# Ubuntu/Debian
sudo apt-get install openresty
# CentOS
yum install openresty

sudo apt-get install redis-server  # Debian系
sudo yum install redis             # RedHat系

http {
    lua_package_path "/usr/local/openresty/lualib/?.lua;;";
    lua_shared_dict ip_limit 10m;  # 共享內存區(qū)

    server {
        listen 80;
        server_name _;

        location / {
            access_by_lua_file /usr/local/lua/ip_block.lua;  # 核心攔截腳本
            root /var/www/html;
        }
    }
}

local redis = require "resty.redis"
local red = redis:new()

-- Redis連接參數(shù)
local redis_host = "127.0.0.1"
local redis_port = 6379
local redis_timeout = 1000  -- 毫秒
local redis_auth = nil       -- 無密碼留空

-- 攔截參數(shù)
local block_time = 86400     -- 封禁時間（1天）
local time_window = 60       -- 統(tǒng)計窗口（1分鐘）
local max_requests = 60     -- 最大請求數(shù)

-- 獲取客戶端IP
local function get_client_ip()
    local headers = ngx.req.get_headers()
    return headers["X-Real-IP"] or headers["x_forwarded_for"] or ngx.var.remote_addr
end

-- 連接Redis
local function connect_redis()
    red:set_timeout(redis_timeout)
    local ok, err = red:connect(redis_host, redis_port)
    if not ok then
        ngx.log(ngx.ERR, "Redis連接失敗: ", err)
        return nil
    end
    if redis_auth then
        local ok, err = red:auth(redis_auth)
        if not ok then ngx.log(ngx.ERR, "Redis認證失敗: ", err) end
    end
    return ok
end

-- 主邏輯
local client_ip = get_client_ip()
local counter_key = "limit:count:" .. client_ip
local block_key = "limit:block:" .. client_ip

-- 檢查是否已封禁
local is_blocked, err = red:get(block_key)
if tonumber(is_blocked) == 1 then
    ngx.exit(ngx.HTTP_FORBIDDEN)  -- 直接返回403
end

-- 統(tǒng)計請求次數(shù)
connect_redis()
local current_count = red:incr(counter_key)
if current_count == 1 then
    red:expire(counter_key, time_window)  -- 首次設置過期時間
end

-- 觸發(fā)封禁條件
if current_count > max_requests then
    red:setex(block_key, block_time, 1)   -- 封禁并設置1天過期
    red:del(counter_key)                  -- 刪除計數(shù)器
    ngx.exit(ngx.HTTP_FORBIDDEN)
end

-- 釋放Redis連接
red:set_keepalive(10000, 100)

ngx.timer.at(0, function()
    local log_msg = string.format("%s - IP %s blocked at %s", 
        ngx.var.host, client_ip, ngx.localtime())
    local log_file = io.open("/var/log/nginx/blocked_ips.log", "a")
    log_file:write(log_msg, "\n")
    log_file:close()
end)

# 模擬高頻請求
ab -n 100 -c 10 http://your-domain.com/
# 檢查Redis
redis-cli keys "limit:block:*"

redis-cli ttl "limit:block:1.2.3.4"  # 返回剩余秒數(shù)

# 采集Redis指標
prometheus-redis-exporter --redis.address=localhost:6379

local rule_key = "limit:rule:" .. ngx.var.uri
local custom_rule = red:hget(rule_key, "max_requests")