janus-gateway: use nixpkgs-unstable's derivation

This is in nixpkgs-unstable now, thus can be dropped once 21.11 (?) is
released.  For now, drop our own derivation in favour of what's coming.

pkgs/janus-gateway/default.nix

@@ -1,32 +1,18 @@
-{ stdenv, lib, fetchFromGitHub
-, jansson
-, libconfig
-, libnice
-, openssl
-, srtp
-, usrsctp
-, libmicrohttpd
-, libwebsockets
-, gnumake
-#, cmake
-, rabbitmq-c
-#, paho-mqtt-c
-, nanomsg
-, curl
-, sofia_sip
-, libopus
-, libogg
-, lua
-, glib
-, zlib
-, pkgconfig
-, gengetopt
-, autoconf
-, automake
-, libtool
-, libuv
+{ lib, stdenv, fetchFromGitHub, autoreconfHook, pkg-config, gengetopt
+, glib, libconfig, libnice, jansson, boringssl, zlib, srtp, libuv
+, libmicrohttpd, curl, libwebsockets, sofia_sip, libogg, libopus
+, usrsctp, ffmpeg
 }:
 
+let
+  libwebsockets_janus = libwebsockets.overrideAttrs (_: {
+    configureFlags = [
+      "-DLWS_MAX_SMP=1"
+      "-DLWS_WITHOUT_EXTENSIONS=0"
+    ];
+  });
+in
+
 stdenv.mkDerivation rec {
   pname = "janus-gateway";
   version = "0.11.3";
@@ -35,47 +21,39 @@ stdenv.mkDerivation rec {
     owner = "meetecho";
     repo = pname;
     rev = "v${version}";
-    sha256 = "sha256-/x0oo29zsnmyKw3QGXbnhMmgQJ9AefQ5cUTwY/5typY=";
+    sha256 = "15nadpz67w24f4wz8ya0kx0a1jc4wxv1kl0d5fr7kckkdyijh7gz";
   };
 
-  nativeBuildInputs = [
-    jansson
-    libconfig
-    libnice
-    openssl
-    srtp
-    usrsctp
-    libmicrohttpd
-    libwebsockets
-    gnumake
-    #cmake
-    rabbitmq-c
-    #paho-mqtt-c
-    nanomsg
-    curl
-    sofia_sip
-    libopus
-    libogg
-    lua
-    glib
-    zlib
-    pkgconfig
-    gengetopt
-    libuv
+  nativeBuildInputs = [ autoreconfHook pkg-config gengetopt ];
 
-    autoconf
-    automake
-    libtool
+  buildInputs = [
+    glib libconfig libnice jansson boringssl zlib srtp libuv libmicrohttpd
+    curl libwebsockets_janus sofia_sip libogg libopus usrsctp ffmpeg
   ];
 
   enableParallelBuilding = true;
 
-  preConfigure = "./autogen.sh";
+  configureFlags = [
+    "--enable-boringssl=${boringssl}"
+    "--enable-libsrtp2"
+    "--enable-turn-rest-api"
+    "--enable-json-logger"
+    "--enable-gelf-event-handler"
+    "--enable-post-processing"
+  ];
+
+  outputs = [ "out" "dev" "doc" "man" ];
+
+  postInstall = ''
+    moveToOutput share/janus "$doc"
+    moveToOutput etc "$doc"
+  '';
 
   meta = with lib; {
-    description = "Janus WebRTC server";
-    homepage = src.meta.homepage;
-    license = licenses.gpl3;
-    maintainers = with maintainers; [ aw ];
+    description = "General purpose WebRTC server";
+    homepage = "https://janus.conf.meetecho.com/";
+    license = licenses.gpl3Only;
+    platforms = platforms.linux;
+    maintainers = with maintainers; [ fpletz ];
   };
 }