* doc: improve fetchers overview, deduplicate readme content * Improve caveat explanation and some fetchurl content * move out consumer docs on source fetching * move note on mirror URLs to the relevant section this may be better suited for the `fetchurl` reference, but it's probably better to just render that information into the manual. for now, because - contributor documentation encourages mirrors - we can expect contributors to dig into the source - linking source files is trivial in in-code documentation we leave it there. * move instructions for updating hashes to the manual * Add more clarity on text, reorganise source hash methods --------- Co-authored-by: Valentin Gagarin <valentin.gagarin@tweag.io> Co-authored-by: Dominic Mills-Howell <dominic.millz27@gmail.com> Co-authored-by: lolbinarycat <dogedoge61+github@gmail.com> |
||
---|---|---|
.. | ||
build-helpers | ||
contributing | ||
development | ||
doc-support | ||
functions | ||
hooks | ||
languages-frameworks | ||
module-system | ||
old | ||
packages | ||
stdenv | ||
tests | ||
using | ||
anchor-use.js | ||
anchor.min.js | ||
build-helpers.md | ||
common.nix | ||
contributing.md | ||
default.nix | ||
development.md | ||
functions.md | ||
lib.md | ||
manpage-urls.json | ||
manual.md.in | ||
preface.chapter.md | ||
README.md | ||
shell.nix | ||
stdenv.md | ||
style.css | ||
using-nixpkgs.md |
Contributing to the Nixpkgs reference manual
This directory houses the sources files for the Nixpkgs reference manual.
Going forward, it should only contain reference documentation. For tutorials, guides and explanations, contribute to https://nix.dev/ instead.
For documentation only relevant for contributors, use Markdown files and code comments in the source code.
Rendered documentation:
The rendering tool is nixos-render-docs, sometimes abbreviated nrd
.
Contributing to this documentation
You can quickly check your edits with nix-build
:
$ cd /path/to/nixpkgs
$ nix-build doc
If the build succeeds, the manual will be in ./result/share/doc/nixpkgs/manual.html
.
devmode
The shell in the manual source directory makes available a command, devmode
.
It is a daemon, that:
- watches the manual's source for changes and when they occur — rebuilds
- HTTP serves the manual, injecting a script that triggers reload on changes
- opens the manual in the default browser
Syntax
As per RFC 0072, all new documentation content should be written in CommonMark Markdown dialect.
Additional syntax extensions are available, all of which can be used in NixOS option documentation. The following extensions are currently used:
Tables
Tables, using the GitHub-flavored Markdown syntax.
Anchors
Explicitly defined anchors on headings, to allow linking to sections. These should be always used, to ensure the anchors can be linked even when the heading text changes, and to prevent conflicts between automatically assigned identifiers.
It uses the widely compatible header attributes syntax:
## Syntax {#sec-contributing-markup}
Note
NixOS option documentation does not support headings in general.
Inline Anchors
Allow linking arbitrary place in the text (e.g. individual list items, sentences…).
They are defined using a hybrid of the link syntax with the attributes syntax known from headings, called bracketed spans:
- []{#ssec-gnome-hooks-glib} `glib` setup hook will populate `GSETTINGS_SCHEMAS_PATH` and then `wrapGAppsHook` will prepend it to `XDG_DATA_DIRS`.
Automatic links
If you omit a link text for a link pointing to a section, the text will be substituted automatically. For example [](#chap-contributing)
.
This syntax is taken from MyST.
HTML
Inlining HTML is not allowed. Parts of the documentation gets rendered to various non-HTML formats, such as man pages in the case of NixOS manual.
Roles
If you want to link to a man page, you can use {manpage}`nix.conf(5)`
. The references will turn into links when a mapping exists in doc/manpage-urls.json
.
A few markups for other kinds of literals are also available:
{command}`rm -rfi`
{env}`XDG_DATA_DIRS`
{file}`/etc/passwd`
{option}`networking.useDHCP`
{var}`/etc/passwd`
These literal kinds are used mostly in NixOS option documentation.
This syntax is taken from MyST. Though, the feature originates from reStructuredText with slightly different syntax.
Admonitions
Set off from the text to bring attention to something.
It uses pandoc’s fenced div
s syntax:
::: {.warning}
This is a warning
:::
The following are supported:
Example admonitions require a title to work. If you don't provide one, the manual won't be built.
::: {.example #ex-showing-an-example}
# Title for this example
Text for the example.
:::
Definition lists
For defining a group of terms:
pear
: green or yellow bulbous fruit
watermelon
: green fruit with red flesh
Commit conventions
-
Make sure you read about the commit conventions common to Nixpkgs as a whole.
-
If creating a commit purely for documentation changes, format the commit message in the following way:
doc: (documentation summary) (Motivation for change, relevant links, additional information.)
Examples:
-
doc: update the kernel config documentation to use
nix-shell
-
doc: add information about
nix-update-script
Closes #216321.
-
-
If the commit contains more than just documentation changes, follow the commit message format relevant for the rest of the changes.
Documentation conventions
In an effort to keep the Nixpkgs manual in a consistent style, please follow the conventions below, unless they prevent you from properly documenting something. In that case, please open an issue about the particular documentation convention and tag it with a "needs: documentation" label. When needed, each convention explain why it exists, so you can make a decision whether to follow it or not based on your particular case. Note that these conventions are about the structure of the manual (and its source files), not about the content that goes in it. You, as the writer of documentation, are still in charge of its content.
-
Put each sentence in its own line. This makes reviews and suggestions much easier, since GitHub's review system is based on lines. It also helps identifying long sentences at a glance.
-
Use the admonition syntax for callouts and examples.
-
Provide at least one example per function, and make examples self-contained. This is easier to understand for beginners. It also helps with testing that it actually works – especially once we introduce automation.
Example code should be such that it can be passed to
pkgs.callPackage
. Instead of something like:pkgs.dockerTools.buildLayeredImage { name = "hello"; contents = [ pkgs.hello ]; }
Write something like:
{ dockerTools, hello }: dockerTools.buildLayeredImage { name = "hello"; contents = [ hello ]; }
-
When showing inputs/outputs of any REPL, such as a shell or the Nix REPL, use a format as you'd see in the REPL, while trying to visually separate inputs from outputs. This means that for a shell, you should use a format like the following:
$ nix-build -A hello '<nixpkgs>' \ --option require-sigs false \ --option trusted-substituters file:///tmp/hello-cache \ --option substituters file:///tmp/hello-cache /nix/store/zhl06z4lrfrkw5rp0hnjjfrgsclzvxpm-hello-2.12.1
Note how the input is preceded by
$
on the first line and indented on subsequent lines, and how the output is provided as you'd see on the shell.For the Nix REPL, you should use a format like the following:
nix-repl> builtins.attrNames { a = 1; b = 2; } [ "a" "b" ]
Note how the input is preceded by
nix-repl>
and the output is provided as you'd see on the Nix REPL. -
When documenting functions or anything that has inputs/outputs and example usage, use nested headings to clearly separate inputs, outputs, and examples. Keep examples as the last nested heading, and link to the examples wherever applicable in the documentation.
The purpose of this convention is to provide a familiar structure for navigating the manual, so any reader can expect to find content related to inputs in an "inputs" heading, examples in an "examples" heading, and so on. An example:
## buildImage Some explanation about the function here. Describe a particular scenario, and point to [](#ex-dockerTools-buildImage), which is an example demonstrating it. ### Inputs Documentation for the inputs of `buildImage`. Perhaps even point to [](#ex-dockerTools-buildImage) again when talking about something specifically linked to it. ### Passthru outputs Documentation for any passthru outputs of `buildImage`. ### Examples Note that this is the last nested heading in the `buildImage` section. :::{.example #ex-dockerTools-buildImage} # Using `buildImage` Example of how to use `buildImage` goes here. :::
-
Use definition lists to document function arguments, and the attributes of such arguments as well as their types. For example:
# pkgs.coolFunction Description of what `coolFunction` does. ## Inputs `coolFunction` expects a single argument which should be an attribute set, with the following possible attributes: `name` (String) : The name of the resulting image. `tag` (String; _optional_) : Tag of the generated image. _Default:_ the output path's hash.
Examples
To define a referenceable figure use the following fencing:
:::{.example #an-attribute-set-example}
# An attribute set example
You can add text before
```nix
{ a = 1; b = 2;}
```
and after code fencing
:::
Defining examples through the example
fencing class adds them to a "List of Examples" section after the Table of Contents.
Though this is not shown in the rendered documentation on nixos.org.
Figures
To define a referencable figure use the following fencing:
::: {.figure #nixos-logo}
# NixOS Logo
![NixOS logo](./nixos_logo.png)
:::
Defining figures through the figure
fencing class adds them to a List of Figures
after the Table of Contents
.
Though this is not shown in the rendered documentation on nixos.org.
Footnotes
To add a foonote explanation, use the following syntax:
Sometimes it's better to add context [^context] in a footnote.
[^context]: This explanation will be rendered at the end of the chapter.
Inline comments
Inline comments are supported with following syntax:
<!-- This is an inline comment -->
The comments will not be rendered in the rendered HTML.
Link reference definitions
Links can reference a label, for example, to make the link target reusable:
::: {.note}
Reference links can also be used to [shorten URLs][url-id] and keep the markdown readable.
:::
[url-id]: https://github.com/NixOS/nixpkgs/blob/19d4f7dc485f74109bd66ef74231285ff797a823/doc/README.md
This syntax is taken from CommonMark.
Typographic replacements
Typographic replacements are enabled. Check the list of possible replacement patterns check.
Getting help
If you need documentation-specific help or reviews, ping @NixOS/documentation-reviewers on your pull request.