seidr/README.md

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# Seiðr

An experimental Rust GitOps/symlinkfarm orchestrator inspired by GNU Stow.

Highly unstable project, expect each change to be breaking.

[![Built with Nix](https://img.shields.io/badge/Built_With-Nix-5277C3.svg?logo=nixos&labelColor=73C3D5)](https://nixos.org)
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> **Warn**
> This is experimental, and not in the Nix sense. I'm gonna change how links work soon.

A Rust GitOps/symlinkfarm orchestrator inspired by GNU Stow. Useful for dealing
with "dotfiles", and with git support as a first class feature. Configuration is
done throug a single yaml file, giving it a paradigm that should bring joy to
those that use declarative operating systems and package managers.

Although this isn't really a case where it matters *that* much for performance,
being written in rust instead of e.g. /janky/ scripting languages does also mean
it is snappy and reliable, and the /extensive/ (hardly, but eventually) testing
helps ensure regressions aren't introduced.

That said, we're in 0.Y.Z, *here be dragons* for now (although a little less each
commit).

### Installation

    git clone https://github.com/cafkafk/seidr
    cd seidr
    cargo install --path .

### Configuration
If you want a template, you can copy the file from src/test/config.yaml:

    mkdir -p ~/.config/seidr/
    cp src/test/config.yaml ~/.config/seidr/config.yaml

You should *seriously* change this file before running any commands.

The configuration format will likely break regularly in versions 0.Y.Z.

#### Dhall

I already daily drive seidr, and here's an example of how I keep it manageable with dhall. Writing the `.yaml` files by hand and keeping them up to date quickly felt like writing aterm `.drv` files for Nix by hand... that is to say not pleasant. This somewhat makes it better.

```dhall
let {- First, we define some useful variables
    -}
    home
    : Text
    = "/home/ces/"

let config
    : Text
    = "${home}/.config/"

let gitProjectsDir
    : Text
    = "${home}/org/src/git/"

let nixosConfigName
    : Text
    = "afk-nixos"

let nixosConfigDir
    : Text
    = gitProjectsDir

let nixosConfigPath
    : Text
    = "${home}/org/src/git/${nixosConfigName}/"

let seidrConfigPath
    : Text
    = "${nixosConfigPath}/seidr/"

let {- Now, we create some schemes and types and such to make our lives easier

       TODO: We could totally also write some functions, but I haven't gotten to that yet.
    -}
    Flags
    : Type
    = < Clone | Fast >

let Repo
    : Type
    = { name : Optional Text
      , path : Optional Text
      , url : Optional Text
      , kind : Optional Text
      , flags : Optional (List Flags)
      }

let Link
    : Type
    = { name : Optional Text, rx : Text, tx : Text }

let {- Here, we define our repositories
    -}
    nixosConfigRepo
    : Repo
    = { name = Some nixosConfigName
      , path = Some nixosConfigDir
      , url = Some "git@github.com:cafkafk/afk-nixos.git"
      , kind = Some "GitRepo"
      , flags = Some [ Flags.Clone, Flags.Fast ]
      }

let ezaDevelopmentRepo
    : Repo
    = { name = Some "eza"
      , path = Some gitProjectsDir
      , url = Some "git@github.com:eza-community/eza.git"
      , kind = Some "GitRepo"
      , flags = Some [ Flags.Clone, Flags.Fast ]
      }

let {- Here, we define our repositories
    -}
    starship
    : Link
    = { name = Some "starship"
      , tx = "${seidrConfigPath}/starship.toml"
      , rx = "${config}/starship.toml"
      }

let {- And now we pull it all together -}
    categories =
      { seidr.repos
        =
        { -- dots = { name = "seidr", path = path },
          nixosConfigRepo
        , ezaDevelopmentRepo
        }
      , starship.links.starship = starship
      }

in  { categories }
```

Then it's as easy as running something like this:

```
dhall-to-yaml --file seidr.dhall --explain --output seidr.yaml
seidr -c seidr.yaml --help
```

Ofc, you replace `--help` with whatever you wanna do here.