@Override
  public void open(PrincipalKeyCredential administratorCredentials, String realm, Map<String, String> kerberosConfiguration)
      throws KerberosOperationException {

    super.open(administratorCredentials, realm, kerberosConfiguration);

    if (kerberosConfiguration != null) {
      // Spit the host and port from the the admin_server_host value
      String value = kerberosConfiguration.get(KERBEROS_ENV_ADMIN_SERVER_HOST);
      HostAndPort hostAndPort = HTTPUtils.getHostAndPortFromProperty(value);

      // hostAndPort will be null if the value is not in the form of host:port
      if (hostAndPort == null) {
        // host-only and host and port values are the same since there is no port
        // both are equal to the value from the property
        adminServerHost = value;
        adminServerHostAndPort = value;
      } else {
        // host-only is the split value;
        // host and port value is the value from the property
        adminServerHost = hostAndPort.host;
        adminServerHostAndPort = value;
      }
    }

    // Pre-determine the paths to relevant Kerberos executables
    executableKinit = getExecutable("kinit");

    setOpen(init(kerberosConfiguration));
  }
A Map of environmet values to send to system command invocations.
<p>
This map is to be appened to any map of environment values passed in when
invoking {@link KerberosOperationHandler#executeCommand(String[], Map, ShellCommandUtil.InteractiveHandler)}
ambari-server/src/main/java/org/apache/ambari/server/serveraction/kerberos/KDCKerberosOperationHandler.java