```

### 3. Configuring Prometheus

#### 3.1 Authenticated Prometheus config

> If MinIO is configured to expose metrics without authentication, you don't need to use `mc` to generate prometheus config. You can skip reading further and move to 3.2 section.

        assertEquals(messageCode, exception.getMessageCode());
    }

    @Test
    public void test_messageWithSpecialCharacters() {
        // Setup
        final String message = "Error: Failed to authenticate user <******@****.***> with special chars: #$%&*()!@";
        final VaMessenger<FessMessages> messageCode = messages -> messages.addErrorsSsoLoginError(UserMessages.GLOBAL_PROPERTY_KEY);

      Header("if-unmodified-since", ""),
      Header("last-modified", ""),
      Header("link", ""),
      Header("location", ""),
      Header("max-forwards", ""),
      Header("proxy-authenticate", ""),
      Header("proxy-authorization", ""),
      Header("range", ""),
      Header("referer", ""),
      Header("refresh", ""),
      Header("retry-after", ""),
      Header("server", ""),

                }
            }
            String authHeader;
            if (response == HTTP_UNAUTHORIZED) {
                authHeader = "WWW-Authenticate";
                this.authProperty = "Authorization";
            } else {
                authHeader = "Proxy-Authenticate";
                this.authProperty = "Proxy-Authorization";
            }
            String authorization = null;

        Ref: https://datatracker.ietf.org/doc/html/rfc6749
        """
        return HTTPException(
            status_code=HTTP_401_UNAUTHORIZED,
            detail="Not authenticated",
            headers={"WWW-Authenticate": "Bearer"},
        )

    async def __call__(self, request: Request) -> str | None:
        authorization = request.headers.get("Authorization")
        if not authorization:

     |
    <server>
      <id>deploymentRepo</id>
      <username>repouser</username>
      <password>repopwd</password>
    </server>
    -->

    <!-- Another sample, using keys to authenticate.
    <server>
      <id>siteServer</id>
      <privateKey>/path/to/private/key</privateKey>
      <passphrase>optional; leave empty if not used.</passphrase>
    </server>
    -->
  </servers>

                .orElseThrow(() -> new FessSystemException("Cannot create an access token."));
    }

    /**
     * Generates and saves a new access token for the current session.
     * The token is used to authenticate API requests.
     */
    public void saveToken() {
        getSessionManager().setAttribute(Constants.SEARCH_ENGINE_API_ACCESS_TOKEN, UUID.randomUUID().toString().replace("-", ""));
    }

### Enable Keycloak Admin REST API support

Before being able to authenticate against the Admin REST API using a client_id and a client_secret you need to make sure the client is configured as it follows:

- `account` client_id is a confidential client that belongs to the realm `{realm}`

import jcifs.CIFSContext;
import jcifs.CIFSException;
import jcifs.spnego.NegTokenInit;

/**
 * Base kerberos authenticator
 *
 * Uses a subject that contains kerberos credentials for use in GSSAPI context establishment.
 *
 * Be advised that short/NetBIOS name usage is not supported with this authenticator. Always specify full FQDNs.

     * 13.5.1.
     */
    private fun isEndToEnd(fieldName: String): Boolean =
      !"Connection".equals(fieldName, ignoreCase = true) &&
        !"Keep-Alive".equals(fieldName, ignoreCase = true) &&
        !"Proxy-Authenticate".equals(fieldName, ignoreCase = true) &&
        !"Proxy-Authorization".equals(fieldName, ignoreCase = true) &&
        !"TE".equals(fieldName, ignoreCase = true) &&
        !"Trailers".equals(fieldName, ignoreCase = true) &&