# The Determinate Nix Installer Action Based on the [Determinate Nix Installer](https://github.com/DeterminateSystems/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](https://github.blog/changelog/2023-02-23-hardware-accelerated-android-virtualization-on-actions-windows-and-linux-larger-hosted-runners/) 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 ```yaml 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, update the `permissions` block and pass `flakehub: true`: ```yaml 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: flakehub: true - run: nix build . ``` See [`.github/workflows/ci.yml`](.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](https://github.com/NixOS/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 | Parameter | Description | Type | Default | | :---------------------- | :----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | :----------------------------------------- | :------------------------------------------------------------- | | `backtrace` | The setting for [`RUST_BACKTRACE`][backtrace] | string | | | `extra-args` | Extra arguments to pass to the planner (prefer using structured `with:` arguments unless using a custom [planner]!) | string | | | `extra-conf` | Extra configuration lines for `/etc/nix/nix.conf` (includes `access-tokens` with `secrets.GITHUB_TOKEN` automatically if `github-token` is set) | string | | | `flakehub` | Log in to FlakeHub to pull private flakes using the GitHub Actions [JSON Web Token](https://jwt.io) (JWT), which is bound to the `api.flakehub.com` audience. | Boolean | `false` | | `force-docker-shim` | Force the use of Docker as a process supervisor. This setting is automatically enabled when necessary. | Boolean | `false` | | `github-token` | A [GitHub token] for making authenticated requests (which have a higher rate-limit quota than unauthenticated requests) | string | `${{ github.token }}` | | `github-server-url` | The URL for the GitHub server, to use with the `github-token` token. Defaults to the current GitHub server, supporting GitHub Enterprise Server automatically. Only change this value if the provided `github-token` is for a different GitHub server than the current server. | string | `${{ github.server }}` | | `init` | The init system to configure (requires `planner: linux-multi`) | enum (`none` or `systemd`) | | | `kvm` | Automatically configure the GitHub Actions Runner for NixOS test support, if the host supports it. | Boolean | `true` | | `local-root` | A local `nix-installer` binary root. Overrides the `nix-installer-url` setting (a `nix-installer.sh` should exist, binaries should be named `nix-installer-$ARCH`, eg. `nix-installer-x86_64-linux`). | Boolean | `false` | | `log-directives` | A list of [tracing directives], comma separated with `-`s replaced with `_` (eg. `nix_installer=trace`) | string | | | `logger` | The logger to use during installation | enum (`pretty`, `json`, `full`, `compact`) | | | `mac-case-sensitive` | Use a case-sensitive volume (`planner: macos` only) | Boolean | `false` | | `mac-encrypt` | Force encryption on the volume (`planner: macos` only) | Boolean | `false` | | `mac-root-disk` | The root disk of the target (`planner: macos` only) | string | | | `mac-volume-label` | The label for the created [APFS] volume (`planner: macos` only) | string | | | `modify-profile` | Modify the user [profile] to automatically load Nix | Boolean | `false` | | `nix-build-group-id` | The Nix build group GID | integer | | | `nix-build-group-name` | The Nix build group name | string | | | `nix-build-user-base` | The Nix build user base UID (ascending) | integer | | | `nix-build-user-count` | The number of build users to create | integer | 32 | | `nix-build-user-prefix` | The Nix build user prefix (user numbers will be postfixed) | string | | | `source-branch` | The branch of `nix-installer` to use (conflicts with the `source-tag`, `source-revision`, and `source-branch`) | string | | | `source-pr` | The pull request of `nix-installer` to use (conflicts with `source-tag`, `source-revision`, and `source-branch`) | integer | | | `source-revision` | The revision of `nix-installer` to use (conflicts with `source-tag`, `source-branch`, and `source-pr`) | string | | | `source-tag` | The tag of `nix-installer` to use (conflicts with `source-revision`, `source-branch`, `source-pr`) | string | | | `source-url` | A URL pointing to the `nix-installer` binary | URL | n/a (calculated) | | `nix-package-url` | The Nix package URL | URL | | | `planner` | The installation [planner] to use | enum (`linux` or `macos`) | | | `reinstall` | Force a reinstall if an existing installation is detected (consider backing up `/nix/store`) | Boolean | `false` | | `start-daemon` | If the daemon should be started, requires `planner: linux-multi` | Boolean | `false` | | `trust-runner-user` | Whether to make the runner user trusted by the Nix daemon | Boolean | `true` | | `diagnostic-endpoint` | Diagnostic endpoint url where the installer sends install [diagnostic reports](https://github.com/DeterminateSystems/nix-installer#diagnostics) to, to disable set this to an empty string | string | `https://install.determinate.systems/nix-installer/diagnostic` | | `proxy` | The proxy to use (if any), valid proxy bases are `https://$URL`, `http://$URL` and `socks5://$URL` | string | | | `ssl-cert-file` | An SSL cert to use (if any), used for fetching Nix and sets `NIX_SSL_CERT_FILE` for Nix | string | | [apfs]: https://en.wikipedia.org/wiki/Apple_File_System [backtrace]: https://doc.rust-lang.org/std/backtrace/index.html#environment-variables [github token]: https://docs.github.com/en/actions/security-guides/automatic-token-authentication [planner]: https://github.com/determinateSystems/nix-installer#usage [profile]: https://nixos.org/manual/nix/stable/package-management/profiles [tracing directives]: https://docs.rs/tracing-subscriber/latest/tracing_subscriber/filter/struct.EnvFilter.html#directives