lix-installer/README.md
Ana Hobden d69f335703
init-less install (#188)
* wip

* Add dockerfile

* Add readme bits

* Fix logic inversion

* Relax init detection error

* Tidying heuristics

* Fix doc tests

* Mac supports start-daemon false

* Get VM tests working

* Add instructions

* Some target_os flagging

* More target flagging

* Fix lints

* Fixup more mac-only stuff

* cfg flag examples too

* Fix planner wording

* More os specific lint fixing

* More refinement on mac and the README

* Add new CI jobs to test no-daemon

* Use nix-installer-pr to point at branch

* Tests with no-init

* init/no-daemon are linux only

* nix tests support a per-distro all attribute

* Add working podman test

* Expand docker tests

* Add contributing notes

* format

* Support both podman and docker

* Update contributing

* Add Windows WSL test script for Ubuntu

* format nix tests

* More ignores to check-spelling

* Add systemd based wsl test

* We don't have root-only darwin

* Reflect review nits

* Reenable tests

* Restore mac plan

* Flag off os specific tests

* Better cfg flagging

* Remove dead comments

* Rework readme to look better with new sections

* Correct codeblock language

* Remove some warnings
2023-02-01 12:35:52 -08:00

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Markdown

# Nix Installer
[![Crates.io](https://img.shields.io/crates/v/nix-installer)](https://crates.io/crates/nix-installer)
[![Docs.rs](https://img.shields.io/docsrs/nix-installer)](https://docs.rs/nix-installer/latest/nix_installer/)
`nix-installer` is an opinionated, **experimental** Nix installer.
```bash
curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install
```
## Status
`nix-installer` is **pre-release and experimental**. It is not ready for high reliability use! *Please* don't use it on a business critical machine!
Current and planned support:
* [x] Multi-user Linux (aarch64 and x86_64) with systemd integration, no SELinux
* [x] Root-only Linux (aarch64 and x86_64) with no init integration, no SELinux
* [x] Multi-user MacOS (aarch64 and x86_64) with launchd integration
* [x] SteamOS on the Valve Steam Deck
* [ ] Multi-user Linux (aarch64 and x86_64) with systemd integration & SELinux
* [ ] Others...
## Installation Differences
Differing from the current official [Nix](https://github.com/NixOS/nix) installer scripts:
* Nix is installed with the `nix-command` and `flakes` features enabled in the `nix.conf`
* `nix-installer` stores an installation receipt (for uninstalling) at `/nix/receipt.json` as well as a copy of the install binary at `/nix/nix-installer`
## Motivations
The current Nix installer scripts do an excellent job, however they are difficult to maintain. Subtle differences in the shell implementations, and certain characteristics of bash scripts make it difficult to make meaningful changes to the installer.
Our team wishes to experiment with the idea of an installer in a more structured language and see if this is a worthwhile alternative. Along the way, we are also exploring a few other ideas, such as:
* offering users a chance to review an accurate, calculated install plan
* having 'planners' which can create appropriate install plans
* keeping an installation receipt for uninstallation
* offering users with a failing install the chance to do a best-effort revert
* doing whatever tasks we can in parallel
So far, our explorations have been quite fruitful, so we wanted to share and keep exploring.
## Usage
Install Nix with the default planner and options:
```bash
curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install
```
Or, to download a platform specific Installer binary yourself:
```bash
$ curl -sL -o nix-installer https://install.determinate.systems/nix/nix-installer-x86_64-linux
$ chmod +x nix-installer
```
> `nix-installer` will elevate itself if needed using `sudo`. If you use `doas` or `please` you may need to elevate `nix-installer` yourself.
`nix-installer` installs Nix by following a *plan* made by a *planner*. Review the available planners:
```bash
$ ./nix-installer install --help
Execute an install (possibly using an existing plan)
To pass custom options, select a planner, for example `nix-installer install linux-multi --help`
Usage: nix-installer install [OPTIONS] [PLAN]
nix-installer install <COMMAND>
Commands:
linux-multi
A standard Linux multi-user install
darwin-multi
A standard MacOS (Darwin) multi-user install
steam-deck
A specialized install suitable for the Valve Steam Deck console
help
Print this message or the help of the given subcommand(s)
# ...
```
Planners have their own options and defaults, sharing most of them in common:
```bash
$ ./nix-installer install linux-multi --help
A standard Linux multi-user install
Usage: nix-installer install linux-multi [OPTIONS]
Options:
# ...
--nix-build-group-name <NIX_BUILD_GROUP_NAME>
The Nix build group name
[env: NIX_INSTALLER_NIX_BUILD_GROUP_NAME=]
[default: nixbld]
--nix-build-group-id <NIX_BUILD_GROUP_ID>
The Nix build group GID
[env: NIX_INSTALLER_NIX_BUILD_GROUP_ID=]
[default: 3000]
# ...
```
Planners can be configured via environment variable or command arguments:
```bash
$ curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | NIX_BUILD_GROUP_NAME=nixbuilder sh -s -- install linux-multi --nix-build-group-id 4000
# Or...
$ NIX_BUILD_GROUP_NAME=nixbuilder ./nix-installer install linux-multi --nix-build-group-id 4000
```
## Uninstalling
You can remove a `nix-installer`-installed Nix by running
```bash
/nix/nix-installer uninstall
```
## As a Github Action
You can use the [`nix-installer-action`](https://github.com/DeterminateSystems/nix-installer-action) Github Action like so:
```yaml
on:
pull_request:
push:
branches: [main]
jobs:
lints:
name: Build
runs-on: ubuntu-22.04
steps:
- uses: actions/checkout@v3
- name: Install Nix
uses: DeterminateSystems/nix-installer-action@main
- name: Run `nix build`
run: nix build .
```
## In a container
In Docker/Podman containers or WSL instances where an init (like `systemd`) is not present, pass `--init none`.
> When `--init none` is used, only `root` or sudoers can run Nix:
>
> ```bash
> sudo -i nix run nixpkgs#hello
> ```
For Docker containers (without an init):
```dockerfile
# Dockerfile
FROM ubuntu:latest
RUN apt update -y
RUN apt install curl -y
COPY nix-installer /nix-installer
RUN /nix-installer install linux-multi --init none --no-confirm
ENV PATH="${PATH}:/nix/var/nix/profiles/default/bin"
RUN nix run nixpkgs#hello
```
Podman containers require `sandbox = false` in your `Nix.conf`.
For podman containers without an init:
```dockerfile
# Dockerfile
FROM ubuntu:latest
RUN apt update -y
RUN apt install curl -y
COPY nix-installer /nix-installer
RUN /nix-installer install linux-multi --extra-conf "sandbox = false" --init none --no-confirm
ENV PATH="${PATH}:/nix/var/nix/profiles/default/bin"
RUN nix run nixpkgs#hello
```
For Podman containers with an init:
```dockerfile
# Dockerfile
FROM ubuntu:latest
RUN apt update -y
RUN apt install curl systemd -y
COPY nix-installer /nix-installer
RUN /nix-installer install linux-multi --extra-conf "sandbox = false" --no-start-daemon --no-confirm
ENV PATH="${PATH}:/nix/var/nix/profiles/default/bin"
RUN nix run nixpkgs#hello
CMD [ "/usr/sbin/init" ]
```
## In WSL
If [systemd is enabled](https://ubuntu.com/blog/ubuntu-wsl-enable-systemd) it's possible to install Nix as normal using the command at the top of this document:
```bash
curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install
```
If systemd is not enabled, pass `--init none` at the end of the command:
> When `--init none` is used, only `root` or sudoers can run Nix:
>
> ```bash
> sudo -i nix run nixpkgs#hello
> ```
```bash
curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install --init none
```
## Building a binary
Since you'll be using `nix-installer` to install Nix on systems without Nix, the default build is a static binary.
Build a portable Linux binary on a system with Nix:
```bash
nix build -L github:determinatesystems/nix-installer#nix-installer-static
```
On Mac:
```bash
nix build -L github:determinatesystems/nix-installer#nix-installer
```
Then copy the `result/bin/nix-installer` to the machine you wish to run it on.
You can also add `nix-installer` to a system without Nix via `cargo`:
```bash
RUSTFLAGS="--cfg tokio_unstable" cargo install nix-installer
nix-installer --help
```
To make this build portable, pass ` --target x86_64-unknown-linux-musl`.
> We currently require `--cfg tokio_unstable` as we utilize [Tokio's process groups](https://docs.rs/tokio/1.24.1/tokio/process/struct.Command.html#method.process_group), which wrap stable `std` APIs, but are unstable due to it requiring an MSRV bump.
## As a library
Add `nix-installer` to your dependencies:
```bash
cargo add nix-installer
```
> **Building a CLI?** Check out the `cli` feature flag for `clap` integration.
You'll also need to edit your `.cargo/config.toml` to use `tokio_unstable` as we utilize [Tokio's process groups](https://docs.rs/tokio/1.24.1/tokio/process/struct.Command.html#method.process_group), which wrap stable `std` APIs, but are unstable due to it requiring an MSRV bump:
```toml
# .cargo/config.toml
[build]
rustflags=["--cfg", "tokio_unstable"]
```
Then it's possible to review the [documentation](https://docs.rs/nix-installer/latest/nix_installer/):
```bash
cargo doc --open -p nix-installer
```
Documentation is also available via `nix` build:
```bash
nix build github:DeterminateSystems/nix-installer#nix-installer.doc
firefox result-doc/nix-installer/index.html
```