# 添加OpenResty仓库
yum install -y yum-utils
yum-config-manager --add-repo https://openresty.org/package/centos/openresty.repo

# 安装OpenResty
yum install -y openresty

# 安装Resty命令行工具
yum install -y openresty-resty

# 启动服务
systemctl start openresty
systemctl enable openresty

# 查看版本
openresty -v

# 输出示例
nginx version: openresty/1.25.3.1

三、Lua基础语法

3.1 Lua基本语法

-- 变量定义
local name = "OpenResty"
local count = 100

-- 表（Table）
local user = {
    id = 1,
    name = "风哥1号",
    age = 30
}

-- 函数
local function add(a, b)
    return a + b
end

-- 条件判断
if score >= 90 then
    print("优秀")
elseif score >= 60 then
    print("及格")
end

-- 循环
for i = 1, 10 do
    print(i)
end

3.2 OpenResty常用API

-- 获取请求参数
local args = ngx.req.get_uri_args()
local name = args["name"]

-- 输出响应
ngx.say("Hello, OpenResty!")
ngx.exit(200)

-- 日志输出
ngx.log(ngx.ERR, "错误日志")
ngx.log(ngx.INFO, "信息日志")

-- JSON编解码
local json = require("cjson")
local encoded = json.encode({name = "风哥1号"})
local decoded = json.decode('{"name":"风哥1号"}')

四、Nginx配置与Lua集成

4.1 基本配置

# nginx.conf
http {
    lua_package_path "/usr/local/openresty/lualib/?.lua;;";
    lua_shared_dict cache 128m;
    
    server {
        listen 80;
        
        location / {
            content_by_lua_block {
                ngx.say("<h1>Hello OpenResty!</h1>")
            }
        }
        
        location /api {
            content_by_lua_file lua/api.lua;
        }
    }
}

五、API网关实现

5.1 路由配置

-- lua/router.lua
local routes = {
    ["/api/users"] = {handler = "api.users"},
    ["/api/orders"] = {handler = "api.orders"}
}

function route()
    local uri = ngx.var.uri
    local route = routes[uri]
    if route then
        local handler = require(route.handler)
        handler.process()
    end
end

5.2 认证中间件

-- lua/auth.lua
local jwt = require("resty.jwt")

function verify_token()
    local auth_header = ngx.req.get_headers()["Authorization"]
    if not auth_header then
        ngx.status = 401
        ngx.say('{"error": "Unauthorized"}')
        return ngx.exit(401)
    end
    
    local token = auth_header:match("Bearer%s+(.+)")
    local jwt_obj = jwt:verify("secret", token)
    
    if not jwt_obj.verified then
        ngx.status = 401
        return ngx.exit(401)
    end
    
    ngx.ctx.user = jwt_obj.payload
end

六、Redis集成

6.1 Redis操作

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

red:connect("127.0.0.1", 6379)

-- 设置值
red:set("key", "value")
red:setex("key", 3600, "value")

-- 获取值
local value = red:get("key")

-- 删除
red:del("key")

-- 设置过期时间
red:expire("key", 3600)

-- 连接池
red:set_keepalive(10000, 100)

七、MySQL集成

7.1 MySQL操作

local mysql = require("resty.mysql")
local db, err = mysql:new()

db:connect({
    host = "127.0.0.1",
    port = 3306,
    database = "test",
    user = "root",
    password = "password"
})

-- 查询
local res = db:query("SELECT * FROM users WHERE id = 1")

-- 插入
db:query("INSERT INTO users(name, email) VALUES('风哥1号', 'test@fgedu.net.cn')")

-- 更新
db:query("UPDATE users SET name='风哥2号' WHERE id=1")

-- 连接池
db:set_keepalive(10000, 100)

八、限流与缓存

8.1 限流配置

local limit_req = require("resty.limit.req")

local lim = limit_req.new("limit", 100, 200)
local key = ngx.var.binary_remote_addr
local delay, err = lim:incoming(key, true)

if not delay then
    if err == "rejected" then
        ngx.status = 429
        ngx.say('{"error": "Too Many Requests"}')
        return ngx.exit(429)
    end
end

8.2 缓存实现

local cache = ngx.shared.cache

-- 设置缓存
cache:set("key", "value", 3600)

-- 获取缓存
local value = cache:get("key")

-- 删除缓存
cache:delete("key")

-- 缓存穿透保护
local value = cache:get("key")
if not value then
    value = query_from_db()
    cache:set("key", value, 3600)
end

九、性能优化

9.1 连接池配置

# nginx.conf
http {
    lua_socket_pool_size 100;
    lua_socket_connect_timeout 3s;
    lua_socket_send_timeout 3s;
    lua_socket_read_timeout 3s;
    lua_socket_buffer_size 4k;
}

9.2 性能调优

# nginx.conf
worker_processes auto;
worker_cpu_affinity auto;

events {
    worker_connections 65535;
    multi_accept on;
}

http {
    lua_max_pending_timers 1024;
    lua_max_running_timers 256;
    
    lua_shared_dict cache 256m;
    lua_shared_dict limit 10m;
}

十、运维命令

10.1 常用管理命令

# 测试配置
openresty -t

# 重载配置
openresty -s reload

# 使用resty命令执行Lua
resty -e 'print("Hello")'

# 查看进程
ps -ef | grep nginx

# 查看连接
ss -tlnp | grep 80

十一、最佳实践

配置项	建议值	说明
worker_processes	auto	自动匹配CPU核心
lua_shared_dict	128m+	共享内存大小
连接池大小	100	数据库连接池