BareRTC

BareRTC is a simple WebRTC-based chat room application. It is especially designed to be plugged into any existing website, with or without a pre-existing base of users.

Live demo: BareRTC Demo Chat

It is very much in the style of the old-school Flash based webcam chat rooms of the early 2000's: a multi-user chat room with DMs and some users may broadcast video and others may watch multiple video feeds in an asynchronous manner. I thought that this should be such an obvious free and open source app that should exist, but it did not and so I had to write it myself.

• Features
• Configuration
• Authentication
  • JWT Strict Mode
  • Running Without Authentication
  • Known Bugs Running Without Authentication
• Moderator Commands
• JSON APIs
• Tour of the Codebase
• Deploying This App
• License

Features

• Specify multiple Public Channels that all users have access to.
• Users can open direct message (one-on-one) conversations with each other.
• No long-term server side state: messages are pushed out as they come in.
• Users may share pictures and GIFs from their computer, which are pushed out as data: URLs (images scaled and metadata stripped by server) directly to connected chatters with no storage required.
• Users may broadcast their webcam which shows a camera icon by their name in the Who List. Users may click on those icons to open multiple camera feeds of other users they are interested in.
  • Mutual webcam options: users may opt that anyone who views their cam must also be sharing their own camera first.
  • Users may mark their own cameras as explicit/NSFW which marks the icon in red so other users can get a warning before clicking in (if NSFW is enabled in the settings.toml)
  • Users may boot people off their camera, and to the booted person it appears the same as if the broadcaster had turned their camera off completely - the chat server lies about the camera status so the booted user can't easily tell they'd been booted.
• Mobile friendly: works best on iPads and above but adapts to smaller screens well.
• WebRTC means peer-to-peer video streaming so cheap on hosting costs!
• Simple integration with your existing userbase via signed JWT tokens.
• User configurable sound effects to be notified of DMs or users entering/exiting the room.
• Operator commands
  • /kick users
  • /ban users (and /unban, /bans to list)
  • /nsfw to tag a user's camera as explicit
  • /shutdown to gracefully reboot the server
  • /kickall to kick EVERYBODY off the server (e.g., for mandatory front-end reload for new features)
  • /op and /deop users (give temporary mod control)
  • /help to get in-chat help for moderator commands

The BareRTC project also includes a Chatbot implementation so you can provide an official chatbot for fun & games & to auto moderate your chat room!

Configuration

On first run it will create the default settings.toml file for you which you may then customize to your liking:

Version = 2
Title = "BareRTC"
Branding = "BareRTC"
WebsiteURL = "https://www.example.com"
CORSHosts = ["https://www.example.com"]
PermitNSFW = true
UseXForwardedFor = true
WebSocketReadLimit = 41943040
MaxImageWidth = 1280
PreviewImageWidth = 360

[JWT]
  Enabled = false
  Strict = true
  SecretKey = ""

[[PublicChannels]]
  ID = "lobby"
  Name = "Lobby"
  Icon = "fa fa-gavel"
  WelcomeMessages = ["Welcome to the chat server!", "Please follow the basic rules:\n\n1. Have fun\n2. Be kind"]

[[PublicChannels]]
  ID = "offtopic"
  Name = "Off Topic"
  WelcomeMessages = ["Welcome to the Off Topic channel!"]

See Configuration for in-depth explanations on the available config settings and what they do.

Authentication

BareRTC supports custom (user-defined) authentication with your app in the form of JSON Web Tokens (JWTs). JWTs will allow your existing app to handle authentication for users by signing a token that vouches for them, and the BareRTC app will trust your signed token.

See Authentication for more information.

Moderator Commands

If you authenticate an Op user via JWT they can enter IRC-style chat commands to moderate the server. Current commands include:

• /kick <username> to disconnect a user's chat session.
• /nsfw <username> to tag a user's video feed as NSFW (if your settings.toml has PermitNSFW enabled).

JSON APIs

BareRTC provides some API endpoints that your website can call over HTTP for better integration with your site. See API for more information.

Webhook URLs

BareRTC supports setting up webhook URLs so the chat server can call out to your website in response to certain events, such as allowing users to send you reports about messages they receive on chat.

See Webhooks for more information.

Chatbot

The BareRTC project also comes with a chatbot program named BareBot which you can use to create your own bots for fun, games, and auto-moderator capabilities.

See Chatbot for more information.

Tour of the Codebase

This app uses WebSockets and WebRTC at the very simplest levels, without using a framework like Socket.io. Here is a tour of the codebase with the more interesting modules listed first.

Backend files

• cmd/BareRTC/main.go: the entry point for the Go back-end application (parses command-line flags and starts the web server)
• pkg/ contains the Go source code for the server side (the application).
  • config/ handles the settings.toml config file for the app.
  • jwt/ handles the JWT authentication logic
  • log/ is an internal logger library - not very interesting
  • util/ houses some miscellaneous utility functions, such as generating random strings or getting the user's IP address (w/ X-Forwarded-For support, etc.)
• pkg/server.go sets up the Go HTTP server and all the endpoint routes (e.g.: the /about page, static files, the WebSockets endpoint)
• pkg/websocket.go handles the WebSockets endpoint which drives 99% of the chat app (all the login, text chat, who list portions - not webcams). Some related files to this include:
  • pkg/messages.go is where I define the JSON message schema for the WebSockets protocol. Client and server messages marshal into the Message struct.
  • pkg/handlers.go is where I write "high level" chat event handlers (OnLogin, OnMessage, etc.) - the WebSocket read loop parses their message and then nicely calls my event handler based on action.
  • pkg/commands.go handles commands like /kick from moderators.
• pkg/api.go handles the JSON API endpoints from the web server.
• pkg/pages.go handles the index (w/ jwt parsing) and about pages.

Frontend files

The web/ folder holds front-end files and templates used by the Go app.

• web/templates holds Go html/template sources that are rendered server-side.
  • chat.html is the template for the main chat page (index route, /).
  • about.html is the template for the /about page.
• web/static holds the static files (scripts, stylesheets, images) for the site.
  • js/BareRTC.js does the whole front-end Vue.js app for BareRTC. The portions of the code that handle the WebSockets and WebRTC features are marked off with comment banners so you can scroll until you find them.
  • js/sounds.js handles the sound effects for the chat room.
  • css/chat.css has custom CSS for the chat room UI (mainly a lot of CSS Grid stuff for the full-screen layout).

Other front-end files are all vendored libraries or frameworks used by this app:

• Bulma CSS framework
• Font Awesome for icons.

Deploying This App

It is recommended to use a reverse proxy such as nginx in front of this app. You will need to configure nginx to forward WebSocket related headers:

server {
    server_name chat.example.com;
    listen 443 ssl http2;
    listen [::]:443 ssl http2;

    ssl_certificate /etc/letsencrypt/live/chat.example.com/fullchain.pem;
    ssl_certificate_key /etc/letsencrypt/live/chat.example.com/privkey.pem;

    # Proxy pass to BareRTC.
    location / {
        proxy_pass http://127.0.0.1:9000;

        # WebSocket headers to forward along.
        proxy_http_version 1.1;
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "Upgrade";
        proxy_set_header Host $host;
    }
}

You can run the BareRTC app itself using any service supervisor you like. I use Supervisor and you can configure BareRTC like so:

# /etc/supervisor/conf.d/barertc.conf
[program:barertc]
command = /home/user/git/BareRTC/BareRTC -address 127.0.0.1:9000
directory = /home/user/git/BareRTC
user = user

Then sudo supervisorctl reread && sudo supervisorctl add barertc to start the app.

License

GPLv3.