Function pingSiblingReplicas

enterprise/wsproxy/wsproxy.go:527–584

(ctx context.Context, logger slog.Logger, sf *singleflight.Group, derpMeshTLSConfig *tls.Config, replicas []codersdk.Replica)

}

func pingSiblingReplicas(ctx context.Context, logger slog.Logger, sf *singleflight.Group, derpMeshTLSConfig *tls.Config, replicas []codersdk.Replica) string {
	if len(replicas) == 0 {
		return ""
	}

	// Avoid pinging multiple times at once if the list hasn't changed.
	relayURLs := make([]string, len(replicas))
	for i, r := range replicas {
		relayURLs[i] = r.RelayAddress
	}
	slices.Sort(relayURLs)
	singleflightStr := strings.Join(relayURLs, " ") // URLs can't contain spaces.

	//nolint:dogsled
	errStrInterface, _, _ := sf.Do(singleflightStr, func() (any, error) {
		client := http.Client{
			Timeout: 3 * time.Second,
			Transport: &http.Transport{
				TLSClientConfig:   derpMeshTLSConfig,
				DisableKeepAlives: true,
			},
		}
		defer client.CloseIdleConnections()

		errs := make(chan error, len(replicas))
		for _, peer := range replicas {
			go func(peer codersdk.Replica) {
				err := pingReplica(ctx, client, peer)
				if err != nil {
					errs <- xerrors.Errorf("ping sibling replica %s (%s): %w", peer.Hostname, peer.RelayAddress, err)
					logger.Warn(ctx, "failed to ping sibling replica, this could happen if the replica has shutdown",
						slog.F("replica_hostname", peer.Hostname),
						slog.F("replica_relay_address", peer.RelayAddress),
						slog.Error(err),
					)
					return
				}
				errs <- nil
			}(peer)
		}

		replicaErrs := make([]string, 0, len(replicas))
		for i := 0; i < len(replicas); i++ {
			err := <-errs
			if err != nil {
				replicaErrs = append(replicaErrs, err.Error())
			}
		}

		if len(replicaErrs) == 0 {
			return "", nil
		}
		return fmt.Sprintf("Failed to dial peers: %s", strings.Join(replicaErrs, ", ")), nil
	})

	//nolint:forcetypeassert
	return errStrInterface.(string)
}