support/doc/server/code.md

   1 # Server code documentation
   2
   3 The server is a web server developed with [NodeJS](https://nodejs.org)/[Express](http://expressjs.com).
   4
   5
   6 ## Technologies
   7
   8   * [NodeJS](https://nodejs.org) -> Language
   9   * [MongoDB](https://www.mongodb.com/) -> Database
  10   * [Express](http://expressjs.com) -> Web server framework
  11   * [Mongoose](http://mongoosejs.com/) -> MongoDB object modeling
  12   * [WebTorrent](https://webtorrent.io/) -> BitTorrent over WebRTC
  13   * [Electron](http://electron.atom.io/) -> To make WebRTC inside NodeJS
  14   * [Mocha](https://mochajs.org/) -> Test framework
  15
  16
  17 ## Files
  18
  19 The server main file is [server.js](https://github.com/Chocobozzz/PeerTube/blob/master/server.js).
  20 The server modules description are in the [package.json](https://github.com/Chocobozzz/PeerTube/blob/master/package.json) at the project root.
  21 All other server files are in the [server](https://github.com/Chocobozzz/PeerTube/tree/master/server) directory:
  22
  23     server.js -> app initilization, main routes configuration (static routes...)
  24     config    -> server YAML configurations (for tests, production...)
  25     scripts   -> Scripts files for npm run
  26     server
  27     |__ controllers  -> API routes/controllers files
  28     |__ helpers      -> functions used by different part of the project (logger, utils...)
  29     |__ initializers -> functions used at the server startup (installer, database, constants...)
  30     |__ lib          -> library function (WebTorrent, OAuth2, friends logic...)
  31     |__ middlewares  -> middlewares for controllers (requests validators, requests pagination...)
  32     |__ models       -> Mongoose models for each MongoDB collection (videos, users, pods...)
  33     |__ tests        -> API tests and real world simulations (to test the decentralized feature...)
  34
  35
  36 ## Conventions
  37
  38 Uses [JavaScript Standard Style](http://standardjs.com/).
  39
  40
  41 ## Developing
  42
  43   * Install [the dependencies](https://github.com/Chocobozzz/PeerTube#dependencies)
  44   * Run `npm install` at the root directory to install all the dependencies
  45   * Run MongoDB
  46   * Run `npm run dev` to compile the client and automatically run the server. If the client files are already compiled you can simply run `NODE_ENV=test node server`
  47
  48 The `NODE_ENV=test` is set to speed up communications between pods (see [constants.js](https://github.com/Chocobozzz/PeerTube/blob/master/server/initializers/constants.js#L71)).
  49
  50 `npm run help` gives you all available commands.
  51
  52 If you want to test the decentralization feature, you can easily run 3 pods by running `npm run play`. The pods password are `test1`, `test2` and `test3`.
  53
  54
  55 ## Architecture
  56
  57 The server is composed by:
  58
  59   * a REST API
  60   * a WebTorrent Tracker
  61   * A separate Electron process
  62
  63 The seperate Electron process has the goal to seed videos through WebRTC because WebRTC directly in NodeJS is not usable for now.
  64
  65 ![Architecture scheme](https://github.com/Chocobozzz/PeerTube/blob/master/support/doc/server/upload-video.png)
  66
  67 When a user uploads a video, the rest API asks the Electron process to seed it (communicate with IPC) and then adds it to its Mongo database.
  68
  69 If a user wants to watch the video, the tracker will indicate all other users that are watching the video + the Electron process.
  70
  71 ## Newcomers
  72
  73 The server entrypoint is [server.js](https://github.com/Chocobozzz/PeerTube/blob/master/server.js). You can begin to look at this file.
  74 Then you can try to understand the [controllers](https://github.com/Chocobozzz/PeerTube/tree/master/server/controllers): they are the entrypoint of each API request.