如何在Go中自訂HTTP請求的來源IP位址？

// Create a transport based on http.DefaultTransport, but with a custom localAddr
transport := &http.Transport{
    Proxy: http.ProxyFromEnvironment,
    DialContext: (&net.Dialer{
        Timeout:   30 * time.Second,
        KeepAlive: 30 * time.Second,
        LocalAddr: localAddr, // Set the desired local IP address here
        DualStack: true,
    }).DialContext,
    MaxIdleConns:          100,
    IdleConnTimeout:       90 * time.Second,
    TLSHandshakeTimeout:   10 * time.Second,
    ExpectContinueTimeout: 1 * time.Second,
}

// Create an HTTP client using the custom transport
client := &http.Client{
    Transport: transport,
}