public File getMasterKeyLocation() {
    File location;
    String path = getProperty(MASTER_KEY_LOCATION);

    if (StringUtils.isEmpty(path)) {
      location = new File(getServerKeyStoreDirectory(), MASTER_KEY_FILENAME_DEFAULT);
      LOG.debug("Value of {} is not set, using {}", MASTER_KEY_LOCATION, location.getAbsolutePath());
    } else {
      location = new File(path, MASTER_KEY_FILENAME_DEFAULT);
      LOG.debug("Value of {} is {}", MASTER_KEY_LOCATION, location.getAbsolutePath());
    }

    return location;
  }
Returns a File pointing where master key file is expected to be
<p/>
The master key file is named 'master'. The directory that this file is to
be found in is calculated by obtaining the directory path assigned to the
Ambari property 'security.master.key.location'; else if that value is
empty, then the directory is determined by calling
{@link #getServerKeyStoreDirectory()}.
<p/>
If it exists, this file contains the key used to decrypt values stored in
the master keystore.

@return a File that points to the master key file
@see #getServerKeyStoreDirectory()
@see #MASTER_KEY_FILENAME_DEFAULT
ambari-server/src/main/java/org/apache/ambari/server/configuration/Configuration.java