Release v1

.github/workflows/cicd.yml

@@ -0,0 +1,68 @@
+on: push
+
+name: CI/CD
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - uses: ./
+        with:
+          nix_archives_url: https://github.com/nixbuild/nix-quick-install-action/releases/download/v0
+          nix_version: 3.0pre20200829_f156513
+          nix_conf: experimental-features = nix-command flakes
+      - name: Build nix archives
+        id: build-nix-archives
+        run: |
+          nix build .#nix-archives
+          echo "::set-output name=result::$(readlink result)"
+      - uses: actions/upload-artifact@v2
+        with:
+          name: nix-archives
+          path: ${{ steps.build-nix-archives.outputs.result }}/
+
+  test:
+    runs-on: ubuntu-latest
+    needs: build
+    strategy:
+      matrix:
+        nix_version:
+          - 3.0pre20200829_f156513
+          - 2.3.7
+          - 2.2.2
+          - 2.1.3
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/download-artifact@v2
+        id: nix-archives
+        with:
+          name: nix-archives
+      - uses: ./
+        with:
+          nix_archives_url: file://${{steps.nix-archives.outputs.download-path}}
+          nix_version: ${{ matrix.nix_version }}
+      - name: Test nix
+        run: nix-build --version
+
+  release:
+    runs-on: ubuntu-latest
+    needs: [build, test]
+    if: github.ref == 'refs/heads/master'
+    steps:
+      - uses: actions/checkout@v2
+      - uses: actions/download-artifact@v2
+        id: nix-archives
+        with:
+          name: nix-archives
+      - uses: ./
+        with:
+          nix_archives_url: file://${{steps.nix-archives.outputs.download-path}}
+          nix_version: 3.0pre20200829_f156513
+          nix_conf: experimental-features = nix-command flakes
+      - name: Build release script
+        run: nix build .#release
+      - name: Release if needed
+        run: ./result/bin/release ${{steps.nix-archives.outputs.download-path}} ./RELEASE
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

README.md

@@ -1 +1,29 @@
-# nix-quick-install-action
+# Nix Quick Install Action
+
+This GitHub Action installs [Nix](https://nixos.org/nix/) in single-user mode.
+
+## Description
+
+To make the action as quick as possible, the installation is minimal: no
+nix-daemon, no nix channels and no `NIX_PATH`. The nix store (`/nix/store`) is
+owned by the unprivileged runner user. The action has inputs for selecting which
+Nix version to use, and to specify `nix.conf` contents.
+
+The action provides you with a fully working Nix setup, but since no `NIX_PATH`
+or channels are setup you need to handle this on your own. Nix Flakes is great
+for this, and works perfectly with this action (see below).
+[niv](https://github.com/nmattia/niv) should also work fine, but has not been
+tested yet.
+
+If this action doesn't work out for your use case, you should look at the
+[Install Nix](https://github.com/marketplace/actions/install-nix) action.
+
+## Usage
+
+Coming soon
+
+## Inputs
+
+See [action.yml](action.yml) for documentation of the available inputs.
+Available Nix versions are listed in the [release
+notes](https://github.com/nixbuild/nix-quick-install-action/releases/latest).

RELEASE

@@ -0,0 +1 @@
+v1

action.yml

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+name: Nix Quick Install
+description: Quickly installs Nix in unprivileged single-user mode
+author: Rickard Nilsson
+
+inputs:
+
+  nix_version:
+    required: true
+    default: "2.3.7"
+    description: |
+      The version of Nix that should be installed
+
+      If not specified, the latest stable Nix release is used. Note that each
+      release of nix-quick-install-action has a specific set of supported
+      Nix versions, which do not change. You can check what Nix versions are
+      supported by the version of nix-quick-install-action you're using by
+      going to https://github.com/nixbuild/nix-quick-install-action/releases
+
+  nix_conf:
+    required: false
+    description: |
+      If set, this configuration is written to a new file which is then added to
+      the NIX_USER_CONF_FILES environment variable. You can also set that
+      variable yourself to control the Nix configuration.
+
+  nix_archives_url:
+    required: false
+    description: |
+      Don't use. For bootstrapping purposes only.
+
+
+runs:
+  using: "composite"
+  steps:
+    - name: Install Nix in single-user mode
+      run: ${{ github.action_path }}/nix-quick-install.sh
+      shell: bash
+      env:
+        RELEASE_FILE: ${{ github.action_path }}/RELEASE
+        NIX_VERSION: ${{ inputs.nix_version }}
+        NIX_CONF: ${{ inputs.nix_conf }}
+        NIX_ARCHIVES_URL: ${{ inputs.nix_archives_url }}
+
+
+branding:
+  icon: zap
+  color: gray-dark

flake.nix

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+{
+  description = "nix-quick-install-action";
+
+  inputs = {
+    flake-utils.url = "github:numtide/flake-utils";
+    nixpkgs.url = "nixpkgs/nixos-unstable-small";
+    nixpkgs-nix-2_3_7.url = "nixpkgs/046427570ebe2726a2f21c3b51d84d29c86ebde5";
+    nixpkgs-nix-2_2_2.url = "nixpkgs/5399f34ad9481849720d14605ce87b81abe202e9";
+    nixpkgs-nix-2_2_2.flake = false;
+    nixpkgs-nix-2_1_3.url = "nixpkgs/2c9265c95075170ad210ed5635ecffcd36db6b84";
+    nixpkgs-nix-2_1_3.flake = false;
+  };
+
+  outputs = {
+    self, flake-utils, nixpkgs,
+    nixpkgs-nix-2_3_7, nixpkgs-nix-2_2_2, nixpkgs-nix-2_1_3
+  }: flake-utils.lib.eachSystem ["x86_64-linux"] (system:
+
+    let
+
+      inherit (nixpkgs) lib;
+
+      pkgs = nixpkgs.legacyPackages.${system};
+
+      makeNixArchive = nix:
+        pkgs.runCommand "nix-archive" {
+          buildInputs = [ nix pkgs.gnutar pkgs.zstd ];
+          closureInfo = pkgs.closureInfo { rootPaths =  [ nix ]; };
+          fileName = "nix-${nix.version}-${system}.tar.zstd";
+          inherit nix;
+        } ''
+          mkdir -p "$out" root/nix/var/nix
+          NIX_STATE_DIR="$(pwd)/root/nix/var/nix" nix-store --load-db \
+            < $closureInfo/registration
+          ln -s $nix/bin root/nix/bin
+          tar -cvT $closureInfo/store-paths -C root . | zstd - -o "$out/$fileName"
+        '';
+
+      nixArchives = lib.listToAttrs (map (nix: lib.nameValuePair
+        nix.version (makeNixArchive nix)
+      ) [
+        pkgs.nixUnstable
+        nixpkgs-nix-2_3_7.legacyPackages.${system}.nix
+        (import nixpkgs-nix-2_2_2 { inherit system; }).nix
+        (import nixpkgs-nix-2_1_3 { inherit system; }).nix
+      ]);
+
+    in rec {
+      defaultApp = apps.release;
+
+      apps.release= flake-utils.lib.mkApp { drv = packages.release; };
+
+      packages = {
+        nix-archives = pkgs.buildEnv {
+          name = "nix-archives";
+          paths = lib.attrValues nixArchives;
+        };
+        release = pkgs.writeScriptBin "release" ''
+          #!${pkgs.stdenv.shell}
+
+          PATH="${lib.makeBinPath (with pkgs; [
+            coreutils gitMinimal github-cli
+          ])}"
+
+          if [ "$GITHUB_ACTIONS" != "true" ]; then
+            echo >&2 "not running in GitHub, exiting"
+            exit 1
+          fi
+
+          set -euo pipefail
+
+          nix_archives="$1"
+          release_file="$2"
+          release="$(cat "$release_file")"
+          prev_release="$(gh release list -L 1 | cut -f 3)"
+
+          if [ "$release" = "$prev_release" ]; then
+            echo >&2 "Release tag not updated ($release)"
+            exit
+          else
+            echo >&2 "New release: $prev_release -> $release"
+            gh release create "$release" ${
+              lib.concatStringsSep " " (lib.mapAttrsToList (version: archive:
+                ''"$nix_archives/${archive.fileName}#nix-${version}-${system}"''
+              ) nixArchives)
+            } \
+              --title "$GITHUB_REPOSITORY@$release" \
+              --notes-file "${pkgs.writeText "notes" ''
+                ## Supported Nix Versions
+                ${lib.concatStringsSep "\n" (
+                  map (v: "* ${v}") (lib.reverseList (lib.attrNames nixArchives))
+                )}
+              ''}"
+          fi
+        '';
+      };
+    }
+  );
+}

nix-quick-install.sh

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+#!/usr/bin/env bash
+
+set -x
+
+set -eu
+set -o pipefail
+
+# Create user-writeable /nix
+sudo install -d -o "$USER" /nix
+
+# Fetch and unpack nix
+sys="x86_64-linux" # TODO auto detect
+rel="$(cat "$RELEASE_FILE")"
+url="${NIX_ARCHIVES_URL:-https://github.com/nixbuild/nix-quick-install-action/releases/download/$rel}/nix-$NIX_VERSION-$sys.tar.zstd"
+
+curl -sL --retry 3 --retry-connrefused "$url" | zstdcat | \
+  tar --no-overwrite-dir -xC /
+
+# Setup nix.conf
+if [ -n "$NIX_CONF" ]; then
+  NIX_CONF_FILE="$(mktemp --tmpdir XXXX_nix.conf)"
+  NIX_USER_CONF_FILES="$NIX_CONF_FILE${NIX_USER_CONF_FILES:+:}${NIX_USER_CONF_FILES:-}"
+  echo "$NIX_CONF" > "$NIX_CONF_FILE"
+  echo "::set-env name=NIX_USER_CONF_FILES::$NIX_USER_CONF_FILES"
+fi
+
+# Set PATH
+echo "::add-path::/nix/bin"