Fix flakes example and add a test

idempotent installation

.github/dependabot.yml

@@ -0,0 +1,13 @@
+version: 2
+updates:
+
+- package-ecosystem: github-actions
+  directory: "/"
+  schedule:
+    interval: daily
+    time: '00:00'
+    timezone: UTC
+  open-pull-requests-limit: 10
+  commit-message:
+      prefix: "chore"
+      include: "scope"

.github/workflows/test.yml

@@ -2,6 +2,8 @@ name: "install-nix-action test"
 on:
   pull_request:
   push:
+    branches:
+      - master
 
 jobs:
   simple-build:
@@ -15,28 +17,14 @@ jobs:
     - run: yarn build
     - name: Install Nix
       uses: ./
+      with:
+        nix_path: nixpkgs=channel:nixos-20.03
     - run: nix-env -iA cachix -f https://cachix.org/api/v1/install
     - run: cat /etc/nix/nix.conf
     # cachix should be available and be able to configure a cache
     - run: cachix use cachix
     - run: nix-build test.nix
 
-  no-channel:
-    strategy:
-      matrix:
-        os: [ubuntu-latest, macos-latest]
-    runs-on: ${{ matrix.os }}
-    steps:
-    - uses: actions/checkout@v2
-    - run: yarn install --frozen-lockfile
-    - run: yarn build
-    - name: Install Nix
-      uses: ./
-      with:
-        skip_adding_nixpkgs_channel: true
-    - run: nix-build test.nix && exit 1 || echo "OK"
-    - run: NIX_PATH=nixpkgs=https://github.com/NixOS/nixpkgs/tarball/ab5863afada3c1b50fc43bf774b75ea71b287cde nix-build test.nix
-
   custom-nix-path:
     strategy:
       matrix:
@@ -52,3 +40,41 @@ jobs:
         nix_path: nixpkgs=channel:nixos-20.03
     - run: test $NIX_PATH == "nixpkgs=channel:nixos-20.03"
     - run: nix-build test.nix
+
+  extra-nix-config:
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+    - uses: actions/checkout@v2
+    - run: yarn install --frozen-lockfile
+    - run: yarn build
+    - name: Install Nix
+      uses: ./
+      with: 
+        nix_path: nixpkgs=channel:nixos-20.03
+        extra_nix_config: |
+          sandbox = relaxed
+    - run: cat /etc/nix/nix.conf
+    - run: nix-build test.nix --arg noChroot true
+
+  flakes:
+    strategy:
+      matrix:
+        os: [ubuntu-latest, macos-latest]
+    runs-on: ${{ matrix.os }}
+    steps:
+    - uses: actions/checkout@v2
+      with:
+        # Nix Flakes doesn't work on shallow clones
+        fetch-depth: 0
+    - run: yarn install --frozen-lockfile
+    - run: yarn build
+    - name: Install Nix
+      uses: ./
+      with:
+        install_url: https://github.com/numtide/nix-flakes-installer/releases/download/nix-2.4pre20201221_9fab14a/install
+        extra_nix_config: |
+          experimental-features = nix-command flakes
+    - run: nix flake show github:NixOS/nixpkgs

README.md

@@ -4,6 +4,20 @@
 
 Installs [Nix](https://nixos.org/nix/) on GitHub Actions for the supported platforms: Linux and macOS.
 
+By default it has no nixpkgs configured, you have to set `nix_path`
+by [picking a channel](https://status.nixos.org/)
+or [pin nixpkgs yourself](https://nix.dev/reference/pinning-nixpkgs.html) 
+(see also [pinning tutorial](https://nix.dev/tutorials/towards-reproducibility-pinning-nixpkgs.html)).
+
+# Features
+
+- Quick installation (~4s on Linux, ~20s on macOS)
+- Multi-User installation (with sandboxing enabled only on Linux)
+- [Self-hosted github runner](https://docs.github.com/en/actions/hosting-your-own-runners/about-self-hosted-runners) support
+- Allows specifying Nix installation URL via `install_url`
+- Allows specifying extra Nix configration options via `extra_nix_config`
+- Allows specifying `$NIX_PATH` and channels via `nix_path`
+
 ## Usage
 
 Create `.github/workflows/test.yml` in your repo with the following contents:
@@ -18,7 +32,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
-    - uses: cachix/install-nix-action@v9
+    - uses: cachix/install-nix-action@v11
       with:
         nix_path: nixpkgs=channel:nixos-unstable
     - run: nix-build
@@ -28,16 +42,50 @@ See also [cachix-action](https://github.com/cachix/cachix-action) for
 simple binary cache setup to speed up your builds and share binaries
 with developers.
 
-## Options `with: ...`
+## Usage with Flakes
 
-- `install_url`: specify URL to install Nix from (mostly useful for testing non-stable releases)
+```yaml
+name: "Test"
+on:
+  pull_request:
+  push:
+jobs:
+  tests:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+      with:
+          # Nix Flakes doesn't work on shallow clones
+          fetch-depth: 0
+    - uses: cachix/install-nix-action@v11
+      with:
+        install_url: https://github.com/numtide/nix-flakes-installer/releases/download/nix-3.0pre20201007_5257a25/install
+        extra_nix_config: |
+          experimental-features = nix-command flakes
+    - run: nix-build
+```
 
-- `nix_path`: set `NIX_PATH` environment variable (if set `skip_adding_nixpkgs_channel` will be implicitly enabled)
+## Inputs (specify using `with:`)
 
-- `skip_adding_nixpkgs_channel`: set to `true` to skip adding nixpkgs-unstable channel (and save ~5s for each job build)
+- `install_url`: specify URL to install Nix from (useful for testing non-stable releases or pinning Nix for example https://releases.nixos.org/nix/nix-2.3.7/install)
+
+- `nix_path`: set `NIX_PATH` environment variable, for example `nixpkgs=channel:nixos-unstable`
+
+- `extra_nix_config`: append to `/etc/nix/nix.conf`
 
 ---
 
+## FAQ
+
+### Is it possible to run NixOS tests / Qemu+KVM with GitHub Actions?
+
+[Currently GitHub Actions are not running on Azure instance types that support nested virtualization](https://github.com/actions/virtual-environments/issues/183#issuecomment-610723516).
+
+### How do I print nixpkgs version with the channel I have configured?
+
+
+```nix-instantiate --eval -E '(import <nixpkgs> {}).lib.version'```
+
 ## Hacking
 
 Install the dependencies

action.yml

@@ -5,9 +5,9 @@ inputs:
   install_url:
     description: 'Installation URL that will contain a script to install Nix'
   nix_path:
-    description: 'Set NIX_PATH environment variable. If set "skip_adding_nixpkgs_channel" will be implicitly enabled'
-  skip_adding_nixpkgs_channel:
-    description: 'Skip adding nixpkgs-unstable channel'
+    description: 'Set NIX_PATH environment variable.'
+  extra_nix_config:
+    description: 'gets appended to `/etc/nix/nix.conf` if passed.'
 branding:
   color: 'blue'
   icon: 'sun'

lib/install-nix.sh

@@ -1,20 +1,38 @@
 #!/usr/bin/env bash
 set -euo pipefail
 
-# Set jobs to number of cores
-sudo sh -c 'echo max-jobs = auto >> /tmp/nix.conf'
-# Allow binary caches for runner user
-sudo sh -c 'echo trusted-users = root runner >> /tmp/nix.conf'
-
-if [[ $INPUT_SKIP_ADDING_NIXPKGS_CHANNEL = "true" || $INPUT_NIX_PATH != "" ]]; then
-  extra_cmd=--no-channel-add
-else
-  extra_cmd=
-  INPUT_NIX_PATH="/nix/var/nix/profiles/per-user/root/channels"
+if type -p nix &>/dev/null ; then
+  echo "Aborting: Nix is already installed at $(type -p nix)"
+  exit
 fi
 
-sh <(curl -L ${INPUT_INSTALL_URL:-https://nixos.org/nix/install}) \
-  --daemon --daemon-user-count 4 --nix-extra-conf-file /tmp/nix.conf --darwin-use-unencrypted-nix-store-volume $extra_cmd
+# Configure Nix
+add_config() {
+  echo "$1" | sudo tee -a /tmp/nix.conf >/dev/null
+}
+# Set jobs to number of cores
+add_config "max-jobs = auto"
+# Allow binary caches for user
+add_config "trusted-users = root $USER"
+# Append extra nix configuration if provided
+if [[ $INPUT_EXTRA_NIX_CONFIG != "" ]]; then
+  add_config "$INPUT_EXTRA_NIX_CONFIG"
+fi
+
+# Nix installer flags
+installer_options=(
+  --daemon
+  --daemon-user-count 4
+  --no-channel-add
+  --darwin-use-unencrypted-nix-store-volume
+  --nix-extra-conf-file /tmp/nix.conf
+)
+
+# On self-hosted runners we don't need to install more than once
+if [[ ! -d /nix/store ]] 
+then 
+  sh <(curl --retry 5 --retry-connrefused -L "${INPUT_INSTALL_URL:-https://nixos.org/nix/install}") "${installer_options[@]}"
+fi
 
 if [[ $OSTYPE =~ darwin ]]; then
   # Disable spotlight indexing of /nix to speed up performance
@@ -22,15 +40,15 @@ if [[ $OSTYPE =~ darwin ]]; then
 
   # macOS needs certificates hints
   cert_file=/nix/var/nix/profiles/default/etc/ssl/certs/ca-bundle.crt
-  echo "::set-env name=NIX_SSL_CERT_FILE::$cert_file"
+  echo "NIX_SSL_CERT_FILE=$cert_file" >> $GITHUB_ENV
   export NIX_SSL_CERT_FILE=$cert_file
   sudo launchctl setenv NIX_SSL_CERT_FILE "$cert_file"
 fi
 
 # Set paths
-echo "::add-path::/nix/var/nix/profiles/per-user/runner/profile/bin"
-echo "::add-path::/nix/var/nix/profiles/default/bin"
+echo "/nix/var/nix/profiles/per-user/$USER/profile/bin" >> $GITHUB_PATH
+echo "/nix/var/nix/profiles/default/bin" >> $GITHUB_PATH
 
 if [[ $INPUT_NIX_PATH != "" ]]; then
-  echo "::set-env name=NIX_PATH::${INPUT_NIX_PATH}"
+  echo "NIX_PATH=${INPUT_NIX_PATH}" >> $GITHUB_ENV
 fi

package.json

@@ -20,7 +20,7 @@
   "author": "Domen Kožar",
   "license": "ASL2",
   "dependencies": {
-    "@actions/core": "^1.1.0",
+    "@actions/core": "^1.2.6",
     "@actions/exec": "^1.0.1",
     "@actions/tool-cache": "^1.1.2"
   },

test.nix

@@ -2,12 +2,15 @@
 { size ? 1 # MB
 , num ? 10 # count 
 , currentTime ? builtins.currentTime
+, noChroot ? false
 }:
 
 with import <nixpkgs> {};
 
 let
-  drv = i: runCommand "${toString currentTime}-${toString i}" {} ''
+  drv = i: runCommand "${toString currentTime}-${toString i}" {
+    __noChroot = noChroot;
+  } ''
     dd if=/dev/zero of=$out bs=${toString size}MB count=1
   '';
 in writeText "empty-${toString num}-${toString size}MB" ''

yarn.lock

@@ -2,10 +2,10 @@
 # yarn lockfile v1
 
 
-"@actions/core@^1.1.0":
-  version "1.1.1"
-  resolved "https://registry.yarnpkg.com/@actions/core/-/core-1.1.1.tgz#e08f3dbfe04721bb3d040f8fca2d6d7e1817b2e1"
-  integrity sha512-O5G6EmlzTVsng7VSpNtszIoQq6kOgMGNTFB/hmwKNNA4V71JyxImCIrL27vVHCt2Cb3ImkaCr6o27C2MV9Ylwg==
+"@actions/core@^1.1.0", "@actions/core@^1.2.6":
+  version "1.2.6"
+  resolved "https://registry.yarnpkg.com/@actions/core/-/core-1.2.6.tgz#a78d49f41a4def18e88ce47c2cac615d5694bf09"
+  integrity sha512-ZQYitnqiyBc3D+k7LsgSBmMDVkOVidaagDG7j3fOym77jNunWRuYx7VSHa9GNfFZh+zh61xsCjRj4JxMZlDqTA==
 
 "@actions/exec@^1.0.1":
   version "1.0.1"
@@ -803,11 +803,6 @@ combined-stream@^1.0.6, combined-stream@~1.0.6:
   dependencies:
     delayed-stream "~1.0.0"
 
-commander@~2.20.0:
-  version "2.20.1"
-  resolved "https://registry.yarnpkg.com/commander/-/commander-2.20.1.tgz#3863ce3ca92d0831dcf2a102f5fb4b5926afd0f9"
-  integrity sha512-cCuLsMhJeWQ/ZpsFTbE765kvVfoeSddc4nU3up4fV+fDBcfUXnbITJ+JzhkdjzOqhURjZgujxaioam4RM9yGUg==
-
 component-emitter@^1.2.1:
   version "1.3.0"
   resolved "https://registry.yarnpkg.com/component-emitter/-/component-emitter-1.3.0.tgz#16e4070fba8ae29b679f2215853ee181ab2eabc0"
@@ -1318,13 +1313,14 @@ growly@^1.3.0:
   integrity sha1-8QdIy+dq+WS3yWyTxrzCivEgwIE=
 
 handlebars@^4.1.2:
-  version "4.4.0"
-  resolved "https://registry.yarnpkg.com/handlebars/-/handlebars-4.4.0.tgz#22e1a897c5d83023d39801f35f6b65cf97ed8b25"
-  integrity sha512-xkRtOt3/3DzTKMOt3xahj2M/EqNhY988T+imYSlMgs5fVhLN2fmKVVj0LtEGmb+3UUYV5Qmm1052Mm3dIQxOvw==
+  version "4.7.6"
+  resolved "https://registry.yarnpkg.com/handlebars/-/handlebars-4.7.6.tgz#d4c05c1baf90e9945f77aa68a7a219aa4a7df74e"
+  integrity sha512-1f2BACcBfiwAfStCKZNrUCgqNZkGsAT7UM3kkYtXuLo0KnaVfjKOyf7PRzB6++aK9STyT1Pd2ZCPe3EGOXleXA==
   dependencies:
+    minimist "^1.2.5"
     neo-async "^2.6.0"
-    optimist "^0.6.1"
     source-map "^0.6.1"
+    wordwrap "^1.0.0"
   optionalDependencies:
     uglify-js "^3.1.4"
 
@@ -2225,9 +2221,9 @@ lodash.sortby@^4.7.0:
   integrity sha1-7dFMgk4sycHgsKG0K7UhBRakJDg=
 
 lodash@^4.17.11, lodash@^4.17.13:
-  version "4.17.15"
-  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.15.tgz#b447f6670a0455bbfeedd11392eff330ea097548"
-  integrity sha512-8xOcRHvCjnocdS5cpwXQXVzmmh5e5+saE2QGoeQmbKmRS6J3VQppPOIt0MnmE+4xlZoumy0GPG0D0MVIQbNA1A==
+  version "4.17.19"
+  resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.19.tgz#e48ddedbe30b3321783c5b4301fbd353bc1e4a4b"
+  integrity sha512-JNvd8XER9GQX0v2qJgsaN/mzFCNA5BRe/j8JN9d+tWyGLSodKQHKFicdwNYzWwI3wjRnaKPsGj1XkBjx/F96DQ==
 
 loose-envify@^1.0.0:
   version "1.4.0"
@@ -2316,15 +2312,10 @@ minimist@0.0.8:
   resolved "https://registry.yarnpkg.com/minimist/-/minimist-0.0.8.tgz#857fcabfc3397d2625b8228262e86aa7a011b05d"
   integrity sha1-hX/Kv8M5fSYluCKCYuhqp6ARsF0=
 
-minimist@^1.1.1, minimist@^1.2.0:
-  version "1.2.0"
-  resolved "https://registry.yarnpkg.com/minimist/-/minimist-1.2.0.tgz#a35008b20f41383eec1fb914f4cd5df79a264284"
-  integrity sha1-o1AIsg9BOD7sH7kU9M1d95omQoQ=
-
-minimist@~0.0.1:
-  version "0.0.10"
-  resolved "https://registry.yarnpkg.com/minimist/-/minimist-0.0.10.tgz#de3f98543dbf96082be48ad1a0c7cda836301dcf"
-  integrity sha1-3j+YVD2/lggr5IrRoMfNqDYwHc8=
+minimist@^1.1.1, minimist@^1.2.0, minimist@^1.2.5:
+  version "1.2.5"
+  resolved "https://registry.yarnpkg.com/minimist/-/minimist-1.2.5.tgz#67d66014b66a6a8aaa0c083c5fd58df4e4e97602"
+  integrity sha512-FM9nNUYrRBAELZQT3xeZQ7fmMOBg6nWNmJKTcgsJeaLstP/UODVpGsr5OhXhhXg6f+qtJ8uiZ+PUxkDWcgIXLw==
 
 minipass@^2.6.0, minipass@^2.8.6:
   version "2.8.6"
@@ -2411,9 +2402,9 @@ needle@^2.2.1:
     sax "^1.2.4"
 
 neo-async@^2.6.0:
-  version "2.6.1"
-  resolved "https://registry.yarnpkg.com/neo-async/-/neo-async-2.6.1.tgz#ac27ada66167fa8849a6addd837f6b189ad2081c"
-  integrity sha512-iyam8fBuCUpWeKPGpaNMetEocMt364qkCsfL9JuhjXX6dRnguRVOfk2GZaDpPjcOKiiXCPINZC1GczQ7iTq3Zw==
+  version "2.6.2"
+  resolved "https://registry.yarnpkg.com/neo-async/-/neo-async-2.6.2.tgz#b4aafb93e3aeb2d8174ca53cf163ab7d7308305f"
+  integrity sha512-Yd3UES5mWCSqR+qNT93S3UoYUkqAZ9lLg8a7g9rimsWmYGK8cVToA4/sF3RrshdyV3sAGMXVUmpMYOw+dLpOuw==
 
 nice-try@^1.0.4:
   version "1.0.5"
@@ -2580,14 +2571,6 @@ once@^1.3.0, once@^1.3.1, once@^1.4.0:
   dependencies:
     wrappy "1"
 
-optimist@^0.6.1:
-  version "0.6.1"
-  resolved "https://registry.yarnpkg.com/optimist/-/optimist-0.6.1.tgz#da3ea74686fa21a19a111c326e90eb15a0196686"
-  integrity sha1-2j6nRob6IaGaERwybpDrFaAZZoY=
-  dependencies:
-    minimist "~0.0.1"
-    wordwrap "~0.0.2"
-
 optionator@^0.8.1:
   version "0.8.2"
   resolved "https://registry.yarnpkg.com/optionator/-/optionator-0.8.2.tgz#364c5e409d3f4d6301d6c0b4c05bba50180aeb64"
@@ -3459,12 +3442,9 @@ typescript@^3.5.1:
   integrity sha512-N7bceJL1CtRQ2RiG0AQME13ksR7DiuQh/QehubYcghzv20tnh+MQnQIuJddTmsbqYj+dztchykemz0zFzlvdQw==
 
 uglify-js@^3.1.4:
-  version "3.6.0"
-  resolved "https://registry.yarnpkg.com/uglify-js/-/uglify-js-3.6.0.tgz#704681345c53a8b2079fb6cec294b05ead242ff5"
-  integrity sha512-W+jrUHJr3DXKhrsS7NUVxn3zqMOFn0hL/Ei6v0anCIMoKC93TjcflTagwIHLW7SfMFfiQuktQyFVCFHGUE0+yg==
-  dependencies:
-    commander "~2.20.0"
-    source-map "~0.6.1"
+  version "3.10.4"
+  resolved "https://registry.yarnpkg.com/uglify-js/-/uglify-js-3.10.4.tgz#dd680f5687bc0d7a93b14a3482d16db6eba2bfbb"
+  integrity sha512-kBFT3U4Dcj4/pJ52vfjCSfyLyvG9VYYuGYPmrPvAxRw/i7xHiT4VvCev+uiEMcEEiu6UNB6KgWmGtSUYIWScbw==
 
 underscore@1.8.3:
   version "1.8.3"
@@ -3609,12 +3589,7 @@ wide-align@^1.1.0:
   dependencies:
     string-width "^1.0.2 || 2"
 
-wordwrap@~0.0.2:
-  version "0.0.3"
-  resolved "https://registry.yarnpkg.com/wordwrap/-/wordwrap-0.0.3.tgz#a3d5da6cd5c0bc0008d37234bbaf1bed63059107"
-  integrity sha1-o9XabNXAvAAI03I0u68b7WMFkQc=
-
-wordwrap@~1.0.0:
+wordwrap@^1.0.0, wordwrap@~1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/wordwrap/-/wordwrap-1.0.0.tgz#27584810891456a4171c8d0226441ade90cbcaeb"
   integrity sha1-J1hIEIkUVqQXHI0CJkQa3pDLyus=