Resilient installation

.github/workflows/test.yml

@@ -12,7 +12,7 @@ jobs:
         os: [ubuntu-latest, macos-latest]
     runs-on: ${{ matrix.os }}
     steps:
-    - uses: actions/checkout@v2.4.0
+    - uses: actions/checkout@v2.3.5
     - run: yarn install --frozen-lockfile
     - run: yarn build
     - name: Install Nix
@@ -31,7 +31,7 @@ jobs:
         os: [ubuntu-latest, macos-latest]
     runs-on: ${{ matrix.os }}
     steps:
-    - uses: actions/checkout@v2.4.0
+    - uses: actions/checkout@v2.3.5
     - run: yarn install --frozen-lockfile
     - run: yarn build
     - name: Install Nix
@@ -47,7 +47,7 @@ jobs:
         os: [ubuntu-latest, macos-latest]
     runs-on: ${{ matrix.os }}
     steps:
-    - uses: actions/checkout@v2.4.0
+    - uses: actions/checkout@v2.3.5
     - run: yarn install --frozen-lockfile
     - run: yarn build
     - name: Install Nix
@@ -65,7 +65,7 @@ jobs:
         os: [ubuntu-latest, macos-latest]
     runs-on: ${{ matrix.os }}
     steps:
-    - uses: actions/checkout@v2.4.0
+    - uses: actions/checkout@v2.3.5
     - run: yarn install --frozen-lockfile
     - run: yarn build
     - name: Install Nix
@@ -74,6 +74,7 @@ jobs:
         install_url: https://nixos-nix-install-tests.cachix.org/serve/i6laym9jw3wg9mw6ncyrk6gjx4l34vvx/install
         install_options: '--tarball-url-prefix https://nixos-nix-install-tests.cachix.org/serve'
         extra_nix_config: |
+          experimental-features = nix-command flakes
           access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
     - run: nix flake show github:NixOS/nixpkgs
 
@@ -83,7 +84,7 @@ jobs:
         os: [ubuntu-latest, macos-latest]
     runs-on: ${{ matrix.os }}
     steps:
-    - uses: actions/checkout@v2.4.0
+    - uses: actions/checkout@v2.3.5
     - run: yarn install --frozen-lockfile
     - run: yarn build
     - name: Install Nix
@@ -93,19 +94,3 @@ jobs:
         install_url: https://nixos-nix-install-tests.cachix.org/serve/i6laym9jw3wg9mw6ncyrk6gjx4l34vvx/install
         install_options: '--tarball-url-prefix https://nixos-nix-install-tests.cachix.org/serve'
     - run: nix-build test.nix
-
-  oldest-supported-installer:
-    strategy:
-        matrix:
-          os: [ubuntu-latest, macos-latest]
-    runs-on: ${{ matrix.os }}
-    steps:
-    - uses: actions/checkout@v2.3.5
-    - run: yarn install --frozen-lockfile
-    - run: yarn build
-    - name: Install Nix
-      uses: ./
-      with:
-        nix_path: nixpkgs=channel:nixos-21.05
-        install_url: https://releases.nixos.org/nix/nix-2.3.5/install
-    - run: nix-build test.nix

README.md

@@ -18,7 +18,6 @@ or [pin nixpkgs yourself](https://nix.dev/reference/pinning-nixpkgs.html)
 - Allows specifying extra Nix configration options via `extra_nix_config`
 - Allows specifying `$NIX_PATH` and channels via `nix_path`
 - Share `/nix/store` between builds using [cachix-action](https://github.com/cachix/cachix-action) for simple binary cache setup to speed up your builds and share binaries with your team
-- Enables `flakes` and `nix-command` experimental features by default (to disable, set ``experimental-features` via `extra_nix_config`) 
 
 ## Usage
 
@@ -34,7 +33,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2.3.4
-    - uses: cachix/install-nix-action@v14.1
+    - uses: cachix/install-nix-action@v13
       with:
         nix_path: nixpkgs=channel:nixos-unstable
     - run: nix-build
@@ -53,11 +52,12 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2.3.4
-    - uses: cachix/install-nix-action@v14.1
+    - uses: cachix/install-nix-action@v14
       with:
         install_url: https://nixos-nix-install-tests.cachix.org/serve/vij683ly7sl95nnhb67bdjjfabclr85m/install
         install_options: '--tarball-url-prefix https://nixos-nix-install-tests.cachix.org/serve'
         extra_nix_config: |
+          experimental-features = nix-command flakes
           access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
     - run: nix build
     - run: nix flake check

lib/install-nix.sh

@@ -18,9 +18,6 @@ add_config "trusted-users = root $USER"
 if [[ $INPUT_EXTRA_NIX_CONFIG != "" ]]; then
   add_config "$INPUT_EXTRA_NIX_CONFIG"
 fi
-if [[ ! $INPUT_EXTRA_NIX_CONFIG =~ "experimental-features" ]]; then  
-  add_config "experimental-features = nix-command flakes"
-fi
 
 # Nix installer flags
 installer_options=(
@@ -38,7 +35,8 @@ if [[ $OSTYPE =~ darwin || -e /run/systemd/system ]]; then
 else
   # "fix" the following error when running nix*
   # error: the group 'nixbld' specified in 'build-users-group' does not exist
-  add_config "build-users-group ="
+  mkdir -m 0755 /etc/nix
+  echo "build-users-group =" > /etc/nix/nix.conf
 fi
 
 if [[ $INPUT_INSTALL_OPTIONS != "" ]]; then
@@ -47,7 +45,15 @@ if [[ $INPUT_INSTALL_OPTIONS != "" ]]; then
 fi
 
 echo "installer options: ${installer_options[@]}"
-sh <(curl --retry 5 --retry-connrefused -L "${INPUT_INSTALL_URL:-https://nixos.org/nix/install}") "${installer_options[@]}"
+
+# There is --retry-on-errors, but only newer curl versions support that
+until curl -o /tmp/install -v --fail --retry 5 --retry-connrefused -L "${INPUT_INSTALL_URL:-https://nixos.org/nix/install}" 
+do
+  sleep 1
+done
+
+chmod +x /tmp/install
+sh /tmp/install "${installer_options[@]}"
 
 if [[ $OSTYPE =~ darwin ]]; then
   # macOS needs certificates hints