caddy Caddy reverse proxy + HTTPS

#!/usr/bin/env bash
# Served by xyz.sh/caddy
# Human-readable page: https://xyz.sh/caddy
# This file is the common library followed by the script body.
# No telemetry is added by xyz.sh.
# =============================================================================
# xyz.sh common library
# Shared helpers for every script served by xyz.sh.
#
# Promises:
#   - No telemetry, analytics, or background "phone-home" calls
#   - No hidden installs or config changes beyond what the script announces
#   - Official upstream URLs are printed before any remote code is executed
#   - Destructive or system-changing steps ask for confirmation (or YES=1 / -y)
# =============================================================================

if [[ -n "${XYZ_COMMON_LOADED:-}" ]]; then
  # When sourced a second time, return. When executed as a file, return fails.
  # shellcheck disable=SC2317
  return 0 2>/dev/null || true
fi
# shellcheck disable=SC2034
XYZ_COMMON_LOADED=1

set -euo pipefail

XYZ_VERSION="1.3.0"
XYZ_BASE="${XYZ_BASE:-https://xyz.sh}"
XYZ_NAME="${XYZ_NAME:-unknown}"

# --- language ---------------------------------------------------------------
# Override with XYZ_LANG=zh or XYZ_LANG=en.
if [[ -z "${XYZ_LANG:-}" ]]; then
  case "${LC_ALL:-${LC_MESSAGES:-${LANG:-}}}" in
    zh*|ZH*|cmn*|CMN*) XYZ_LANG="zh" ;;
    *) XYZ_LANG="en" ;;
  esac
fi

xyz_t() {
  # xyz_t "English text" "中文文本"
  if [[ "${XYZ_LANG}" == "zh" ]]; then
    printf '%s' "${2:-$1}"
  else
    printf '%s' "$1"
  fi
}

# --- colors (TTY only) ------------------------------------------------------
# XYZ_COLOR=always|never|auto (default auto: TTY and no NO_COLOR); --no-color.
_xyz_color=0
case "${XYZ_COLOR:-auto}" in
  always) _xyz_color=1 ;;
  never) _xyz_color=0 ;;
  *) [[ -t 1 && -z "${NO_COLOR:-}" ]] && _xyz_color=1 ;;
esac
[[ "${XYZ_NO_COLOR:-0}" == "1" ]] && _xyz_color=0
if [[ "${_xyz_color}" == "1" ]]; then
  XYZ_C_RESET=$'\033[0m'
  XYZ_C_BOLD=$'\033[1m'
  XYZ_C_DIM=$'\033[2m'
  XYZ_C_RED=$'\033[31m'
  XYZ_C_GREEN=$'\033[32m'
  XYZ_C_YELLOW=$'\033[33m'
  XYZ_C_CYAN=$'\033[36m'
else
  XYZ_C_RESET=""
  XYZ_C_BOLD=""
  XYZ_C_DIM=""
  XYZ_C_RED=""
  XYZ_C_GREEN=""
  XYZ_C_YELLOW=""
  XYZ_C_CYAN=""
fi

xyz_info()  { printf '%s[INFO]%s %s\n'  "${XYZ_C_GREEN}"  "${XYZ_C_RESET}" "$*"; }
xyz_warn()  { printf '%s[WARN]%s %s\n'  "${XYZ_C_YELLOW}" "${XYZ_C_RESET}" "$*" >&2; }
xyz_error() { printf '%s[ERROR]%s %s\n' "${XYZ_C_RED}"    "${XYZ_C_RESET}" "$*" >&2; }
xyz_step()  { printf '%s==>%s %s\n'     "${XYZ_C_CYAN}"   "${XYZ_C_RESET}" "$*"; }

# --- args / init ------------------------------------------------------------
XYZ_ARGS=()
XYZ_YES=0
XYZ_DRY_RUN=0

xyz_parse_global_args() {
  local filtered=()
  local arg
  for arg in "$@"; do
    case "${arg}" in
      -y|--yes)
        XYZ_YES=1
        ;;
      --lang=zh|zh)
        XYZ_LANG="zh"
        ;;
      --lang=en|en)
        XYZ_LANG="en"
        ;;
      --dry-run)
        XYZ_DRY_RUN=1
        ;;
      --no-color)
        XYZ_NO_COLOR=1
        XYZ_C_RESET=""; XYZ_C_BOLD=""; XYZ_C_DIM=""; XYZ_C_RED=""
        XYZ_C_GREEN=""; XYZ_C_YELLOW=""; XYZ_C_CYAN=""
        ;;
      --help|-h)
        XYZ_HELP=1
        filtered+=("${arg}")
        ;;
      *)
        filtered+=("${arg}")
        ;;
    esac
  done
  XYZ_ARGS=("${filtered[@]+"${filtered[@]}"}")
  if [[ "${YES:-}" =~ ^(1|yes|true|YES)$ || "${XYZ_ASSUME_YES:-}" == "1" ]]; then
    XYZ_YES=1
  fi
  # Exported so individual scripts can read flags set here.
  export XYZ_ARGS XYZ_YES XYZ_LANG XYZ_HELP="${XYZ_HELP:-}" XYZ_DRY_RUN="${XYZ_DRY_RUN:-0}"
  export XYZ_NO_COLOR="${XYZ_NO_COLOR:-0}"
  if declare -F xyz_ui_init >/dev/null; then xyz_ui_init; fi
}

xyz_banner() {
  local title="${XYZ_TITLE:-$XYZ_NAME}"
  printf '\n%s%sxyz.sh/%s%s  v%s\n' "${XYZ_C_BOLD}" "${XYZ_C_CYAN}" "${XYZ_NAME}" "${XYZ_C_RESET}" "${XYZ_VERSION}"
  printf '%s\n' "${XYZ_C_DIM}----------------------------------------${XYZ_C_RESET}"
  printf '  %s: %s/%s\n' "$(xyz_t "Page" "页面")" "${XYZ_BASE}" "${XYZ_NAME}"
  printf '  %s: %s/%s.sh\n' "$(xyz_t "Raw" "源码")" "${XYZ_BASE}" "${XYZ_NAME}"
  if [[ -n "${XYZ_UPSTREAM:-}" ]]; then
    printf '  %s: %s\n' "$(xyz_t "Upstream" "上游来源")" "${XYZ_UPSTREAM}"
  fi
  printf '  %s\n' "$(xyz_t "No telemetry, no hidden actions." "无遥测、无隐藏操作。")"
  printf '%s\n\n' "${XYZ_C_DIM}----------------------------------------${XYZ_C_RESET}"
  if [[ -n "${title}" && "${title}" != "${XYZ_NAME}" ]]; then
    xyz_step "${title}"
  fi
}

xyz_init() {
  xyz_parse_global_args "$@"
  xyz_detect_os
  xyz_banner
}

# --- root / OS --------------------------------------------------------------
xyz_is_root() {
  [[ "${EUID:-$(id -u)}" -eq 0 ]]
}

xyz_require_root() {
  if ! xyz_is_root; then
    xyz_error "$(xyz_t \
      "This script must be run as root. Try: sudo bash" \
      "请使用 root 运行。可尝试：sudo bash")"
    exit 1
  fi
}

xyz_prefer_root() {
  if ! xyz_is_root; then
    xyz_warn "$(xyz_t \
      "Not running as root; some information or tests may be limited." \
      "当前不是 root，部分信息或测试可能不完整。")"
  fi
}

XYZ_OS_ID=""
XYZ_OS_LIKE=""
XYZ_OS_VERSION=""
XYZ_OS_FAMILY=""   # debian | rhel | unknown
XYZ_OS_PRETTY=""

xyz_detect_os() {
  XYZ_OS_ID=""
  XYZ_OS_LIKE=""
  XYZ_OS_VERSION=""
  XYZ_OS_FAMILY="unknown"
  XYZ_OS_PRETTY="unknown"
  if [[ -r /etc/os-release ]]; then
    # shellcheck disable=SC1091
    . /etc/os-release
    XYZ_OS_ID="${ID:-}"
    XYZ_OS_LIKE="${ID_LIKE:-}"
    XYZ_OS_VERSION="${VERSION_ID:-}"
    XYZ_OS_PRETTY="${PRETTY_NAME:-$XYZ_OS_ID}"
    export XYZ_OS_ID XYZ_OS_LIKE XYZ_OS_VERSION XYZ_OS_FAMILY XYZ_OS_PRETTY
  fi
  case "${XYZ_OS_ID}" in
    debian|ubuntu)
      XYZ_OS_FAMILY="debian"
      ;;
    centos|rhel|rocky|almalinux|alma|fedora)
      XYZ_OS_FAMILY="rhel"
      ;;
    *)
      case " ${XYZ_OS_ID} ${XYZ_OS_LIKE} " in
        *debian*|*ubuntu*) XYZ_OS_FAMILY="debian" ;;
        *rhel*|*centos*|*fedora*|*rocky*|*alma*) XYZ_OS_FAMILY="rhel" ;;
        *) : ;;
      esac
      ;;
  esac
}

xyz_os_supported() {
  case "${XYZ_OS_ID}" in
    debian|ubuntu|centos|rocky|almalinux) return 0 ;;
    *) : ;;
  esac
  case " ${XYZ_OS_LIKE} " in
    *debian*|*ubuntu*|*rhel*|*centos*|*rocky*|*alma*) return 0 ;;
    *) : ;;
  esac
  return 1
}

xyz_require_supported_os() {
  xyz_detect_os
  if ! xyz_os_supported; then
    xyz_warn "$(xyz_t \
      "Unrecognized distribution: ${XYZ_OS_ID:-unknown} (${XYZ_OS_PRETTY}). Officially supported: Debian, Ubuntu, CentOS, Rocky, AlmaLinux." \
      "未能识别的发行版：${XYZ_OS_ID:-unknown}（${XYZ_OS_PRETTY}）。官方支持：Debian、Ubuntu、CentOS、Rocky、AlmaLinux。")"
    if ! xyz_confirm "$(xyz_t "Continue anyway?" "仍然继续？")"; then
      exit 1
    fi
  else
    xyz_info "$(xyz_t "Detected OS:" "检测到系统：") ${XYZ_OS_PRETTY} (${XYZ_OS_FAMILY})"
  fi
}

# --- packages / commands ----------------------------------------------------
xyz_need_cmd() {
  command -v "$1" >/dev/null 2>&1
}

xyz_pkg_install() {
  xyz_detect_os
  if (( $# == 0 )); then
    return 0
  fi
  case "${XYZ_OS_FAMILY}" in
    debian)
      export DEBIAN_FRONTEND=noninteractive
      apt-get update -y || xyz_warn "$(xyz_t "apt-get update reported errors (a repository may be unreachable); trying to install anyway." "apt-get update 报错（可能有软件源无法访问），仍尝试安装。")"
      apt-get install -y --no-install-recommends "$@"
      ;;
    rhel)
      if xyz_need_cmd dnf; then
        dnf install -y "$@"
      elif xyz_need_cmd yum; then
        yum install -y "$@"
      else
        xyz_error "$(xyz_t "Neither dnf nor yum is available." "找不到 dnf 或 yum。")"
        exit 1
      fi
      ;;
    *)
      xyz_error "$(xyz_t "Cannot install packages on this OS automatically." "无法在此系统上自动安装软件包。")"
      exit 1
      ;;
  esac
}

xyz_ensure_cmds() {
  local pkg
  local missing=()
  for pkg in "$@"; do
    if ! xyz_need_cmd "${pkg}"; then
      missing+=("${pkg}")
    fi
  done
  if ((${#missing[@]} > 0)); then
    xyz_info "$(xyz_t "Installing missing commands:" "正在安装缺失命令：") ${missing[*]}"
    xyz_pkg_install "${missing[@]}"
  fi
}

# --- confirmation (safe with curl | bash) -----------------------------------
# A readable /dev/tty node is not enough: in containers or curl|bash without a
# controlling terminal, open() fails with ENXIO ("No such device or address").
# [[ -r /dev/tty ]] is true in that case and must not be used as the check.
xyz_open_tty() {
  # Opens /dev/tty into XYZ_TTY_FD if it is a real terminal. Caller must close.
  local fd
  XYZ_TTY_FD=""
  # Brace group so a failed open cannot leak "No such device or address".
  if { exec {fd}<>/dev/tty; } 2>/dev/null && [[ -t "${fd}" ]]; then
    XYZ_TTY_FD="${fd}"
    return 0
  fi
  if [[ -n "${fd:-}" ]]; then
    exec {fd}>&- 2>/dev/null || true
  fi
  return 1
}

xyz_close_tty() {
  if [[ -n "${XYZ_TTY_FD:-}" ]]; then
    exec {XYZ_TTY_FD}>&- 2>/dev/null || true
    XYZ_TTY_FD=""
  fi
}

xyz_confirm() {
  local prompt="$1"
  if [[ "${XYZ_YES}" == "1" ]]; then
    xyz_info "$(xyz_t "Auto-confirmed (-y / YES=1):" "已自动确认（-y / YES=1）：") ${prompt}"
    return 0
  fi
  local reply=""
  if xyz_open_tty; then
    printf '%s [y/N] ' "${prompt}" >&"${XYZ_TTY_FD}"
    # shellcheck disable=SC2162
    read -r reply <&"${XYZ_TTY_FD}" || true
    xyz_close_tty
  else
    xyz_warn "$(xyz_t \
      "No TTY available for confirmation. Re-run with -y or YES=1 if you accept." \
      "没有可用的终端来确认。若你已了解并同意，请加 -y 或 YES=1 重试。")"
    return 1
  fi
  case "${reply}" in
    y|Y|yes|YES|Yes) return 0 ;;
    *) return 1 ;;
  esac
}

# --- download helpers -------------------------------------------------------
# Create the temp dir in the main shell. xyz_tmpdir is usually called inside
# $(...), a subshell, so creating it (and its EXIT trap) there would delete the
# directory as soon as the subshell returned.
xyz_init_tmpdir() {
  if [[ -z "${XYZ_TMPDIR:-}" || ! -d "${XYZ_TMPDIR}" ]]; then
    XYZ_TMPDIR="$(mktemp -d "${TMPDIR:-/tmp}/xyzsh.XXXXXX")"
    # shellcheck disable=SC2064
    trap "rm -rf '${XYZ_TMPDIR}'" EXIT
  fi
}

xyz_tmpdir() {
  if [[ -z "${XYZ_TMPDIR:-}" || ! -d "${XYZ_TMPDIR}" ]]; then
    xyz_error "internal: temp dir not initialised"
    exit 1
  fi
  printf '%s' "${XYZ_TMPDIR}"
}

xyz_fetch() {
  # xyz_fetch URL DEST
  local url="$1"
  local dest="$2"
  xyz_info "$(xyz_t "Downloading" "正在下载"): ${url}"
  xyz_info "$(xyz_t "Saving to" "保存到"): ${dest}"
  if xyz_need_cmd curl; then
    curl -fsSL --connect-timeout 20 --max-time 180 --retry 2 --retry-delay 1 \
      -o "${dest}" "${url}"
  elif xyz_need_cmd wget; then
    wget -q --timeout=60 -O "${dest}" "${url}"
  else
    xyz_error "$(xyz_t "Need curl or wget to download files." "需要 curl 或 wget 才能下载文件。")"
    exit 1
  fi
  if [[ ! -s "${dest}" ]]; then
    xyz_error "$(xyz_t "Download failed or file is empty:" "下载失败或文件为空：") ${url}"
    exit 1
  fi
  if xyz_need_cmd sha256sum; then
    xyz_info "SHA256: $(sha256sum "${dest}" | awk '{print $1}')"
  elif xyz_need_cmd shasum; then
    xyz_info "SHA256: $(shasum -a 256 "${dest}" | awk '{print $1}')"
  fi
}

xyz_run_upstream() {
  # xyz_run_upstream URL [args...]
  # Downloads an official installer, shows the URL and a short preview, then
  # runs it only after confirmation (unless -y / YES=1).
  local url="$1"
  shift
  local dest
  xyz_init_tmpdir
  dest="$(xyz_tmpdir)/upstream.sh"
  xyz_fetch "${url}" "${dest}"
  chmod +x "${dest}"
  xyz_info "$(xyz_t "Preview (first 20 lines):" "预览（前 20 行）：")"
  sed -n '1,20p' "${dest}" || true
  printf '%s\n' "${XYZ_C_DIM}...${XYZ_C_RESET}"
  # Default --dry-run: verify the download and preview, do not execute.
  # Scripts that forward --dry-run to upstream (e.g. docker) set
  # XYZ_FORWARD_DRY_RUN=1 so the official script still runs with that flag.
  if [[ "${XYZ_DRY_RUN:-0}" == "1" && "${XYZ_FORWARD_DRY_RUN:-0}" != "1" ]]; then
    xyz_info "$(xyz_t \
      "Dry-run: official script downloaded and previewed; not executing it." \
      "演练模式：已下载并预览官方脚本，不会执行。")"
    return 0
  fi
  if ! xyz_confirm "$(xyz_t \
    "Run this official upstream script?" \
    "运行这份官方上游脚本？")"; then
    xyz_error "$(xyz_t "Aborted by user." "已取消。")"
    exit 1
  fi
  xyz_step "$(xyz_t "Executing upstream script" "正在执行上游脚本")"
  # Never let the upstream script inherit our stdin: under `curl | bash` that
  # is the rest of this very script. Give it the terminal if there is one,
  # otherwise /dev/null. Interactive installers set XYZ_UPSTREAM_NEEDS_TTY=1.
  if xyz_open_tty; then
    local tty_fd="${XYZ_TTY_FD}"
    XYZ_TTY_FD=""
    bash "${dest}" "$@" <&"${tty_fd}"
    local rc=$?
    exec {tty_fd}>&- 2>/dev/null || true
    return "${rc}"
  fi
  if [[ "${XYZ_UPSTREAM_NEEDS_TTY:-0}" == "1" ]]; then
    xyz_error "$(xyz_t \
      "This official installer is interactive and needs a terminal. Log in with SSH and run: bash <(curl -fsSL ${XYZ_BASE}/${XYZ_NAME})" \
      "这个官方安装脚本需要交互，必须在终端里运行。请用 SSH 登录后执行：bash <(curl -fsSL ${XYZ_BASE}/${XYZ_NAME})")"
    exit 1
  fi
  bash "${dest}" "$@" </dev/null
}

# --- small shared helpers ----------------------------------------------------
xyz_strip_ansi() {
  sed -e 's/\x1b\[[0-9;?]*[A-Za-z]//g' -e 's/\r//g'
}

# Effective SSH port: sshd -T (what sshd really uses) > config files > env > 22.
xyz_effective_ssh_port() {
  local port=""
  if xyz_need_cmd sshd; then
    port="$(sshd -T 2>/dev/null | awk '$1=="port" {print $2; exit}' || true)"
  fi
  if [[ -z "${port}" && -d /etc/ssh/sshd_config.d ]]; then
    port="$(cat /etc/ssh/sshd_config.d/*.conf 2>/dev/null | awk 'tolower($1)=="port" {print $2; exit}' || true)"
  fi
  if [[ -z "${port}" && -f /etc/ssh/sshd_config ]]; then
    port="$(awk 'tolower($1)=="port" {print $2; exit}' /etc/ssh/sshd_config || true)"
  fi
  if [[ -z "${port}" && -n "${SSH_CONNECTION:-}" ]]; then
    port="$(printf '%s' "${SSH_CONNECTION}" | awk '{print $4}')"
  fi
  printf '%s' "${port:-22}"
}

xyz_has_systemd() {
  [[ -d /run/systemd/system ]] && xyz_need_cmd systemctl
}

# Back up a file once per run as FILE.xyz-bak-YYYYmmddHHMMSS and print the path.
xyz_backup_file() {
  local f="$1"
  local bak
  bak="${f}.xyz-bak-$(date +%Y%m%d%H%M%S)"
  if [[ -e "${f}" ]]; then
    cp -a "${f}" "${bak}"
    printf '%s' "${bak}"
  fi
}

# --- misc -------------------------------------------------------------------
xyz_usage_exit() {
  if [[ "${1:-}" != "" ]]; then
    printf '%s\n' "$1"
  fi
  exit 0
}

XYZ_NAME="caddy"

# xyz.sh/caddy — install Caddy and set up a reverse proxy with automatic HTTPS.
#
# Official project : https://caddyserver.com  (https://github.com/caddyserver/caddy)
# Binary           : official GitHub release tarball (default v2.11.9),
#                    SHA-512 pinned for amd64 / arm64 / armv7
#
# What it does:
#   - installs /usr/bin/caddy from the official release (no repository added)
#   - creates the `caddy` system user, /etc/caddy/Caddyfile, /var/lib/caddy
#   - installs the official systemd unit (from caddyserver/dist) and enables it
#   - with --domain / --to, adds a site block:   example.com { reverse_proxy 127.0.0.1:8080 }
#     Caddy then gets and renews a Let's Encrypt / ZeroSSL certificate itself.
#   - validates the Caddyfile with `caddy validate` before reloading
#
# Before using --domain: point the domain's A/AAAA record to this server and
# open TCP 80 and 443 (firewall and cloud security group).
#
# Usage:
#   curl -fsSL xyz.sh/caddy | bash -s -- -y
#   curl -fsSL xyz.sh/caddy | bash -s -- --domain example.com --to 127.0.0.1:8080 -y
#   curl -fsSL xyz.sh/caddy | bash -s -- --domain example.com --to 127.0.0.1:8080 --email me@example.com -y
#   curl -fsSL xyz.sh/caddy | bash -s -- --status
#   curl -fsSL xyz.sh/caddy | bash -s -- --uninstall -y
#   curl -fsSL xyz.sh/caddy | bash -s -- --dry-run
#
# Supported: Debian, Ubuntu, CentOS, Rocky, AlmaLinux (x86_64, aarch64,
# armv7). Root required. No telemetry is added by this wrapper.

set -euo pipefail

if [[ -z "${XYZ_COMMON_LOADED:-}" ]]; then
  _xyz_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
  if [[ -f "${_xyz_dir}/lib/common.sh" ]]; then
    # shellcheck source=lib/common.sh
    source "${_xyz_dir}/lib/common.sh"
  else
    echo "xyz.sh: missing lib/common.sh" >&2
    exit 1
  fi
fi

XYZ_NAME="caddy"
XYZ_TITLE="$(xyz_t "Caddy reverse proxy with automatic HTTPS" "Caddy 反向代理 + 自动 HTTPS")"
XYZ_UPSTREAM="https://github.com/caddyserver/caddy/releases"
CADDY_VERSION="${CADDY_VERSION:-2.11.9}"
CADDYFILE="/etc/caddy/Caddyfile"
UNIT="/etc/systemd/system/caddy.service"
xyz_init "$@"

DOMAIN=""; UPSTREAM=""; EMAIL=""; DO_STATUS=0; DO_UNINSTALL=0; INSTALL_ONLY=0
i=0
while [[ $i -lt ${#XYZ_ARGS[@]} ]]; do
  arg="${XYZ_ARGS[$i]}"
  case "${arg}" in
    --domain) i=$((i + 1)); DOMAIN="${XYZ_ARGS[$i]:-}" ;;
    --to|--upstream) i=$((i + 1)); UPSTREAM="${XYZ_ARGS[$i]:-}" ;;
    --email) i=$((i + 1)); EMAIL="${XYZ_ARGS[$i]:-}" ;;
    --install-only) INSTALL_ONLY=1 ;;
    --status) DO_STATUS=1 ;;
    --uninstall|--remove) DO_UNINSTALL=1 ;;
    --help|-h) XYZ_HELP=1 ;;
    *)
      xyz_error "$(xyz_t "Unknown argument:" "未知参数：") ${arg}"
      exit 1
      ;;
  esac
  i=$((i + 1))
done

if [[ "${XYZ_HELP:-}" == "1" ]]; then
  cat <<HINT
$(xyz_t "Usage:" "用法：")
  curl -fsSL xyz.sh/caddy | bash -s -- -y
  curl -fsSL xyz.sh/caddy | bash -s -- --domain example.com --to 127.0.0.1:8080 -y
  curl -fsSL xyz.sh/caddy | bash -s -- --domain example.com --to 127.0.0.1:8080 --email me@example.com -y
  curl -fsSL xyz.sh/caddy | bash -s -- --status
  curl -fsSL xyz.sh/caddy | bash -s -- --uninstall -y

$(xyz_t "Point DNS to this server and open TCP 80/443 before using --domain." "使用 --domain 前，请先把域名解析到本机并放行 TCP 80/443。")
HINT
  exit 0
fi

if [[ -n "${DOMAIN}" || -n "${UPSTREAM}" ]]; then
  [[ -n "${DOMAIN}" && -n "${UPSTREAM}" ]] || { xyz_error "$(xyz_t "--domain and --to go together." "--domain 和 --to 需要同时提供。")"; exit 1; }
  [[ "${DOMAIN}" =~ ^[A-Za-z0-9*]([A-Za-z0-9.-]*[A-Za-z0-9])?$ ]] || { xyz_error "--domain: invalid host name"; exit 1; }
  UP_RE='^(https?://)?[][A-Za-z0-9.:-]+(/[^[:space:]]*)?$'
  [[ "${UPSTREAM}" =~ ${UP_RE} ]] || { xyz_error "--to: like 127.0.0.1:8080"; exit 1; }
fi
[[ -z "${EMAIL}" || "${EMAIL}" =~ ^[^@[:space:]]+@[^@[:space:]]+\.[^@[:space:]]+$ ]] || { xyz_error "--email: invalid"; exit 1; }

if [[ "${DO_STATUS}" == "1" ]]; then
  if xyz_need_cmd caddy; then caddy version; else xyz_info "$(xyz_t "Caddy is not installed." "未安装 Caddy。")"; fi
  xyz_has_systemd && systemctl is-active caddy 2>/dev/null | sed 's/^/  caddy.service: /' || true
  [[ -f "${CADDYFILE}" ]] && { xyz_info "${CADDYFILE}:"; sed 's/^/  /' "${CADDYFILE}"; }
  exit 0
fi

xyz_require_root
xyz_require_supported_os

if [[ "${DO_UNINSTALL}" == "1" ]]; then
  xyz_info "$(xyz_t "Will stop caddy and remove /usr/bin/caddy and ${UNIT}. /etc/caddy and /var/lib/caddy (certificates) are kept." "将停止 caddy 并删除 /usr/bin/caddy 与 ${UNIT}。保留 /etc/caddy 和 /var/lib/caddy（证书）。")"
  if [[ "${XYZ_DRY_RUN:-0}" == "1" ]]; then xyz_info "$(xyz_t "Dry-run: nothing removed." "演练模式：未删除。")"; exit 0; fi
  xyz_confirm "$(xyz_t "Uninstall Caddy?" "卸载 Caddy？")" || exit 1
  if xyz_has_systemd; then systemctl disable --now caddy 2>/dev/null || true; fi
  rm -f /usr/bin/caddy "${UNIT}"
  xyz_has_systemd && systemctl daemon-reload || true
  xyz_info "$(xyz_t "Removed." "已删除。")"
  exit 0
fi

caddy_arch() {
  case "$(uname -m)" in
    x86_64|amd64) printf 'amd64' ;;
    aarch64|arm64) printf 'arm64' ;;
    armv7l|armv7*) printf 'armv7' ;;
    *) xyz_error "$(xyz_t "Unsupported architecture:" "不支持的架构：") $(uname -m)"; exit 1 ;;
  esac
}
caddy_sha512() {
  [[ "${CADDY_VERSION}" == "2.11.9" ]] || return 1
  case "$1" in
    amd64) printf '0e85544340290a16ce4bfb76fe7d65e9de1bf3a6e67f5ccfff30b30d27ea4c73e078077b7bf3e58ae60b6b12e44327705287059c775bca5782e8ee85ea7edd75' ;;
    arm64) printf '9e5e76d7888542924de2c25353ae87c5f77e2a22c5b1198633cae13688922282e05383d142599205c88d8d80eee5e967d291214d7abce4835329a191b20dd6e0' ;;
    armv7) printf 'ea042518bfb5eec5070a3119430263ae920b2d1e878c733a80d3d0ced1168afe5816362f295de46915d651a67f31f4d8a67ac67326f507d90cda71274b8ee689' ;;
    *) return 1 ;;
  esac
}

ARCH="$(caddy_arch)"
TARBALL="caddy_${CADDY_VERSION}_linux_${ARCH}.tar.gz"
URL="https://github.com/caddyserver/caddy/releases/download/v${CADDY_VERSION}/${TARBALL}"
NEED_BIN=1
if xyz_need_cmd caddy && caddy version 2>/dev/null | grep -q "^v${CADDY_VERSION}"; then
  NEED_BIN=0
fi

xyz_step "$(xyz_t "Planned changes" "计划变更")"
if [[ "${NEED_BIN}" == "1" ]]; then
  printf '  %s: %s -> /usr/bin/caddy\n' "$(xyz_t "Install" "安装")" "${URL}"
else
  printf '  %s: %s\n' "$(xyz_t "Already installed" "已安装")" "$(caddy version | head -1)"
fi
printf '  %s: caddy, %s, /var/lib/caddy, %s\n' "$(xyz_t "System user / files" "系统用户 / 文件")" "${CADDYFILE}" "${UNIT}"
if [[ -n "${DOMAIN}" ]]; then
  printf '  %s: %s { reverse_proxy %s }\n' "$(xyz_t "Site" "站点")" "${DOMAIN}" "${UPSTREAM}"
  resolved="$(getent ahostsv4 "${DOMAIN}" 2>/dev/null | awk '{print $1; exit}' || true)"
  local_ip="$(ip -4 route get 1.1.1.1 2>/dev/null | awk '{for(i=1;i<=NF;i++) if($i=="src"){print $(i+1); exit}}' || true)"
  printf '  DNS %s -> %s (%s %s)\n' "${DOMAIN}" "${resolved:-?}" "$(xyz_t "this server's route source:" "本机出口地址：")" "${local_ip:-?}"
  if [[ -z "${resolved}" ]]; then
    xyz_warn "$(xyz_t "${DOMAIN} does not resolve yet; HTTPS certificates will fail until it does." "${DOMAIN} 目前无法解析；在解析生效前证书申请会失败。")"
  fi
fi
if xyz_need_cmd ss; then
  busy="$(ss -ltnp 2>/dev/null | awk '$4 ~ /[:.](80|443)$/' | grep -v caddy || true)"
  [[ -n "${busy}" ]] && xyz_warn "$(xyz_t "Ports 80/443 are used by another program:" "80/443 端口已被其它程序占用：") $(printf '%s' "${busy}" | awk '{print $4, $6}' | tr '\n' ' ')"
fi

if [[ "${XYZ_DRY_RUN:-0}" == "1" ]]; then
  xyz_info "$(xyz_t "Dry-run: nothing installed or written." "演练模式：未安装、未写入任何内容。")"
  exit 0
fi
xyz_confirm "$(xyz_t "Install / configure Caddy?" "安装 / 配置 Caddy？")" || { xyz_error "$(xyz_t "Aborted by user." "已取消。")"; exit 1; }

if [[ "${NEED_BIN}" == "1" ]]; then
  xyz_need_cmd tar || xyz_ensure_cmds tar
  xyz_init_tmpdir
  T="$(xyz_tmpdir)"
  xyz_fetch "${URL}" "${T}/${TARBALL}"
  want="$(caddy_sha512 "${ARCH}" || true)"
  if [[ -z "${want}" ]]; then
    xyz_fetch "https://github.com/caddyserver/caddy/releases/download/v${CADDY_VERSION}/caddy_${CADDY_VERSION}_checksums.txt" "${T}/sums.txt"
    want="$(awk -v f="${TARBALL}" '$2==f {print $1}' "${T}/sums.txt")"
  fi
  got="$(sha512sum "${T}/${TARBALL}" | awk '{print $1}')"
  if [[ -z "${want}" || "${want}" != "${got}" ]]; then
    xyz_error "$(xyz_t "SHA-512 mismatch for" "SHA-512 不匹配：") ${TARBALL}"
    exit 1
  fi
  xyz_info "$(xyz_t "SHA-512 verified." "SHA-512 已校验。")"
  tar -xzf "${T}/${TARBALL}" -C "${T}" caddy
  install -m 0755 "${T}/caddy" /usr/bin/caddy
  xyz_info "$(xyz_t "Installed" "已安装") $(/usr/bin/caddy version | head -1)"
fi

if ! getent group caddy >/dev/null; then groupadd --system caddy; fi
if ! id caddy >/dev/null 2>&1; then
  useradd --system --gid caddy --create-home --home-dir /var/lib/caddy --shell /usr/sbin/nologin --comment "Caddy web server" caddy 2>/dev/null \
    || useradd --system -g caddy -m -d /var/lib/caddy -s /sbin/nologin caddy
fi
mkdir -p /etc/caddy /var/lib/caddy
chown -R caddy:caddy /var/lib/caddy

if [[ ! -f "${CADDYFILE}" ]]; then
  {
    printf '# Caddyfile written by xyz.sh/caddy %s. Docs: https://caddyserver.com/docs/caddyfile\n' "${XYZ_VERSION}"
    if [[ -n "${EMAIL}" ]]; then printf '{\n\temail %s\n}\n\n' "${EMAIL}"; fi
    if [[ -z "${DOMAIN}" ]]; then
      printf ':80 {\n\trespond "Caddy is running (installed by xyz.sh/caddy)."\n}\n'
    fi
  } > "${CADDYFILE}"
fi
BAK=""
if [[ -n "${DOMAIN}" ]]; then
  BAK="$(xyz_backup_file "${CADDYFILE}")"
  # Replace an earlier xyz.sh block for the same domain.
  sed -i "/^# BEGIN xyz.sh site ${DOMAIN//./\\.}\$/,/^# END xyz.sh site ${DOMAIN//./\\.}\$/d" "${CADDYFILE}"
  # The placeholder :80 site would conflict with HTTP->HTTPS redirects; drop it.
  sed -i '/^:80 {$/,/^}$/d' "${CADDYFILE}"
  cat >> "${CADDYFILE}" <<SITE

# BEGIN xyz.sh site ${DOMAIN}
${DOMAIN} {
	reverse_proxy ${UPSTREAM}
	encode zstd gzip
}
# END xyz.sh site ${DOMAIN}
SITE
fi

if ! /usr/bin/caddy validate --config "${CADDYFILE}" --adapter caddyfile >/dev/null 2>&1; then
  xyz_error "$(xyz_t "caddy validate rejected the Caddyfile:" "caddy validate 校验 Caddyfile 失败：")"
  /usr/bin/caddy validate --config "${CADDYFILE}" --adapter caddyfile 2>&1 | tail -5 || true
  [[ -n "${BAK}" ]] && cp -a "${BAK}" "${CADDYFILE}" && xyz_info "$(xyz_t "Restored" "已恢复") ${BAK}"
  exit 1
fi
xyz_info "$(xyz_t "caddy validate: Caddyfile is valid." "caddy validate：Caddyfile 有效。")"
/usr/bin/caddy fmt --overwrite "${CADDYFILE}" >/dev/null 2>&1 || true
chown -R root:caddy /etc/caddy

mkdir -p "$(dirname "${UNIT}")"
cat > "${UNIT}" <<'UNITFILE'
# Official unit from https://github.com/caddyserver/dist (caddy.service), installed by xyz.sh/caddy
[Unit]
Description=Caddy
Documentation=https://caddyserver.com/docs/
After=network.target network-online.target
Requires=network-online.target

[Service]
Type=notify
User=caddy
Group=caddy
ExecStart=/usr/bin/caddy run --environ --config /etc/caddy/Caddyfile
ExecReload=/usr/bin/caddy reload --config /etc/caddy/Caddyfile --force
TimeoutStopSec=5s
LimitNOFILE=1048576
PrivateTmp=true
ProtectSystem=full
AmbientCapabilities=CAP_NET_ADMIN CAP_NET_BIND_SERVICE

[Install]
WantedBy=multi-user.target
UNITFILE

if [[ "${INSTALL_ONLY}" == "1" ]]; then
  xyz_info "$(xyz_t "--install-only: not starting the service." "--install-only：不启动服务。")"
  exit 0
fi

if xyz_has_systemd; then
  systemctl daemon-reload
  if systemctl is-active --quiet caddy; then
    systemctl reload caddy
  else
    systemctl enable --now caddy
  fi
  systemctl --no-pager --lines=0 status caddy || true
  [[ -n "${DOMAIN}" ]] && xyz_info "$(xyz_t "Caddy will request a certificate for ${DOMAIN}. Check: journalctl -u caddy -f, then open https://${DOMAIN}" "Caddy 会为 ${DOMAIN} 申请证书。查看日志：journalctl -u caddy -f，然后访问 https://${DOMAIN}")"
  xyz_info "$(xyz_t "Caddy is running." "Caddy 已运行。")"
else
  xyz_warn "$(xyz_t "No systemd here (container?). Installed and validated; start manually: caddy start --config ${CADDYFILE}" "当前没有 systemd（可能是容器）。已安装并校验配置，请手动启动：caddy start --config ${CADDYFILE}")"
fi