assignment: added section on basic use cases including devshell.

src/skynet/nix.md

@@ -157,19 +157,66 @@ Since these systems share a base config (with tehir individual applications laye
 Combine that with teh ability to deploy them via our own selfhosted CI/CD we have a strong foundation to work off of.
 
 ## How we use it
-### Requirements
-{add warnign that git and git-lfs should also need to be in teh path}
+Nix cannot run on Windows, though it cna be installed into WSL.  
+Please refer to the below downloads to get a base system up and running
 
-### Download
+* [Git][git_git]
+  * As we are using a git repo this is a hard requirement.
+* [Git LFS][git_lfs]
+  * For storing non text files such as images.
+* [Nix][nix_install]
+  * Cant really use nix without thi installed.
+
+### Dev Shell
+After cloning the repo use ``nix develop`` to set up a terminal shell with the environment for working with Skynet NixOS.  
+It (currently) adds [Colmena][dev_colmena], [Agenix][dev_agenix] and [Attic][dev_attic].
+
+Another example of a dev shell can be [our discord bot][dev_discord-bot].  
+This one sets up a rust enviroment.  
+
+Of course you can also look at the dev shell for this [wiki][dev_wiki].  
+For the wiki we need to ensure that the dependencies for building it are present for all users so tehy dont have to figure out how to manually install them.
 
 ### Colmena
-#### Local
-##### Building
+[Colmena][dev_colmena] is our build and deployment tool.
 
-##### Repl
+Building is pretty easy, just run ``colmena build``.  
+Downside of that command is it will try to build everything all at once which is a *lot*.  
+A more practical approach is to build a single server or a group of servers.  
+```shell
+# build the Skynet server, names cna be found in teh flake.nix
+colmena build --on skynet
 
-#### Deployment
+# build a group of servers, in this case any one with teh tag of active-core
+colmena build --on @active-core
+```
 
+To be able to deploy to Skynet two things are required.
+* Be on teh UL network
+  * This can also be accomplished by being on the VPN.
+* Have an ssh key configured that can access the servers
+  * TLDR be an admin.
+
+### Agenix
+[Agenix][dev_agenix] is our secrets manager.  
+To be able to use this tool your pub ssh key must be in ``secrets/secrets.nix``.  
+As you would expect this is an admin only tool.  
+This file also defines the names and permissions for each secret.
+
+```shell
+# have to be in teh secrets folder for all these commands.
+cd secrets
+
+# edit the secret
+agenix -e path/to/secret.age
+
+# re-key all secrets, this is done when a new key is added or removed.
+agenix -r
+```
+
+### Attic
+[Attic][dev_attic] is teh tool that we use for our nix cache (hosted at <vhttps://nix-cache.skynet.ie/>).  
+It is not often it is used by the dev and its own [documentation][dev_attic_docs] covers it best.
 
 
 
@@ -183,4 +230,13 @@ Combine that with teh ability to deploy them via our own selfhosted CI/CD we hav
 [nix_lix]: https://lix.systems/
 [nix_lix_about]: https://lix.systems/about/
 [skynet_disconnect]: https://public.skynet.ie/postmortem/2023-01-12_Loss-of-network-access.html
-[skynet_disconnect_reenactment]: https://forgejo.skynet.ie/Computer_Society/presentations_compsoc/media/branch/main/src/slides/skynet/0_intro_img1.png
+[skynet_disconnect_reenactment]: https://forgejo.skynet.ie/Computer_Society/presentations_compsoc/media/branch/main/src/slides/skynet/0_intro_img1.png
+[git_git]: https://git-scm.com/downloads
+[git_lfs]: https://git-lfs.com/
+[nix_install]: https://nixos.org/download/
+[dev_colmena]: https://colmena.cli.rs/unstable/
+[dev_agenix]: https://github.com/ryantm/agenix
+[dev_attic]: https://github.com/zhaofengli/attic
+[dev_attic_docs]: https://docs.attic.rs/introduction.html
+[dev_discord-bot]: https://forgejo.skynet.ie/Skynet/discord-bot/src/commit/80c9191eeec29ba20ef4084713eca7fe0cab7412/flake.nix#L65
+[dev_wiki]: https://forgejo.skynet.ie/Skynet/wiki/src/commit/ab0add44756d4992fc2b2da4eba163016ccb3d1c/flake.nix#L35