Merge pull request 'feat: docs for connecting to vpn (linux)' (#35) from vpn-docs into main

Reviewed-on: Skynet/wiki#35

src/tutorials/skynet/connect_vpn.md

@@ -0,0 +1,73 @@
+# Connect to Skynet VPN
+
+## Nix (recommended)
+
+For folks who have [nix][nix] installed they can use this. 
+Details on how to use it can be found on the [github].  
+
+If you have NixOS installed you can use the following module.  
+It makes use of ``Home Manager`` to create the config file in ``$USERNAME``'s home dir.  
+Using ``vpn up`` and ``vpn down`` to control the vpn.
+
+```nix
+/*
+Config for UL VPN.
+Opens a small browser to grab the cookie
+Use ``vpn up ul`` and ``vpn down ul``
+*/
+{inputs, ...}: {
+  # https://github.com/NixOS/nixpkgs/issues/231038#issuecomment-1637903456
+  environment.etc."ppp/options".text = "ipcp-accept-remote";
+
+  home-manager.users."$USERNAME".home = {
+    file.".vpn".text = ''
+      [
+          {
+              "name": "ul",
+              "host": "ulssl.ul.ie",
+              "port": 443,
+              "default": true,
+              "cert": ""
+          }
+      ]
+    '';
+
+    packages = [
+      inputs.openfortivpn-cli.packages.x86_64-linux.default
+    ];
+  };
+}
+```
+## Linux
+
+1. Install [openfortivpn], its available in many distros repositories, it also has instructions for building from source  
+2. Run ```sudo openfortivpn ulssl.ul.ie:443 -u <studentmail here> -p "<password for studentmail>" --saml-login --trusted-cert 22edd86cce8a4d46591f0f8b63f388b98d9abc8a2eb4cd684c85172be066bac2```  
+3. Click link in terminal and verify through browser  
+4. Should now be on the vpn - can be tested with ```ssh <skynet username>@cadie.skynet.ie```  
+
+
+## Windows
+1. Install [FortiClient VPN-only][windows-forticlient].
+2. Create a new profile with teh following values:
+
+   | Field            | Value           |
+   |------------------|-----------------|
+   | Gateway          | ``ulssl.ul.ie`` |
+   | Port             | ``443``         |
+   | Enable SSO       | Ticked          |
+   | External browser | Ticked          |
+3. Connect
+   * A browser window will open up.
+4. Login using your UL ``email``/``password``.
+
+
+
+[openfortivpn]: https://github.com/adrienverge/openfortivpn
+[windows-forticlient]: https://www.fortinet.com/support/product-downloads#vpn
+
+
+
+
+
+[nix]: ../../skynet/nix.md
+[github]: https://github.com/adrienverge/openfortivpn