nixos-config/.github/workflows/automate-update.yml

name: "Automated flake inputs update"
on:
  schedule:
    # Every week on Friday.
    - cron: '0 * * * 5'
jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v3
      - uses: cachix/install-nix-action@v16
        with:
          nix_path: nixpkgs=channel:nixos-unstable
      - name: Update flake inputs
        run: |
          nix shell nixpkgs#git

          # This is set by the GitHub Actions bot just to make identifying which commits are automated.
          git config user.name 'github-actions[bot]'
          git config user.email 'github-actions[bot]@users.noreply.github.com'

          nix flake update --commit-lock-file \
            --commit-lockfile-summary 'flake.lock: update-inputs'
      - name: Build custom packages
        run: nix shell nixpkgs#nix-build-uncached --command nix-build-uncached ./pkgs
      - name: Build NixOS configurations
        run: nix build .#nixosConfigurations.ni.config.system.build.toplevel
      - name: Push updates to remote
        run: |
          git remote remove origin
          git remote add origin https://${{ secrets.GITHUB_TOKEN }}@github.com/foo-dogsquared/nixos-config.git
          git push --set-upstream origin master --tags