl = function(config, callback) {
  }[config.action];
 
  var name = encodeURIComponent(this.name);
- var targetGeneration = this.generation;
-
+ var host = config.cname || STORAGE_DOWNLOAD_BASE_URL + '/' + self.bucket.name;
  config.resource = '/' + this.bucket.name + '/' + name;
 
  this.storage.getCredentials(function(err, credentials) {
@@ -1345,14 +1347,14 @@ File.prototype.getSignedUrl = function(config, callback) {
  ].join('\n'));
  var signature = sign.sign(credentials.private_key, 'base64');
 
- var responseContentType = '';
+ var responseContentType;
  if (is.string(config.responseType)) {
  responseContentType =
  '&response-content-type=' +
  encodeURIComponent(config.responseType);
  }
 
- var responseContentDisposition = '';
+ var responseContentDisposition;
  if (is.string(config.promptSaveAs)) {
  responseContentDisposition =
  '&response-content-disposition=attachment; filename="' +
@@ -1364,20 +1366,18 @@ File.prototype.getSignedUrl = function(config, callback) {
  encodeURIComponent(config.responseDisposition);
  }
 
- var generation = '';
- if (!is.undefined(targetGeneration)) {
- generation = '&generation=' + targetGeneration;
- }
+ var signedUrl = format('{host}/{name}{id}{exp}{sig}{type}{disp}{gen}', {
+ host: host.replace(/\/*$/, ''), // Remove trailing slashes.
+ name: name,
+ id: '?GoogleAccessId=' + credentials.client_email,
+ exp: '&Expires=' + expiresInSeconds,
+ sig: '&Signature=' + encodeURIComponent(signature),
+ type: responseContentType || '',
+ disp: responseContentDisposition || '',
+ gen: self.generation ? '&generation=' + self.generation : ''
+ });
 
- callback(null, [
- 'https://storage.googleapis.com' + config.resource,
- '?GoogleAccessId=' + credentials.client_email,
- '&Expires=' + expiresInSeconds,
- '&Signature=' + encodeURIComponent(signature),
- responseContentType,
- responseContentDisposition,
- generation
- ].join(''));
+ callback(null, signedUrl);
  });
 };
 

test/storage/file.js

@@ -1832,6 +1832,37 @@ describe('File', function() {
  });
  });
 
+ describe('cname', function() {
+ it('should use a provided cname', function(done) {
+ var host = 'http://www.example.com';
+
+ file.getSignedUrl({
+ action: 'read',
+ cname: host,
+ expires: Date.now() + 5
+ }, function(err, signedUrl) {
+ assert.ifError(err);
+ assert.strictEqual(signedUrl.indexOf(host), 0);
+ done();
+ });
+ });
+
+ it('should remove trailing slashes from cname', function(done) {
+ var host = 'http://www.example.com//';
+
+ file.getSignedUrl({
+ action: 'read',
+ cname: host,
+ expires: Date.now() + 5
+ }, function(err, signedUrl) {
+ assert.ifError(err);
+ assert.strictEqual(signedUrl.indexOf(host), -1);
+ assert.strictEqual(signedUrl.indexOf(host.substr(0, -1)), 0);
+ done();
+ });
+ });
+ });
+
  describe('promptSaveAs', function() {
  it('should add response-content-disposition', function(done) {
  var disposition = 'attachment; filename="fname.ext"';