phacility/phabricator · error · Exception

Unable to test remote address against cluster whitelist: REM

Error message

Unable to test remote address against cluster whitelist: REMOTE_ADDR is not defined or not valid.

What it means

PhabricatorEnv::isClusterRemoteAddress() decides whether the current client is a cluster node: if `cluster.addresses` is configured it must classify the peer, which requires a remote address. getRemoteAddress() reads REMOTE_ADDR (honoring trusted proxy headers); when it is absent or unparseable - typically in CLI/daemon contexts where no HTTP peer exists - classification is impossible and the method throws instead of guessing. Failing closed here is deliberate: cluster auth decisions must not default to trust.

Source

Thrown at src/infrastructure/env/PhabricatorEnv.php:873

   *
   * @param string IP address.
   * @return bool True if the address is blacklisted.
   */
  public static function isBlacklistedOutboundAddress($address) {
    $blacklist = self::getEnvConfig('security.outbound-blacklist');

    return PhutilCIDRList::newList($blacklist)->containsAddress($address);
  }

  public static function isClusterRemoteAddress() {
    $cluster_addresses = self::getEnvConfig('cluster.addresses');
    if (!$cluster_addresses) {
      return false;
    }

    $address = self::getRemoteAddress();
    if (!$address) {
      throw new Exception(
        pht(
          'Unable to test remote address against cluster whitelist: '.
          'REMOTE_ADDR is not defined or not valid.'));
    }

    return self::isClusterAddress($address);
  }

  public static function isClusterAddress($address) {
    $cluster_addresses = self::getEnvConfig('cluster.addresses');
    if (!$cluster_addresses) {
      throw new Exception(
        pht(
          'This server is not configured to serve cluster requests. '.
          'Set `cluster.addresses` in the configuration to whitelist '.
          'cluster hosts before sending requests that use a cluster '.
          'authentication mechanism.'));
    }

View on GitHub (pinned to 5720a38cfe)

Solutions

1. Only invoke cluster-auth paths within a real web request; for CLI code, branch on php_sapi_name() !== 'cli' before calling isClusterRemoteAddress().
2. Fix the edge network: ensure REMOTE_ADDR reaches PHP (LB in HTTP mode, or configure trusted-proxy headers so getRemoteAddress() can recover the client address).
3. Check `cluster.addresses` is actually intended - if this host is not part of a cluster, removing the config removes the requirement.

Example fix

// before
$is_cluster = PhabricatorEnv::isClusterRemoteAddress(); // throws in CLI

// after
if (php_sapi_name() === 'cli') {
  $is_cluster = false; // no remote peer exists on the command line
} else {
  $is_cluster = PhabricatorEnv::isClusterRemoteAddress();
}

if (php_sapi_name() === 'cli' && PhabricatorEnv::getEnvConfig('cluster.addresses')) {
  // no REMOTE_ADDR exists on the CLI; do not call isClusterRemoteAddress()
  return false;
}

function hasClassifiableRemoteAddress() {
  if (php_sapi_name() === 'cli') {
    return false;
  }
  return (bool) PhabricatorEnv::getRemoteAddress();
}

try {
  $trusted = PhabricatorEnv::isClusterRemoteAddress();
} catch (Exception $ex) {
  // fail closed: unknown peer is never treated as cluster
  $trusted = false;
  phlog($ex); // but surface the misconfiguration loudly
}

When it happens

Trigger: Calling PhabricatorEnv::isClusterRemoteAddress() from a script, daemon, or worker (no REMOTE_ADDR), or from a web request where a misconfigured load balancer strips REMOTE_ADDR and no trusted X-Forwarded-For handling recovers it, while `cluster.addresses` is non-empty.

Common situations: Running bin scripts on a clustered install (cluster.addresses set) after an upgrade introduced cluster-auth checks into that code path; load balancers in TCP mode not setting REMOTE_ADDR; unit tests invoking cluster auth logic outside a request.

Related errors

• This server is not configured to serve cluster requests. Set
• Request parameter "%s" is not formatted properly. Expected a
• Request parameter "%s" is not formatted properly. Expected a
• Invalid Request (CSRF)
• This server is configured as "%s", but you are using the dom

AI-assisted analysis of phacility/phabricator@5720a38cfe (2026-08-21). Data as JSON: /api/errors/52f9116e6ab694fd. Report an issue: GitHub.