add documentation

doc/setup.md

@@ -13,7 +13,8 @@ Clone that application, and then proceed with the following instructions.
 
 ### On macOS
 
-- Using [Homebrew](http://brew.sh/): `brew install supervisor nginx postgresql node`
+- Using [Homebrew](http://brew.sh/): `brew install supervisor postgresql node`
+  - If you want to use [brotli compression](https://en.wikipedia.org/wiki/Brotli) with NGINX (better compression rates for the frontend), you can install NGINX with the `ngx_brotli` module with this command: `brew tap denji/nginx && brew install nginx-full --with-brotli`. *If you already had NGINX installed, you may need to uninstall it first with `brew unlink nginx`.*Otherwise, you can install NGINX normally with `brew install nginx`.
   - Start the postgresql server:
     - to start automatically at login: `brew services start postgresql`
     - to start manually: `pg_ctl -D /usr/local/var/postgres start`
@@ -37,7 +38,50 @@ See [below](#configuration) for more information on modifying the baselayer conf
 ### On Linux
 
 - Using `apt-get`:
-  `sudo apt-get install nginx supervisor postgresql libpq-dev npm nodejs-legacy`
+  `sudo apt-get install supervisor postgresql libpq-dev npm nodejs-legacy`
+
+  - If you want to run NGINX as is (without brotli), you can simply install it with `sudo apt-get install nginx`.
+    If want to use [brotli compression](https://en.wikipedia.org/wiki/Brotli) with NGINX (to have better compression rates for the frontend), you can install NGINX with the `ngx_brotli` module with these commands:
+
+  ```
+  # install nginx from source so we can add the brotli module
+  git clone --recursive https://github.com/google/ngx_brotli.git
+  wget https://nginx.org/download/nginx-1.24.0.tar.gz
+  tar zxf nginx-1.24.0.tar.gz
+  cd ngx_brotli/deps/brotli
+  mkdir out && cd out
+  cmake -DCMAKE_BUILD_TYPE=Release -DBUILD_SHARED_LIBS=OFF -DCMAKE_C_FLAGS="-Ofast -m64 -march=native -mtune=native -flto -funroll-loops -ffunction-sections -fdata-sections -Wl,--gc-sections" -DCMAKE_CXX_FLAGS="-Ofast -m64 -march=native -mtune=native -flto -funroll-loops -ffunction-sections -fdata-sections -Wl,--gc-sections" -DCMAKE_INSTALL_PREFIX=./installed ..
+  cmake --build . --config Release --target brotlienc
+  cd ../../../..
+  export CURRENT_DIR=$(pwd)
+  cd nginx-1.24.0
+  ./configure --sbin-path=/usr/sbin/nginx --conf-path=/usr/local/nginx/nginx.conf --pid-path=/usr/local/nginx/nginx.pid --with-http_ssl_module --with-stream --with-mail=dynamic --with-http_realip_module --with-compat --add-module=${CURRENT_DIR}/ngx_brotli
+  sudo make && sudo make install
+  ```
+
+  To run it as a service, create an Nginx systemd unit file by running `sudo nano /lib/systemd/system/nginx.service` and adding the following content:
+
+  ```
+  [Unit]
+  Description=The NGINX HTTP and reverse proxy server
+  After=syslog.target network-online.target remote-fs.target nss-lookup.target
+  Wants=network-online.target
+
+  [Service]
+  Type=forking
+  PIDFile=/usr/local/nginx/nginx.pid
+  ExecStartPre=/usr/sbin/nginx -t
+  ExecStart=/usr/sbin/nginx
+  ExecReload=/usr/sbin/nginx -s reload
+  ExecStop=/bin/kill -s QUIT $MAINPID
+  PrivateTmp=true
+
+  [Install]
+  WantedBy=multi-user.target
+  ```
+
+  Then run `sudo systemctl start nginx` to start the server. To start it automatically at boot, run `sudo systemctl enable nginx`.
+
 - It may be necessary to configure your database permissions: at
   the end of your `pg_hba.conf` (typically in `/etc/postgresql/13.3/main` or `/var/lib/pgsql/data`),
   add the following lines and restart PostgreSQL