The Determinate Nix Installer

nix-installer is an opinionated alternative to the official Nix install scripts.

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

The nix-installer tool is ready to use in a number of environments:

| Platform | Multi User | root only | Maturity | |------------------------------|:------------------:|:-----------:|:--------:| | Linux (x8664 & aarch64) | ✓ (via [systemd]) | ✓ | Stable | | MacOS (x8664 & aarch64) | ✓ | | Stable | | 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 |

Installation Differences

Differing from the current official 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 install 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

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:

```bash $ ./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:

```bash $ curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | NIXBUILDGROUP_NAME=nixbuilder sh -s -- install linux-multi --nix-build-group-id 4000

Or...

$ NIXBUILDGROUP_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 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 --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 --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 --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 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 linux --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, which wrap stable std APIs, but are unstable due to it requiring an MSRV bump.

As a library

Use as a library is still experimental, if you're using this, please let us know and we can make a path to stablization.

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, 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:

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