How to send http request via ssdp in typescript

I am following this tutorial: https://sdkdocs.roku.com/display/sdkdoc/External+Control+API ...trying to grab a list of devices via ssdp / http get.

        let query: string = "M-SEARCH * HTTP/1.1\r\n" +
            "HOST: 239.255.255.250:1900\r\n" +
            "MAN: \"ssdp:discover\"\r\n" +
            "ST: roku: ecp\r\n\r\n";

        this.http
            .get(query)
            .map(res => res.json())
            .subscribe(
            (data) => this.devices = data,
            (err) => this.error = err);

... but I'm getting a 404 error (also, localhost is being appended to the string):

Failed to load resource: the server responded with a status of 404 (Not Found)

http://localhost:52125/M-SEARCH%20*%20HTTP/1.1HOST:%20239.255.255.250:1900MAN:%20%22ssdp:discover%22ST:%20roku:%20ecp

Solution

SSDP uses HTTPU or HTTP over UDP. Node's HTTP client only sends data over TCP. You'll need to use a udp socket to send this manually and listen for data, or use a pre-existing library such as node-ssdp.