Npkg
===
[![Built with Nix][builtwithnix badge]][builtwithnix]
[![License: MIT][MIT badge]][MIT]

Npkg is a small tool that allows you to configure all your NixOS packages in one place.

Npkg is written with rust and uses [nix-editor](https://github.com/vlinkz/nix-editor) and [rnix-parser](https://github.com/nix-community/rnix-parser) to parse and edit configuration files.

# WARNING

This tool is still new/experimental, and being that it directly modifies critical files, such as `/etc/nixos/configuration.nix`, make sure you have backups in case it messes it up or deletes such files. I've already sacrificed some of my files to the void, don't let that happen to you!

# NixOS Installation

```
git clone https://github.com/vlinkz/npkg
nix-env -f npkg -i npkg
```

Then modify `~/npkg/config.json` to match your configuration.

# Usage with Nix Flakes

```
nix run github:vlinkz/npkg -- --help
```

# Declarative System Installation

### Head of `configuration.nix`

```
{ config, pkgs, lib, ... }:

let
  npkg = (import (pkgs.fetchFromGitHub {
    owner = "vlinkz";
    repo = "npkg";
    rev = "0.1.2";
    sha256 = "0000000000000000000000000000000000000000000000000000";
  })).default;
in 
{
  imports =
# rest of configuration
```

Packages:
```
environment.systemPackages =
with pkgs; [
  npkg
  # rest of your packages
];
```

# Arguments

```
USAGE:
    npkg [OPTIONS] [PACKAGES]...

ARGS:
    <PACKAGES>...    Packages

OPTIONS:
    -d, --dry-run            Do not build any packages, only edit configuration file
    -E, --env                Use nix environment 'nix-env'
    -h, --help               Print help information
    -H, --home               Use home-manager 'home.nix'
    -i, --install            Install a package
    -l, --list               List installed packages
    -o, --output <OUTPUT>    Output modified configuration file to a specified location
    -r, --remove             Remove a package
    -s, --search             Search for a package
    -S, --system             Use system 'configuration.nix'
    -u, --update             Update packages
    -V, --version            Print version information
```

# Use cases

## Installing packages

To install a package, you can run:
```
npkg -i <PACKAGE>
```
By default, this will use `nix-env` and install the package in you current environment. You can choose to use a specific available installer by using the `-S`, `-H`, or `-E` flags.

-   ```
    npkg -iS hello
    ```
    will install the `hello` package as a system package by modifying your `/etc/nixos/configuration.nix` file and then calling `nixos-rebuild switch`.

-   ```
    npkg -iH hello
    ```
    will install the `hello` package using [home-manager](https://github.com/nix-community/home-manager) if it is installed. It will modify `~/.config/nixpkgs/home.nix` and then call `home-manager switch`.

-   ```
    npkg -iE hello
    ```
    will install the `hello` package to the current nix environment by calling `nix-env -iA nixos.hello`.

## Removing packages

Very similar to installing packages:
```
npkg -r <PACKAGE>
```
The same `-S`, `-H`, and `-E` flags apply.

## Updating packages

To update all packages:
```
npkg -u
```
To specify only one type, the same `-S`, `-H`, and `-E` flags apply.

## List installed packages

```
npkg -l
```
This will list all packages installed in `/etc/nixos/configuration.nix`, `~/.config/nixpkgs/home.nix`, and with `nix-env`.

You can specify only one of these by using the `-S`, `-H`, and `-E` flags.

## Search for a package
```
npkg -s <QUERY>
```
This will print a list of packages that match the query specified. For example:
```
$ npkg -s hello greeting

* hello (2.12) (nix env)
  A program that produces a familiar, friendly greeting
```

This means that package `hello` version `2.12` is currently installed with `nix-env`.

# Configuration

A configuration file is stored in `~/.config/npkg/config.json`, by default, it contains:

```json
{
  "systemconfig": "/etc/nixos/configuration.nix",
  "homeconfig": "/home/$HOME/.config/nixpkgs/home.nix",
  "flake": null
}
```

These values can be edited to point to other locations. This is useful in [nix flake based systems](https://nixos.wiki/wiki/Flakes#Using_nix_flakes_with_NixOS) or any system where config files are not in expected locations.

# But why?

I wanted to code something as a proof of concept for using [nix-editor](https://github.com/vlinkz/nix-editor) as a backed for other tools. But so far I've been using it almost daily!

# Future plans

- Check for installed packages in other locations.
    
    For example, if installing `hello` with `home-manager`, and it's already installed with `nix-env`, give an option to switch it over.

- When removing packages, automatically detect where installed instead of defaulting to `nix-env`

- Whatever else pops into my head

[builtwithnix badge]: https://img.shields.io/badge/Built%20With-Nix-41439A?style=flat-square&logo=nixos&logoColor=white
[builtwithnix]: https://builtwithnix.org/
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[MIT]: https://opensource.org/licenses/MIT