Lucid - HTTP/2 server in Erlang

Lucid is HTTP/2 server written in Erlang. This project was started primarily for the author to learn Erlang/OTP.

Current Status

Lucid implements latest HTTP/2 draft version and announce h2, h2-16 and h2-14 ALPN ID in NPN. The following features have been implemented:

• Flow control
• CONTINUATION
• HPACK
• Client-side padding
• Server push

Lucid works with Firefox 38. Since Erlang SSL module does not support AEAD cipher suites, Firefox refuses to connect to this server. To workaround this, open about:config in Firefox and set network.http.spdy.enforce-tls-profile to false.

It looks like Erlang/OTP 18.0 will finally support AEAD ciphers. It is currently 18.0 RC2 at the time of this writing.

Lucid also works fine with nghttp client from nghttp2 project.

Requirements

Lucid is written in purely Erlang only. Erlang/OTP 17.1 is required. Older version may work, but we have not tested.

How To Use

$ erl -pa ebin
1> make:all([load]).
2> application:start(lucid).

Now server listens to port 3000.

To enable SSL/TLS, edit ebin/lucid.app file and set ssl environment variable to true and specify certfile and keyfile to the path to server's certificate file and private key respectively:

...
{ssl, true},
{ssl_options, [{certfile, "server.crt"},
               {keyfile, "server.key"},
...

ssl application must be started before lucid:

$ erl -pa ebin
1> make:all([load]).
2> ssl:start().
3> application:start(lucid).

When accessed, server returns welcome page with request headers. To serve static file from the current working directory, replace the call handle_request to handle_request_file:

handle_cast(request, State) ->
    case handle_request_file(State) of
        stop ->
            {stop, normal, State};
        State2 ->
            {noreply, State2}
    end;