Adding WebSockets support

.. Copyright (c) 2013-2017 Varnish Software AS SPDX-License-Identifier: BSD-2-Clause See LICENSE file for full text of license

Adding WebSockets support

WebSockets is a technology for creating a bidirectional stream-based channel over HTTP.

To run WebSockets through Varnish you need to pipe the request and copy the Upgrade and Connection headers as follows::

sub vcl_recv {
    if (req.http.upgrade ~ "(?i)websocket") {
        return (pipe);
    }
}

sub vcl_pipe {
    if (req.http.upgrade) {
        set bereq.http.upgrade = req.http.upgrade;
        set bereq.http.connection = req.http.connection;
    }
}