action.yml

name: Set up Nix
description: >
  Nix with the PiFinder binary cache (cache.pifinder.io). Every workflow uses
  this action, so all jobs get the same Nix settings and the same cache.
inputs:
  attic-token:
    description: Token that lets the job push to the cache. Empty means pull only.
    required: false
    default: ""
  self-hosted:
    description: '"true" on a self-hosted runner, which already has Nix installed.'
    required: false
    default: "false"
runs:
  using: composite
  steps:
    - if: inputs.self-hosted != 'true'
      uses: DeterminateSystems/nix-installer-action@main
      with:
        determinate: false
        extra-conf: |
          extra-system-features = big-parallel
          extra-substituters = https://cache.pifinder.io/pifinder
          extra-trusted-public-keys = pifinder:8UU/O3oLkaJHHUyqEcPGl+9F1m4MqDca39Ewl49jBmE=

    - if: inputs.self-hosted == 'true'
      shell: bash
      run: |
        echo "/nix/var/nix/profiles/default/bin" >> "$GITHUB_PATH"
        echo "$HOME/.nix-profile/bin" >> "$GITHUB_PATH"

    - name: Attic login
      shell: bash
      env:
        ATTIC_TOKEN: ${{ inputs.attic-token }}
      run: |
        if [ -z "$ATTIC_TOKEN" ]; then
          echo "No Attic token: the job pulls from the cache but does not push"
          exit 0
        fi
        export PATH="/nix/var/nix/profiles/default/bin:$HOME/.nix-profile/bin:$PATH"
        nix profile install nixpkgs#attic-client
        attic login pifinder https://cache.pifinder.io "$ATTIC_TOKEN"
        attic use pifinder:pifinder