Problem description

Starting with version 1.13.0, setting the grpc.ssl_target_name_override channel argument no longer correctly influences the SNI sent during the TLS handshake, resulting in ECONNRESET. This behavior breaks use cases relying on SNI-based routing, such as AWS PrivateLink setups.

Downgrading to grpc-js@1.12.6 restores the expected behavior, and the correct SNI override is applied.

Discussion

According to our investigation, we believe this line is misplaced, as it undoes the more specific assignments from lines 226 and 239.

I think something similar to this would be more appropriate:

  if (options['grpc.ssl_target_name_override']) {
    // ...
    connectionOptions.servername = sslTargetNameOverride;
  } if ('grpc.http_connect_target' in options) {
    // ...
    connectionOptions.servername = hostPort?.host ?? targetPath;
  } else {
    connectionOptions.servername = remoteHost;
  }