cc785d16d4
Some checks failed
Conventional Commits / Conventional Commits (pull_request) Has been cancelled
Signed-off-by: Christina Sørensen <christina@cafkafk.com>
51 lines
2 KiB
Markdown
51 lines
2 KiB
Markdown
<!--
|
|
SPDX-FileCopyrightText: 2023-2024 Christina Sørensen
|
|
SPDX-FileContributor: Christina Sørensen
|
|
|
|
SPDX-License-Identifier: EUPL-1.2
|
|
-->
|
|
|
|
<div align="center">
|
|
|
|
# Weather - Check Cache Availablility of NixOS Configurations
|
|
|
|
A *fast* rust tool to check availability of your entire system in caches. It so
|
|
to speak "checks the weather" before going to update. Heavily inspired by [`guix
|
|
weather`](https://guix.gnu.org/manual/en/html_node/Invoking-guix-weather.html).
|
|
|
|
|
|
[](https://nixos.org)
|
|
[](CODE_OF_CONDUCT.md)
|
|
[](https://api.reuse.software/info/git.fsfe.org/reuse/api)
|
|
[](https://commission.europa.eu/content/european-union-public-licence_en)
|
|
|
|
</div>
|
|
|
|
## How It Works
|
|
|
|
The basic idea is that we construct a set of all requisites to build the
|
|
top-level of a NixOS configuration, and then query Nix cache(s) for the narinfo.
|
|
By doing this in a high concurrency, parallel task runner (i.e. tokio async
|
|
runtime), and only querying the headers for status codes, we can reach
|
|
impressive speeds, typically around 45~ network time.
|
|
|
|
One of the biggest limiting factors regarding speed is building the
|
|
`config.system.toplevel`, and finding the necessary requisites with `nix-store`.
|
|
Caching the requisites is a future goal, so that we only have to build the
|
|
`toplevel`, and then match against its derivation in cache, which should cut
|
|
down the nix part of the runtime by ~80%.
|
|
|
|
## Usage
|
|
|
|
> **Note**
|
|
> Currently, `nix-weather` only has first-class support for flakes.
|
|
|
|
General usage would be like this:
|
|
|
|
```bash
|
|
nix-weather --name myhost --config ~/git/my-nixos-config
|
|
```
|
|
|
|
Here, we specify the name of the host, as specified at the flake output
|
|
`nixosConfiguration`, and a path to the NixOS configuration flake.
|
|
|