Function replaceZeroPort

osscluster.go:895–904

replaceZeroPort substitutes originPort for a node port of "0", which is what CLUSTER SLOTS reports for TLS-only clusters started with `--port 0 --tls-port <port>`. Non-zero ports and addresses without a recoverable origin port are returned unchanged.

(nodeAddr, originPort string)

// `--port 0 --tls-port <port>`. Non-zero ports and addresses without a
// recoverable origin port are returned unchanged.
func replaceZeroPort(nodeAddr, originPort string) string {
	if originPort == "" || originPort == "0" {
		return nodeAddr
	}
	nodeHost, nodePort, err := net.SplitHostPort(nodeAddr)
	if err != nil || nodePort != "0" {
		return nodeAddr
	}
	return net.JoinHostPort(nodeHost, originPort)
}

// isLoopback returns true if the host is a loopback address.
// For IP addresses, it uses net.IP.IsLoopback().