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+Title: `home-manager`. Or: how not to yakhave
+Category: Blog
+Tags: /dev/diary, reflections, programming, nix
+Date: 2018-12-07
+
+Don't expect the bait-and-switch titles to remain forever.
+I just thought it was fitting for this one too 😉.
+
+## Some background
+
+Ever since I started venturing into computer programming and
+using more and more tools that used `dotfiles`, I've been
+frustrated at the lack of good tools when it came to synchronising
+these files.
+
+And that's not for lack of options.
+Either I disagree fundamentally with what I want a sync tool to do
+or nobody had come at the problem from the same angle as me before.
+This is not to bash on other projects or solutions.
+I know many people who are very happy with
+either keeping their dotfiles in a large git repo, symlinking manually,
+making `~` a git repo or using various tools that automate the symlink
+process.
+
+The problem I had was that not all my computers were the same.
+As in, I didn't neccessarily want the same configs on all of them.
+Because this is where it becomes complicated.
+
+I had been thinking about writing a tool to do the things I wanted to do before.
+Thinking back to my last post, about limiting scope, I never started it.
+While making a lot of drawing board attempts, I never wrote a single line of code
+because I could tell that it would lead me down a dark path.
+
+Reading about people on reddit from time to time who started their own
+"ansible but for dotfiles" projects that never went anywhere,
+I felt like I was doing the right thing by not even starting.
+
+So nothing happened for a while. Until recently.
+
+## Enter: `nix`
+
+In case you don't know it, `nix` is a functional programming language
+and pure package-manager for unix systems.
+Yes, that includes MacOS and whatnot.
+There is a linux distribution built around it called [`NixOS`] which utilises
+`nix` as a package manager and configuration language heavily.
+
+[`NixOS`]: https://nixos.org/nixos
+
+So what does pure-packaging really even mean?
+Have you ever had the situation where you upgraded your system
+and half way through something failed and now you ended up with a broken system
+because some of the packages had already changed while others had not?
+
+Yea, that's what people would call "impure packaging".
+
+With `nix` on the other hand this cannot happen,
+since packages are atomic, meaning that after something is built,
+it can't be changed again. Doing an update? New package.
+Changing a small config? New package.
+It means that not only can failing upgrades be seemlessly be rolled back
+but also that two different versions of the same library
+can easily be installed at the same time.
+
+Yes, that's right: no more "DLL hell"!
+
+Well okay so why am I fangirling about `nix` here?
+Apart from the fact that I've been dabbling with NixOS quite a bit recently,
+wanting to replace all my [Arch] installs with NixOS...
+
+## Enter: `home-manager`
+
+You already saw it in the title of this post, but I wanted to re-introduce it.
+What exactly is `home-manager`? It's `nix`, but for your userspace!
+Not only does it not require root permissions,
+meaning you can install packages just for you locally
+(well okay, `nix` can do this as well but...besides the point).
+
+More importantly, `home-manager` adds modules and utilities to manage userspace configurations.
+Everything is sourced from `~/.config/nixpkgs/` (you can move that IIRC)
+which is then used to generate all your configuration files.
+
+Config files are kept in the nix store (which is usually located at `/nix`)
+and then symlinked to their destination.
+
+Right. Now I can practically hear you all saying:
+"but didn't you say you didn't like tools that just symlinked stuff?"
+
+Well..yes, and no. Obviously symlinking a config is much nicer than having to copy them around.
+What I disliked about tools that symlink configs to places from some other place
+was that I was still responsible for manage that "other place".
+
+With `nix`, I never touch the store directly. In fact you don't ever do that!
+Instead I edit the `home.nix` configuration (or sub-configs when it gets too complicated)
+that then take some inputs, define the outputs and `nix` makes sure that the configs
+are then where they need to be.
+
+It gives me a single source of truth, but the best thing is
+that it's not a dumb source of truth: nix is a programming language!
+What that means is that I can dynamically adjust some config contents
+according to what system I'm running on, while not having to worry about
+keeping it all sane.
+
+I'm really happy I didn't write my own "ansible but for dotfiles"
+and I think I'd recommend nobody do that
+(I mean...unless that's your kink - I don't judge!).
+But I'm even more happy of having been introduced to `nix`
+and `home-manager` in particular.
+
+I'd much rather help write some re-usable modules,
+that other people can also take advantage of,
+than reinventing the wheel from scratch again.