#!/bin/bash
set -euo pipefail

# 初始化变量
ACTION=""
VIP=""
PRIORITY=150
INTERFACE=""
KEEPALIVED_CONF="/etc/keepalived/keepalived.conf"
CHECK_SCRIPT="/usr/local/bin/check_haproxy.sh"

# 打印帮助信息
usage() {
    echo "用法: $0 [操作] [选项]"
    echo "操作:"
    echo "  --install   安装并配置keepalived"
    echo "  --uninstall 卸载keepalived并清理配置"
    echo "安装选项:"
    echo "  --vip <VIP>          必选，虚拟IP（格式:192.168.1.100/24）"
    echo "  --priority <数值>    可选，优先级（默认150，主节点设高）"
    echo "示例:"
    echo "  安装主节点: $0 --install --vip 192.168.1.100/24 --priority 150"
    echo "  安装备节点: $0 --install --vip 192.168.1.100/24 --priority 140"
    echo "  卸载: $0 --uninstall"
    exit 1
}

# 解析参数
while [[ $# -gt 0 ]]; do
    case "$1" in
        --install|--uninstall)
            ACTION="$1"
            shift
            ;;
        --vip)
            VIP="$2"
            shift 2
            ;;
        --priority)
            PRIORITY="$2"
            shift 2
            ;;
        *)
            echo "错误：未知参数 $1"
            usage
            ;;
    esac
done

# 校验操作参数
if [[ -z "$ACTION" ]]; then
    echo "错误：必须指定 --install 或 --uninstall"
    usage
fi

# 检查root权限
if [[ $EUID -ne 0 ]]; then
    echo "错误：脚本必须以root权限运行（使用sudo）"
    exit 1
fi

# 获取默认网卡
get_default_interface() {
    INTERFACE=$(ip -br link show | grep -v LOOPBACK | awk '{print $1}' | head -n 1)
    if [[ -z "$INTERFACE" ]]; then
        echo "错误：无法获取默认网卡，请手动检查网络接口"
        exit 1
    fi
    echo "使用默认网卡：$INTERFACE"
}

# 安装keepalived
install_keepalived() {
    # 校验安装参数
    if [[ -z "$VIP" ]]; then
        echo "错误：安装必须指定 --vip（格式:IP/子网掩码）"
        usage
    fi
    if ! [[ "$VIP" =~ ^[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/[0-9]+$ ]]; then
        echo "错误：VIP格式无效（正确格式：192.168.1.100/24）"
        exit 1
    fi

    # 获取网卡
    get_default_interface

    # 安装软件
    echo "===== 开始安装keepalived ====="
    apt update >/dev/null
    apt install -y keepalived >/dev/null || { echo "keepalived安装失败"; exit 1; }

    # 备份原有配置（若存在）
    if [[ -f "$KEEPALIVED_CONF" ]]; then
        mv "$KEEPALIVED_CONF" "${KEEPALIVED_CONF}.bak.$(date +%F_%H%M%S)"
        echo "已备份原有配置文件"
    fi

    # 创建健康检查脚本
    echo "创建健康检查脚本..."
    cat > "$CHECK_SCRIPT" << 'EOF'
#!/bin/bash
if ! pgrep -x "haproxy" >/dev/null; then
    systemctl stop keepalived
    exit 1
else
    exit 0
fi
EOF
    chmod +x "$CHECK_SCRIPT"

    # 生成配置文件
    echo "生成keepalived配置..."
    cat > "$KEEPALIVED_CONF" << EOF
global_defs {
    router_id LVS_K8S_$(hostname)
}

vrrp_script check_haproxy {
    script "$CHECK_SCRIPT"
    interval 2
    weight -20
}

vrrp_instance VI_1 {
    state $(if [[ $PRIORITY -ge 150 ]]; then echo "MASTER"; else echo "BACKUP"; fi)
    interface $INTERFACE
    virtual_router_id 51
    priority $PRIORITY
    advert_int 1
    authentication {
        auth_type PASS
        auth_pass k8s_ha_auth_2024
    }
    virtual_ipaddress {
        $VIP
    }
    track_script {
        check_haproxy
    }
}
EOF

    # 启动服务
    systemctl enable  keepalived
    systemctl start keepalived
    if systemctl is-active --quiet keepalived; then
        echo "===== keepalived安装完成 ====="
        echo "VIP：$VIP"
        echo "优先级：$PRIORITY"
        echo "网卡：$INTERFACE"
    else
        echo "错误：keepalived启动失败，请查看日志 journalctl -u keepalived"
        exit 1
    fi
}

# 卸载keepalived
uninstall_keepalived() {
    echo "===== 开始卸载keepalived ====="

    # 停止服务
    if systemctl is-active --quiet keepalived; then
        systemctl stop keepalived
        echo "已停止keepalived服务"
    fi

    # 卸载软件
    if dpkg -l keepalived &>/dev/null; then
        apt purge -y keepalived >/dev/null
        apt autoremove -y >/dev/null
        echo "已卸载keepalived软件包"
    else
        echo "keepalived未安装，跳过卸载"
    fi

    # 清理配置文件（保留备份提示）
    if [[ -d /etc/keepalived/ ]]; then
        mv /etc/keepalived/ "/etc/keepalived.bak.$(date +%F_%H%M%S)"
        echo "配置文件已备份至 /etc/keepalived.bak.xxx"
    fi

    # 清理健康检查脚本
    if [[ -f "$CHECK_SCRIPT" ]]; then
        rm -f "$CHECK_SCRIPT"
        echo "已删除健康检查脚本"
    fi

    echo "===== keepalived卸载完成 ====="
}

# 执行操作
case "$ACTION" in
    --install)
        install_keepalived
        ;;
    --uninstall)
        uninstall_keepalived
        ;;
    *)
        usage
        ;;
esac