lix-installer/README.md
Ana Hobden 7669045865
Disable auto-allocate-uids on Linux too (#638)
* Disable auto-allocate-uids on Linux too

* Fix clippy/fmt
2023-09-22 10:44:40 -07:00

18 KiB

The Determinate Nix Installer

Crates.io Docs.rs

A fast, friendly, and reliable tool to help you use Nix with Flakes everywhere.

curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install

The nix-installer has successfully completed over 500,000 installs in a number of environments, including Github Actions:

Platform Multi User root only Maturity
Linux (x86_64 & aarch64) ✓ (via systemd) Stable
MacOS (x86_64 & aarch64) Stable (See note)
Valve Steam Deck (SteamOS) Stable
WSL2 (x86_64 & aarch64) ✓ (via systemd) Stable
Podman Linux Containers ✓ (via systemd) Stable
Docker Containers Stable
Linux (i686) ✓ (via systemd) Unstable

Note

On MacOS only, removing users and/or groups may fail if there are no users who are logged in graphically.

Usage

Install Nix with the default planner and options:

curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install

Or, to download a platform specific Installer binary yourself:

$ curl -sL -o nix-installer https://install.determinate.systems/nix/nix-installer-x86_64-linux
$ chmod +x nix-installer
$ ./nix-installer

nix-installer installs Nix by following a plan made by a planner. Review the available planners:

$ ./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
          A planner for Linux installs
  steam-deck
          A planner suitable for the Valve Steam Deck running SteamOS
  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:

$ ./nix-installer install linux --help
A planner for Linux installs

Usage: nix-installer install linux [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:

$ 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

Upgrading Nix

You can upgrade Nix (to the version specified here) by running:

sudo -i nix upgrade-nix

Alternatively, you can uninstall and reinstall with a different version of the nix-installer.

Uninstalling

You can remove a nix-installer-installed Nix by running

/nix/nix-installer uninstall

As a Github Action

You can use the nix-installer-action Github Action like so:

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 .

Without systemd (Linux only)

Warning

When --init none is used, only root or users who can elevate to root privileges can run Nix:

sudo -i nix run nixpkgs#hello

If you don't use systemd, you can still install Nix by explicitly specifying the linux plan and --init none:

curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install linux --init none

In a container

In Docker/Podman containers or WSL2 instances where an init (like systemd) is not present, pass --init none.

For containers (without an init):

Warning

When --init none is used, only root or users who can elevate to root privileges can run Nix:

sudo -i nix run nixpkgs#hello
# Dockerfile
FROM ubuntu:latest
RUN apt update -y
RUN apt install curl -y
RUN curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install linux \
  --extra-conf "sandbox = false" \
  --init none \
  --no-confirm
ENV PATH="${PATH}:/nix/var/nix/profiles/default/bin"
RUN nix run nixpkgs#hello
docker build -t ubuntu-with-nix .
docker run --rm -ti ubuntu-with-nix
docker rmi ubuntu-with-nix
# or
podman build -t ubuntu-with-nix .
podman run --rm -ti ubuntu-with-nix
podman rmi ubuntu-with-nix

For containers with a systemd init:

# Dockerfile
FROM ubuntu:latest
RUN apt update -y
RUN apt install curl systemd -y
RUN curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install linux \
  --extra-conf "sandbox = false" \
  --no-start-daemon \
  --no-confirm
ENV PATH="${PATH}:/nix/var/nix/profiles/default/bin"
RUN nix run nixpkgs#hello
CMD [ "/bin/systemd" ]
podman build -t ubuntu-systemd-with-nix .
IMAGE=$(podman create ubuntu-systemd-with-nix)
CONTAINER=$(podman start $IMAGE)
podman exec -ti $CONTAINER /bin/bash
podman rm -f $CONTAINER
podman rmi $IMAGE

On some container tools, such as docker, sandbox = false can be omitted. Omitting it will negatively impact compatibility with container tools like podman.

In WSL2

We strongly recommend enabling systemd, then installing Nix as normal:

curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install

If WSLg is enabled, you can do things like open a Linux Firefox from Windows on Powershell:

wsl nix run nixpkgs#firefox

To use some OpenGL applications, you can use nixGL (note that some applications, such as blender, may not work):

wsl nix run --impure github:guibou/nixGL nix run nixpkgs#obs-studio

If enabling system is not an option, pass --init none at the end of the command:

Warning

When --init none is used, only root or users who can elevate to root privileges can run Nix:

sudo -i nix run nixpkgs#hello
curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install linux --init none

Skip confirmation

If you'd like to bypass the confirmation step, you can apply the --no-confirm flag:

curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install --no-confirm

This is especially useful when using the installer in non-interactive scripts.

Quirks

While nix-installer tries to provide a comprehensive and unquirky experience, there are unfortunately some issues which may require manual intervention or operator choices.

Using MacOS remote SSH builders, Nix binaries are not on $PATH

When connecting to a Mac remote SSH builder users may sometimes see this error:

$ nix store ping --store "ssh://$USER@$HOST"
Store URL: ssh://$USER@$HOST
zsh:1: command not found: nix-store
error: cannot connect to '$USER@$HOST'

The way MacOS populates the PATH environment differs from other environments. (Some background)

There are two possible workarounds for this:

  • (Preferred) Update the remote builder URL to include the remote-program parameter pointing to nix-store. For example:

    nix store ping --store "ssh://$USER@$HOST?remote-program=/nix/var/nix/profiles/default/bin/nix-store"
    

    If you are unsure where the nix-store binary is located, run which nix-store on the remote.

  • Update /etc/zshenv on the remote so that zsh populates the Nix path for every shell, even those that are neither interactive or login:

    # Nix
    if [ -e '/nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh' ]; then
        . '/nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh'
    fi
    # End Nix
    
    This strategy has some behavioral caveats, namely, $PATH may have unexpected contents

    For example, if $PATH gets unset then a script invoked, $PATH may not be as empty as expected:

    $ cat example.sh     
    #! /bin/zsh
    echo $PATH
    $ PATH= ./example.sh 
    /Users/ephemeraladmin/.nix-profile/bin:/nix/var/nix/profiles/default/bin:
    

    This strategy results in Nix's paths being present on $PATH twice and may have a minor impact on performance.

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:

# to build a local copy
nix build -L ".#nix-installer-static"
# to build the remote main development branch
nix build -L "github:determinatesystems/nix-installer#nix-installer-static"
# for a specific version of the installer:
export NIX_INSTALLER_TAG="v0.6.0"
nix build -L "github:determinatesystems/nix-installer/$NIX_INSTALLER_TAG#nix-installer-static"

On Mac:

# to build a local copy
nix build -L ".#nix-installer"
# to build the remote main development branch
nix build -L "github:determinatesystems/nix-installer#nix-installer"
# for a specific version of the installer:
export NIX_INSTALLER_TAG="v0.6.0"
nix build -L "github:determinatesystems/nix-installer/$NIX_INSTALLER_TAG#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, there are no system dependencies to worry about:

# to build and run a local copy
RUSTFLAGS="--cfg tokio_unstable" cargo run -- --help
# to build the remote main development branch
RUSTFLAGS="--cfg tokio_unstable" cargo install --git https://github.com/DeterminateSystems/nix-installer
nix-installer --help
# for a specific version of the installer:
export NIX_INSTALLER_TAG="v0.6.0"
RUSTFLAGS="--cfg tokio_unstable" cargo install --git https://github.com/DeterminateSystems/nix-installer --tag $NIX_INSTALLER_TAG
nix-installer --help

To make this build portable, pass --target x86_64-unknown-linux-musl.

Note

We currently require --cfg tokio_unstable as we utilize Tokio's process groups, which wrap stable std APIs, but are unstable due to it requiring an MSRV bump.

As a library

Warning

Use as a library is still experimental. This feature is likely to be removed in the future without an advocate. If you're using this, please let us know and we can make a path to stablization.

Add nix-installer to your dependencies:

cargo add nix-installer

If you are 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, which wrap stable std APIs, but are unstable due to it requiring an MSRV bump:

# .cargo/config.toml
[build]
rustflags=["--cfg", "tokio_unstable"]

Then it's possible to review the documentation:

cargo doc --open -p nix-installer

Documentation is also available via nix build:

nix build github:DeterminateSystems/nix-installer#nix-installer.doc
firefox result-doc/nix-installer/index.html

Accessing other versions

For users who desire version pinning, the version of nix-installer to use can be specified in the curl command:

VERSION="v0.6.0"
curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix/tag/${VERSION} | sh -s -- install

To discover which versions are available, or download the binaries for any release, check the Github Releases.

These releases can be downloaded and used directly:

VERSION="v0.6.0"
ARCH="aarch64-linux"
curl -sSf -L https://github.com/DeterminateSystems/nix-installer/releases/download/${VERSION}/nix-installer-${ARCH} -o nix-installer
./nix-installer install

Installation Differences

Differing from the upstream Nix installer scripts:

  • In nix.conf:
    • the nix-command and flakes features are enabled
    • bash-prompt-prefix is set
    • auto-optimise-store is set to true (On Linux only)
    • extra-nix-path is set to nixpkgs=flake:nixpkgs
  • an installation receipt (for uninstalling) is stored at /nix/receipt.json as well as a copy of the install binary at /nix/nix-installer
  • nix-channel --update is not run, ~/.nix-channels is not provisioned
  • NIX_SSL_CERT_FILE is set in the various shell profiles if the ssl-cert-file argument is used.

Motivations

The existing upstream scripts do a good job, however they are difficult to maintain.

Subtle differences in the shell implementations and tool used in the scripts make it difficult to make meaningful changes to the installer.

The Determinate Nix installer has numerous advantages:

  • keeping an installation receipt for easy uninstallation
  • offering users a chance to review an accurate, calculated install plan
  • having 'planners' which can create appropriate install plans for complicated targets
  • offering users with a failing install the chance to do a best-effort revert
  • improving performance by maximizing parallel operations
  • supporting a expanded test suite including 'curing' cases
  • supporting SELinux and OSTree based distributions without asking users to make compromises
  • operating as a single, static binary with external dependencies such as openssl, only calling existing system tools (like useradd) where necessary

It has been wonderful to collaborate with other participants in the Nix Installer Working Group and members of the broader community. The working group maintains a foundation owned fork of the installer.

Diagnostics

The goal of the Determinate Nix Installer is to successfully and correctly install Nix. The curl | sh pipeline and the installer collects a little bit of diagnostic information to help us make that true.

Here is a table of the diagnostic data we collect:

Field Use
version The version of the Determinate Nix Installer.
planner The method of installing Nix (linux, macos, steam-deck)
configured_settings The names of planner settings which were changed from their default. Does not include the values.
os_name The running operating system.
os_version The version of the operating system.
triple The architecture/operating system/binary format of your system.
is_ci Whether the installer is being used in CI (e.g. GitHub Actions).
action Either Install or Uninstall.
status One of Success, Failure, Pending, or Cancelled.
attribution Optionally defined by the user, associate the diagnostics of this run to the provided value.
failure_chain A high level description of what the failure was, if any. For example: Command("diskutil") if the command diskutil list failed.

To disable diagnostic reporting, set the diagnostics URL to an empty string by passing --diagnostic-endpoint="" or setting NIX_INSTALLER_DIAGNOSTIC_ENDPOINT="".

You can read the full privacy policy for Determinate Systems, the creators of the Determinate Nix Installer, here.