FlakeHub now supports Semaphore CI

version: v1.0
name: Push store paths to FlakeHub Cache and publish flake release on FlakeHub
agent:
  machine:
    type: f1-standard-4
    os_image: ubuntu2404
blocks:
73 collapsed lines
  - name:
    dependencies: []
    task:
      prologue:
        commands:
          # Get the latest version of the repository's source code from GitHub
          - checkout

      jobs:
        - name: Publish flake and cache package
          commands:
          # The flake's repository
          - export FLAKEHUB_PUSH_REPOSITORY="$(echo "${SEMAPHORE_ORGANIZATION_URL}" | cut -d "." -f1 | cut -d '/' -f3)/${SEMAPHORE_PROJECT_NAME}"

          # Environment variables for Magic Nix Cache, which automatically pushes Nix artifacts to FlakeHub Cache
          - export MAGIC_NIX_CACHE_CLOSURE_URL="https://install.determinate.systems/magic-nix-cache-closure/branch/main/X64-Linux?ci=semaphore"
          - export MNC_LISTEN="127.0.0.1:37515"

          # Install Determinate Nix and start the Nix daemon
          - curl --proto '=https' --tlsv1.2 -sSf -L https://install.determinate.systems/nix | sh -s -- install linux --determinate --no-confirm --init systemd
          - . /nix/var/nix/profiles/default/etc/profile.d/nix-daemon.sh

          # Log in using the `determinate-nixd login` command (used by magic-nix-cache, substitutions)
          - echo "${SEMAPHORE_OIDC_TOKEN}" | determinate-nixd login token --token-file /dev/stdin

          # Acquire the `flakehub-push` executable
          - curl -L "${FLAKEHUB_PUSH_BINARY_URL}" | sudo tee /usr/bin/flakehub-push &>/dev/null
          - sudo chmod +x /usr/bin/flakehub-push

          # Acquire the `magic-nix-cache` executable
          - export MNC_CLSR="$(curl -L "${MAGIC_NIX_CACHE_CLOSURE_URL}" | xz -d | sudo "$(which nix-store)" --import | tail -n1 | head -n1)"
          - sudo ln -sf "${MNC_CLSR}/bin/magic-nix-cache" /usr/bin/magic-nix-cache
          - magic-nix-cache --help

          # Stage login credentials for `flakehub-push`
          - export FLAKEHUB_PUSH_OIDC_TOKEN="${SEMAPHORE_OIDC_TOKEN}"

          # Start Magic Nix Cache
          - export MNC_STARTUP_FILE="/tmp/mnc-startup"
          - nohup magic-nix-cache --listen "${MNC_LISTEN}" --startup-notification-file "${MNC_STARTUP_FILE}" &>/tmp/mnc.log &
          - |
              (
              STARTED=0
              for n in {1..6}; do
                if [ -e "${MNC_STARTUP_FILE}" ]; then
                  echo "magic-nix-cache daemon has successfully started up after ${n} attempt(s)"
                  STARTED=1
                  break
                else
                  echo "waiting on magic-nix-cache daemon; on attempt ${n}"
                  sleep 2
                fi
              done
              if [[ "${STARTED}" != "1" ]]; then
                echo "The daemon did not start up within 60 seconds; exiting"
                exit 1
              fi
              ) || true

          # Build a package output by the repository's Nix flake
          - nix build ".#packages.x86_64-linux.default"

          # Publish a flake release to FlakeHub if and only if it's a tag reference
          - |
            if [[ "${SEMAPHORE_GIT_REF_TYPE}" == "tag" ]]; then
              flakehub-push \
                --tag "$(cat "${SEMAPHORE_GIT_REF}" | cut -d '/' -f2)" \
                --visibility private \
                --include-output-paths
            fi

          # Stop Magic Nix Cache
          - curl -XPOST "http://${MNC_LISTEN}/api/workflow-finish"