.gitlab-ci.yml

# This file expects two variables: `NIX_CI_CACHE_PUB_KEY` and `NIX_CI_CACHE_PRIV_KEY`
# Those variables can be generated with: `nix-store --generate-binary-cache-key ci_nix_store priv.pem pub.pem`

stages: [ nix-cache, lint, build, tests ]

variables:
  DEPENDENCIES: ".#theories.inputDerivation .#frontend.inputDerivation .#frontend.cargoArtifacts nixpkgs#gnumake nixpkgs#gnupatch nixpkgs#gnused"
  NIX_STORE_ARTIFACTS_PATH: ".ci_nix_artifacts"
  NIX_STORE_CACHE_PATH: ".ci_nix_cache"

default:
  image: nixos/nix:2.21.2
  interruptible: true
  tags: [ fp ]

  before_script:
   - echo "experimental-features = nix-command flakes" >> /etc/nix/nix.conf
   - echo "substituters = file://$(pwd)/${NIX_STORE_ARTIFACTS_PATH} file://$(pwd)/${NIX_STORE_CACHE_PATH} https://cache.nixos.org" >> /etc/nix/nix.conf
   - echo "trusted-public-keys = ${NIX_CI_CACHE_PUB_KEY} cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY=" >> /etc/nix/nix.conf

   # Since the cache is not guaranteed to be available, it is preferable to build the dependencies for each job (which is no-op if the cache is available)
   - nix build --print-build-logs ${DEPENDENCIES}

  cache: &nix_cache
    key:
      files: [ flake.lock, flake.nix ]
    paths: [ "${NIX_STORE_CACHE_PATH}" ]
    policy: pull


.build_to_cache:
  cache:
    <<: *nix_cache
    policy: pull-push

  script:
   - nix build --print-build-logs ${NIX_DERIVATION}
   - nix store sign --key-file <(echo "${NIX_CI_CACHE_PRIV_KEY}") --recursive ${NIX_DERIVATION}
   - nix copy --to "file://$(pwd)/${NIX_STORE_CACHE_PATH}" ${NIX_DERIVATION}

.build_to_artifacts:
  artifacts:
    paths: [ "${NIX_STORE_ARTIFACTS_PATH}" ]
    when: always

  script:
   - !reference [ .build_to_cache, script ]

   # To avoid generating large `artifacts` without cluttering the `cache`, an overlay on top of the nix store must be used.
   # So, one of the following solutions can be used:
   #  1. Using the `local-overlay` feature, but still in RFC (https://github.com/NixOS/rfcs/pull/152)
   #  2. Using OverlayFS, but SYS_ADMIN capability is required
   #  3. Moving files around, which is not the best way to do
   - mkdir -p "${NIX_STORE_ARTIFACTS_PATH}/nar"
   - nix path-info ${NIX_DERIVATION} | xargs -r basename -a | cut -d'-' -f1 | xargs -r printf -- "${NIX_STORE_CACHE_PATH}/%s.narinfo\0" | xargs -r0 mv -v -t "${NIX_STORE_ARTIFACTS_PATH}" || true
   - find "${NIX_STORE_ARTIFACTS_PATH}" -name "*.narinfo" -type f -print0 | xargs -r0 grep -oPh "(?<=URL:\ ).*" | xargs -r printf -- "${NIX_STORE_CACHE_PATH}/%s\0" | xargs -r0 mv -v -t ${NIX_STORE_ARTIFACTS_PATH}/nar || true


nix-cache:
  stage: nix-cache
  variables:
    NIX_DERIVATION: ${DEPENDENCIES}
  extends: .build_to_cache

clippy:
  stage: lint
  needs: [ "nix-cache" ]
  script:
   - cd rr_frontend
   - nix develop -c cargo clippy --all-targets --all-features --no-deps