name: better-setup-docker
description: Install the pinned static docker CLI when missing and verify the runner's daemon socket works — for runners that mount the host docker socket.
inputs:
  docker-version:
    description: Exact docker CLI version to install when missing (x.y.z).
    default: "27.5.1"
  verify-socket:
    description: Run `docker info` to prove the daemon socket is reachable ("true"/"false").
    default: "true"
runs:
  using: composite
  steps:
    - shell: bash
      run: |
        set -euo pipefail
        v="${{ inputs.docker-version }}"
        if ! command -v docker >/dev/null 2>&1; then
          case "$(uname -m)" in
            x86_64|amd64) arch=x86_64 ;;
            aarch64|arm64) arch=aarch64 ;;
            *) echo "better-setup-docker: unsupported arch $(uname -m)" >&2; exit 1 ;;
          esac
          curl -fsSL "https://download.docker.com/linux/static/stable/${arch}/docker-${v}.tgz" | tar -xz -C /tmp docker
          mv /tmp/docker/docker /usr/local/bin/docker
        fi
        docker --version
        if [ "${{ inputs.verify-socket }}" = "true" ]; then
          docker info >/dev/null && echo "docker ok (host socket)"
        fi