Prerequisites and better clarification

docs/dev-guide/web.md

@@ -7,21 +7,88 @@ sidebar_label: Start
 Welcome to the developers guide for web! This guide will help you setup a development
 environment to start working on the Jitsi Meet codebase.
 
-## Building the sources
+
+## Prerequisites
+
+The setup for the development environment uses `make`, a native command from GNU/Linux. **This guide assumes that you have a Linux system with Ubuntu or Debian, or Windows Subsystem for Linux (WSL)[https://en.wikipedia.org/wiki/Windows_Subsystem_for_Linux]**. If you have iOS or other Linux distro, the process should of the installation of packages will be diferent depending on your OS.
 
 :::note
 Node.js >= 12 and npm >= 6 are required.
 :::
 
-On Debian/Ubuntu systems, the required packages can be installed with:
-- Download "Linux Binaries (x64)" from https://nodejs.org/en/download/
-- Install Node.js following these instructions: https://github.com/nodejs/help/wiki/Installation
+1. Install `nodejs` and `npm`
+
+The easiest way to install `nodejs` and `npm` is to run
 
-To build the Jitsi Meet application, just type
+```bash
+sudo apt-get install nodejs npm
 ```
-make
+
+Verify that the version of `nodejs` is >= 12 and the version of `npm`>= 6 with
+
+```bash
+node -v && npm -v
+```
+
+A result that looks good is, for example,
+
+```
+v12.18.3
+6.14.6
+```
+
+2. Install `npm` dependencies
+
+Run
+
+```bash
+npm update
+npm install webpack
+
+```
+
+Do NOT run these as the `root` user. These commands are intended to work from a normal user.
+
+
+3. *(OPTIONAL: only for Windows WSL)*
+
+Install nginx, a web server that will be used to host Jisti, with
+
+```bash
+sudo apt-get install nginx
+```
+
+Once you've done in, it is a good idea to restart the service. It also starts it if it wasn't already started. Run
+
+```bash
+sudo service nginx restart
+```
+
+If we are developing in a Windows WSL, we will need to access to the `localhost` service exposed inside the Windows WSL. In order to do so, we need to open the port of the firewall of the Windows WSL. We will install a simple firewall manager called `ufw`. In theory, if you access a service from internet with your Windows WSL, it will first pass the firewall of the local Windows machine, so nothing should happen, but beware that these ports will remain open in the Windows WSL. 
+
+```bash
+sudo apt-get install ufw
+
+sudo ufw allow 8000/tcp
+sudo ufw allow 8443/tcp
+sudo ufw allow 4443/tcp
+sudo ufw allow in 10000:20000/udp
+```
+
+
+
+## Development environment
+
+Clone the official repo:
+
+```bash
+git clone https://github.com/jitsi/jitsi-meet
+cd ./jitsi-meet/
+
+npm update && npm install
 ```
 
+
 ### Running with webpack-dev-server for development
 
 Use the following command in your terminal:
@@ -30,20 +97,43 @@ Use the following command in your terminal:
 make dev
 ```
 
-By default the backend deployment used is `alpha.jitsi.net`. You can point the Jitsi Meet app at a different backend by using a proxy server. To do this, set the WEBPACK_DEV_SERVER_PROXY_TARGET variable:
+By default the backend deployment used is `alpha.jitsi.net`. The path to this variable is under `/jitsi-meet/webpack.config.js`. You can point the Jitsi Meet app at a different backend by using a proxy server. To do this, set the WEBPACK_DEV_SERVER_PROXY_TARGET variable:
+
 
 ```bash
 export WEBPACK_DEV_SERVER_PROXY_TARGET=https://your-example-server.com
 make dev
 ```
 
-The app should be running at https://localhost:8080/
+**Congratulations! The app should be running at https://localhost:8080/**
+
+
+
+*(OPTIONAL: only for Windows WSL)*
+In order to access the application from a browser in the local Windows machine, run
+
+
+```bash
+export WEBPACK_DEV_SERVER_PROXY_TARGET="https://$HOST-MACHINE-IP-ADDRESS:8080"
+make dev
+```
+
 
 #### Certificate Error
 
 Browsers may show a certificate error since the development certificate is self-signed. It's safe to disregard those
 warning and continue to your site.
 
+
+### Building the sources
+
+
+To build the Jitsi Meet application from the source, just run
+```
+make
+```
+
+
 ### Building .debs
 
 To make a deb you can easily deploy to a public test server, ensure you have the lib-jitsi-meet sources you wish, then:
@@ -57,3 +147,10 @@ You'll have a bunch of .deb files in the parent directory, and can push the upda
 ### Running from source on existing deployment
 
 Follow the document https://community.jitsi.org/t/how-to-how-to-build-jitsi-meet-from-source-a-developers-guide/75422
+
+
+:::note
+If you have any problem during the installation of the development environment, please first look ar the following community guide:
+https://community.jitsi.org/t/how-to-how-to-build-jitsi-meet-from-source-a-developers-guide/75422
+:::
+