Awesome

The Determinate Nix Installer Action

Based on the Determinate Nix Installer, responsible for over tens of thousands of Nix installs daily. The fast, friendly, and reliable GitHub Action to install Nix with Flakes.

Supports

• ✅ Accelerated KVM on open source projects and larger runners. See GitHub's announcement for more info.
• ✅ Linux, x86_64, aarch64, and i686
• ✅ macOS, x86_64 and aarch64
• ✅ WSL2, x86_64 and aarch64
• ✅ Containers
• ✅ Valve's SteamOS
• ✅ GitHub Enterprise Server
• ✅ GitHub Hosted, self-hosted, and long running Actions Runners

Usage

on:
  pull_request:
  push:
    branches: [main]

jobs:
  lints:
    name: Build
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: DeterminateSystems/nix-installer-action@main
      - run: nix build .

With FlakeHub

To fetch private flakes from FlakeHub and Nix builds from FlakeHub Cache, update the permissions block and pass determinate: true:

on:
  pull_request:
  push:
    branches: [main]

jobs:
  lints:
    name: Build
    runs-on: ubuntu-latest
    permissions:
      id-token: "write"
      contents: "read"
    steps:
      - uses: actions/checkout@v4
      - uses: DeterminateSystems/nix-installer-action@main
        with:
          determinate: true
      - run: nix build .

See .github/workflows/ci.yml for a full example.

Advanced Usage

• If KVM is available, the installer sets up KVM so that Nix can use it ,and exports the DETERMINATE_NIX_KVM environment variable set to 1. If KVM is not available, DETERMINATE_NIX_KVM is set to 0. This can be used in combination with GitHub Actions' if syntax for turning on and off steps.

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
  • max-jobs is set to auto
• KVM is enabled by default.
• 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.

Configuration