OpenResty+nginx+lua+redis实现二级缓存

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Kubernetes40 Java22 中间件15 其他14 Docker12 Linux11 MySQL9 Nginx8 Redis3

382 字

2 分钟

OpenResty+nginx+lua+redis实现二级缓存

2021-06-24

Nginx

OpenResty

下载OpenResty镜像
Terminal window
```
1
docker pull openresty/openresty
```

运行镜像

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docker run -d -p 880:80 --name openresty --restart always -v /etc/localtime:/etc/localtime openresty/openresty

进入容器
Terminal window
```
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docker exec -it openresty /bin/bash
```

安装lua

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apt-get update -y
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apt-get install -y gcc
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apt-get install -y curl
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apt-get install -y make
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apt-get install -y vim
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apt-get install libreadline-dev -y
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curl -R -O http://www.lua.org/ftp/lua-5.3.5.tar.gz
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tar -zxf lua-5.3.5.tar.gz
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cd lua-5.3.5
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make linux test
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make install

编写lua脚本并上传到服务器

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ngx.header.content_type = "application/json;charset=utf8"
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--获取本地缓存
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local cache_ngx = ngx.shared.dis_cache;
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-- 获取本地缓存数据
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local ngCache = cache_ngx:get('lua:application-data')
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if ngCache == "" or ngCache == nil then
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    --引入redis库
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    local cjson = require("cjson")
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    local redis = require("resty.redis")
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    local red = redis:new()
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    red:set_timeout(2000)
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    local ip = "127.0.0.1"
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    local port = 6379
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    red:connect(ip, port)
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    red:auth("123456")
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    local redCache = red:get("lua:application-data")
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    if redCache == ngx.null or redCache == "" or redCache == nil then
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        --引入mysql库
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        local mysql = require("resty.mysql")
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        local db = mysql:new()
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        db:set_timeout(3000)
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        local props = {
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            host = "127.0.0.1",
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            port = 3306,
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            database = "test",
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            user = "root",
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            password = "root"
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        }
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        local res = db:connect(props)
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        local select_sql = "SELECT xxx from tb_level where xxx"
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        res = db:query(select_sql)
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        db:close()
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        red:set("lua:application-data", cjson.encode(res))
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        red:close()
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        --将redis中获取到的数据存入nginx本地缓存10分钟 测试阶段先1分钟
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        cache_ngx:set('lua-game-milk-tea:level-data', cjson.encode(res), 1 * 60)
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        ngx.say("{\"code\":0,\"message\":\"sql success\",\"data\":" .. cjson.encode(res) .. "}")
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    else
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        --将redis中获取到的数据存入nginx本地缓存10分钟 测试阶段先1分钟
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        cache_ngx:set('lua:application-data', redCache, 1 * 60)
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        ngx.say("{\"code\":0,\"message\":\"redis success\",\"data\":" .. redCache .. "}")
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    end
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else
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    ngx.say("{\"code\":0,\"message\":\"nginx success\",\"data\":" .. ngCache .. "}")
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end

特别说明

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lua读取redis数据返回结果为空时，返回的结果不是nil而是userdata类型的ngx.null

在http节点下开启nginx共享内存

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vim /usr/local/openresty/nginx/conf/nginx.conf

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lua_shared_dict dis_cache 10m;

在server节点添加lua配置

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location /lua {
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    content_by_lua_file /opt/lua/cache.lua;
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    add_header Access-Control-Allow-Origin *;
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    add_header Access-Control-Allow-Methods 'GET, POST, OPTIONS';
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    add_header Access-Control-Allow-Headers '*';
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}