Zig

WebSocket Connect through HTTP Proxy

See more WebSocket Examples

This example shows how to establish a WebSocket connection through an HTTP proxy server. Zig

const std = @import("std");
const chilkat = @import("chilkat");

pub fn main(init: std.process.Init) !void {
    const alloc = init.arena.allocator();

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // --------------------------------------------------
    // This example borrows the code from the REST using HTTP Proxy example.
    // We first use the Chilkat Socket object to establish a connection to the WebSocket server through an HTTP proxy.
    // Next, the Rest object uses the Socket object for its connection.
    // Finally, the WebSocket object uses the Rest object for its connection.
    //

    const rest = try chilkat.Rest.init();
    defer rest.deinit();
    const socket = try chilkat.Socket.init();
    defer socket.deinit();

    // Set the HTTP proxy domain or IP address, and port.
    socket.setHttpProxyHostname("192.168.1.79");
    socket.setHttpProxyPort(808);

    // Provide authentication to the HTTP proxy, if needed.
    socket.setHttpProxyUsername("HTTP_PROXY_LOGIN");
    socket.setHttpProxyPassword("HTTP_PROXY_PASSWORD");
    socket.setHttpProxyAuthMethod("Basic");

    // Indicate that HTTP requests (i.e. the WebSocket opening handshake) will be sent over the socket.
    // This is important for how the HTTP proxy connection is established.
    socket.setHttpProxyForHttp(true);

    // Connect to the websocket server through the HTTP proxy.
    const b_tls = false;
    const port = 80;
    const max_wait_ms = 5000;
    socket.connect("some-websocket-server.com", port, b_tls, max_wait_ms) catch {
        std.debug.print("Connect Failure Error Code: {d}\n", .{socket.getConnectFailReason()});
        std.debug.print("{s}\n", .{try socket.getLastErrorText(alloc)});
        return;
    };

    // Tell the Rest object to use the connected socket.
    rest.useConnection(socket, true) catch {
        std.debug.print("{s}\n", .{try rest.getLastErrorText(alloc)});
        return;
    };

    const ws = try chilkat.WebSocket.init();
    defer ws.deinit();

    // Tell the WebSocket to use this connection.
    ws.useConnection(rest) catch {
        std.debug.print("{s}\n", .{try ws.getLastErrorText(alloc)});
        return;
    };

    // Add the standard WebSocket open handshake headers that will be needed.
    // (This adds the required HTTP request headers to the rest object.)
    ws.addClientHeaders() catch {};

    // Add any additional headers that might be desired.
    // Two common WebSocketSpecific headers are "Sec-WebSocket-Protocol" and "Origin".
    rest.addHeader("Sec-WebSocket-Protocol", "x-some-websocket-subprotocol") catch {};
    rest.addHeader("Origin", "http://some-websocket-server.com") catch {};

    // Do the open handshake.
    const response_body = rest.fullRequestNoBody(alloc, "GET", "/something") catch {
        std.debug.print("{s}\n", .{try rest.getLastErrorText(alloc)});
        return;
    };

    // If successful, the HTTP response status code should be 101,
    // and the response body will be empty. (If it failed, we'll have a look
    // at the response body..)
    const status_code = rest.getResponseStatusCode();
    std.debug.print("Response status code: {d}\n", .{status_code});

    if (status_code != 101) {
        std.debug.print("{s}\n", .{response_body});
        std.debug.print("-- Failed because of unexpected response status code.\n", .{});
        return;
    }

    // We have the expected 101 response, so let's now validate the
    // contents of the response, such as the value sent by the server in the
    // Sec-WebSocket-Accept header.
    ws.validateServerHandshake() catch {
        std.debug.print("{s}\n", .{try ws.getLastErrorText(alloc)});
        return;
    };

    std.debug.print("WebSocket connection successful.\n", .{});

    // The application may now begin sending and receiving frames on the WebSocket connection.
    // (At this point, we're done with the rest and socket objects...)

    std.debug.print("Success.\n", .{});
}