diff --git a/docs/rpi-documentation/Reverse Proxy.md b/docs/rpi-documentation/Reverse Proxy.md new file mode 100644 index 0000000..e82b736 --- /dev/null +++ b/docs/rpi-documentation/Reverse Proxy.md @@ -0,0 +1,46 @@ +### Reverse proxy + + +#### Introduction +A reverse proxy is for example used to host 2 services on the same port. This is useful for us because we can use the same port for the websockets and the webserver. + +#### How to use a reverse proxy +We are going to use `Apache2` as our reverse proxy. This is because it is easy to use and has a lot of documentation. It also hosts our webserver so it is easy to configure and we don't have to install another program. + +#### Additional modules +We need to enable the `proxy` and `proxy_wstunnel` modules. These are used to proxy the websockets. + +You can install them with these commands on a Raspberry Pi. For other linux distributions its may be different. + +```bash +$ sudo a2enmod proxy +$ sudo a2enmod proxy_wstunnel +``` + +#### Script +The enabled apache2 config scripts are found in `/etc/apache2/conf-enabled/`. You can create a new file with the name of your service. For example `studyarea.conf`. +```apache + + DocumentRoot /home/pi/www/html/ + + # Enable proxying WebSockets + ProxyPass /ws ws://localhost:8001/ + + # Enable proxying HTTP + ProxyPass /ws http://localhost:8080/ + +``` +Because VirtualHost is listening on port 80, we can use the same port for the webserver and the websockets. The `ProxyPass` is used to proxy the websocket. The `/ws` is the path where the websockets are hosted. Its hosted on `localhost/ws` so it kinda creates a new subdomain for the websocket. The `localhost:8001` is the address of the websockets and the `localhost:8080` is the address of the webserver. + + +`DocumentRoot` is the path where the files are for the website. + + + +### Sources: + +* https://httpd.apache.org/docs/2.4/howto/reverse_proxy.html +* https://www.serverlab.ca/tutorials/linux/web-servers-linux/how-to-reverse-proxy-websockets-with-apache-2-4/ +* https://gist.github.com/mortenege/91ec6fe02dca6f736303a00f8cea2731 +* https://www.jscape.com/blog/forward-proxy-vs-reverse-proxy#:~:text=While%20a%20forward%20proxy%20proxies,is%20providing%20file%20transfer%20services. +* https://webmasters.stackexchange.com/questions/143106/functional-difference-between-proxypass-and-proxypassreverse-in-apache \ No newline at end of file