32 releases (breaking)

0.23.0 Sep 3, 2024
0.21.0 Aug 20, 2024
0.20.1 Jul 10, 2024
0.17.1 Mar 7, 2024
0.0.0-unreleased Dec 21, 2022

#36 in Unix APIs

LGPL-2.1

655KB
15K SLoC

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 2,000,000 installs in a number of environments, including Github Actions and GitLab:

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

[!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:

foo@ubuntuserver2204:~$ ./nix-installer install --help
Install Nix using a planner

By default, an appropriate planner is heuristically determined based on the system.

Some planners have additional options which can be set from the planner's subcommand.

Usage: nix-installer install [OPTIONS] [PLAN]
       nix-installer install <COMMAND>

Commands:
  linux       A planner for traditional, mutable Linux systems like Debian, RHEL, or Arch
  steam-deck  A planner for the Valve Steam Deck running SteamOS
  ostree      A planner suitable for immutable systems using ostree, such as Fedora Silverblue
  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 --nix-build-group-id 4000
# Or...
$ NIX_BUILD_GROUP_NAME=nixbuilder ./nix-installer install --nix-build-group-id 4000

Troubleshooting

Having problems with the installer? Consult our troubleshooting guide to see if your problem is covered.

Upgrading Nix

You can upgrade Nix to our currently recommended version of Nix 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 .

On GitLab

GitLab CI runners are typically Docker based and run as the root user. This means systemd is not present, so the --init none option needs to be passed to the Linux planner.

On the default GitLab.com runners, nix can be installed and used like so:

test:
  script:
    - curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install linux --no-confirm --init none
    - . /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh
    - nix run nixpkgs#hello
    - nix profile install nixpkgs#hello
    - hello

If you are using different runners, the above example may need to be adjusted.

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 systemd 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 after removing nix while nix-darwin was still installed, network requests fail

If nix was previously uninstalled without uninstalling nix-darwin first, users may experience errors similar to this:

$ nix shell nixpkgs#curl
error: unable to download 'https://cache.nixos.org/g8bqlgmpa4yg601w561qy2n576i6g0vh.narinfo': Problem with the SSL CA cert (path? access rights?) (77)

This occurs because nix-darwin provisions an org.nixos.activate-system service which remains after Nix is uninstalled. The org.nixos.activate-system service in this state interacts with the newly installed Nix and changes the SSL certificates it uses to be a broken symlink.

$ ls -lah /etc/ssl/certs
total 0
drwxr-xr-x  3 root  wheel    96B Oct 17 08:26 .
drwxr-xr-x  6 root  wheel   192B Sep 16 06:28 ..
lrwxr-xr-x  1 root  wheel    41B Oct 17 08:26 ca-certificates.crt -> /etc/static/ssl/certs/ca-certificates.crt

The problem is compounded by the matter that the nix-darwin uninstaller will not work after uninstalling Nix, since it uses Nix and requires network connectivity.

It's possible to resolve this situation by removing the org.nixos.activate-system service and the ca-certificates:

$ sudo rm /Library/LaunchDaemons/org.nixos.activate-system.plist
$ sudo launchctl bootout system/org.nixos.activate-system
$ /nix/nix-installer uninstall
$ sudo rm /etc/ssl/certs/ca-certificates.crt

Then run the nix-installer again, and it should work.

Up-to-date versions of the nix-installer will refuse to uninstall until nix-darwin is uninstalled first, helping mitigate this problem.

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 stabilization.

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"]

You'll also need to set the NIX_INSTALLER_TARBALL_PATH environment variable to point to a target-appropriate Nix installation tarball, like nix-2.21.2-aarch64-darwin.tar.xz. The contents are embedded in the resulting binary instead of downloaded at installation time.

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

Each installer version has an associated supported nix version -- if you pin the installer version, you'll also indirectly pin to the associated nix version.

You can also override the nix version via --nix-package-url or NIX_INSTALLER_NIX_PACKAGE_URL= but doing so is not recommended since we haven't tested that combination. Here are some example nix package URLs including nix version, OS and architecture:

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)
    • always-allow-substitutes is set to true
    • extra-nix-path is set to nixpkgs=flake:nixpkgs
    • max-jobs is set to auto
    • upgrade-nix-store-path-url is set to https://install.determinate.systems/nix-upgrade/stable/universal, to prevent unintentional downgrades.
  • 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
  • ssl-cert-file is set in /etc/nix/nix.conf 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:

  • survives macOS upgrades
  • 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
  • As a MacOS remote build target, ensures nix is not absent from path

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.

Installer settings

The Determinate Nix Installer provides a variety of configuration settings, some general and some on a per-command basis. All settings are available via flags or via NIX_INSTALLER_* environment variables.

General settings

These settings are available for all commands.

Flag(s) Description Default (if any) Environment variable
--log-directives Tracing directives delimited by comma NIX_INSTALLER_LOG_DIRECTIVES
--logger Which logger to use (options are compact, full, pretty, and json) compact NIX_INSTALLER_LOGGER
--verbose Enable debug logs, (-vv for trace) false NIX_INSTALLER_VERBOSITY

Installation (nix-installer install)

Flag(s) Description Default (if any) Environment variable
--diagnostic-attribution Relate the install diagnostic to a specific value NIX_INSTALLER_DIAGNOSTIC_ATTRIBUTION
--diagnostic-endpoint The URL or file path for an installation diagnostic to be sent https://install.determinate.systems/nix/diagnostic NIX_INSTALLER_DIAGNOSTIC_ENDPOINT
--explain Provide an explanation of the changes the installation process will make to your system false NIX_INSTALLER_EXPLAIN
--extra-conf Extra configuration lines for /etc/nix.conf NIX_INSTALLER_EXTRA_CONF
--force If nix-installer should forcibly recreate files it finds existing false NIX_INSTALLER_FORCE
--init Which init system to configure (if --init none Nix will be root-only) launchd (macOS), systemd (Linux) NIX_INSTALLER_INIT
--nix-build-group-id The Nix build group GID 350 (macOS), 30000 (Linux) NIX_INSTALLER_NIX_BUILD_GROUP_ID
--nix-build-group-name The Nix build group name nixbld NIX_INSTALLER_NIX_BUILD_GROUP_NAME
--nix-build-user-count The number of build users to create 32 NIX_INSTALLER_NIX_BUILD_USER_COUNT
--nix-build-user-id-base The Nix build user base UID (ascending) (NOTE: the first UID will be this base + 1) 350 (macOS), 30000 (Linux) NIX_INSTALLER_NIX_BUILD_USER_ID_BASE
--nix-build-user-prefix The Nix build user prefix (user numbers will be postfixed) _nixbld (macOS), nixbld (Linux) NIX_INSTALLER_NIX_BUILD_USER_PREFIX
--nix-package-url The Nix package URL NIX_INSTALLER_NIX_PACKAGE_URL
--no-confirm Run installation without requiring explicit user confirmation false NIX_INSTALLER_NO_CONFIRM
--no-modify-profile Modify the user profile to automatically load Nix. true NIX_INSTALLER_MODIFY_PROFILE
--proxy The proxy to use (if any); valid proxy bases are https://$URL, http://$URL and socks5://$URL NIX_INSTALLER_PROXY
--ssl-cert-file An SSL cert to use (if any); used for fetching Nix and sets ssl-cert-file in /etc/nix/nix.conf NIX_INSTALLER_SSL_CERT_FILE
--no-start-daemon Start the daemon (if not --init none) true NIX_INSTALLER_START_DAEMON

You can also specify a planner with the first argument:

nix-installer install <plan>

Alternatively, you can use the NIX_INSTALLER_PLAN environment variable:

NIX_INSTALLER_PLAN=<plan> nix-installer install

Uninstalling (nix-installer uninstall)

Flag(s) Description Default (if any) Environment variable
--explain Provide an explanation of the changes the installation process will make to your system false NIX_INSTALLER_EXPLAIN
--no-confirm Run installation without requiring explicit user confirmation false NIX_INSTALLER_NO_CONFIRM

You can also specify an installation receipt as the first argument (the default is /nix/receipt.json):

nix-installer uninstall /path/to/receipt.json

Planning (nix-installer plan)

Flag(s) Description Default (if any) Environment variable
--out-file Where to write the generated plan (in JSON format) /dev/stdout NIX_INSTALLER_PLAN_OUT_FILE

Repairing (nix-installer repair)

Flag(s) Description Default (if any) Environment variable
--no-confirm Run installation without requiring explicit user confirmation false NIX_INSTALLER_NO_CONFIRM

Self-test (nix-installer self-test)

nix-installer self-test only takes general settings.

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.

Dependencies

~19–35MB
~574K SLoC