vm.detachDisk requires a device name #922

/**
 * Custom error type for errors related to detaching a disk.
 *
 * @param {string} message - Custom error message.
 * @return {Error}
 */
var DetachDiskError = createErrorClass('DetachDiskError', function(message) {
  this.message = message;
});

VM.prototype.detachDisk = function(deviceName, callback) {
  var self = this;

  if (deviceName instanceof Disk) {
    var disk = deviceName;

    if (disk.metadata.deviceName) {
      self.detachDisk(disk.metadata.deviceName, callback);
      return;
    }

    this.getMetadata(function(err, metadata) {
      if (err) {
        callback(new DetachDiskError(err.message));
        return;
      }

      var deviceName;
      var baseUrl = 'https://www.googleapis.com/compute/v1/';

      // Try to find the deviceName by matching the source of the attached disks
      // to the name of the disk provided by the user.
      for (var i = 0; !deviceName && i < metadata.disks.length; i++) {
        var attachedDisk = metadata.disks[i];
        var source = attachedDisk.source.replace(baseUrl, '');

        if (source === disk.formattedName) {
          deviceName = attachedDisk.deviceName;
        }
      }

      if (deviceName) {
        self.detachDisk(deviceName, callback);
      } else {
        callback(new DetachDiskError('Could not find a deviceName for disk.'));
      }
    });
    return;
  }

  var query = {
    deviceName: deviceName
  };

  this.makeReq_('POST', '/detachDisk', query, null, callback || util.noop);
};

// system test...
it('should attach and detach a disk', function(done) {
  var disk = zone.disk(generateName());

  // This test waits on a lot of operations.
  this.timeout(90000);

  async.series([
    createDisk,
    attachDisk,
    detachDisk
  ], done);

  function createDisk(callback) {
    var config = {
      os: 'ubuntu'
    };

    disk.create(config, execAfterOperationComplete(callback));
  }

  function attachDisk(callback) {
    vm.attachDisk(disk, execAfterOperationComplete(callback));
  }

  function detachDisk(callback) {
    vm.detachDisk(disk, execAfterOperationComplete(callback));
  }
});