Nginx中的Lua使用10

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Nging中的Lua使用

ngx_lua操作redis

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Nginx 支持三种方法访问Redis
- HttpRedis模块
	指令少, 功能单一, 适合简单缓存
- HttpRedis2Module
	比较灵活, 功能强大
- lua-resty-redis库
	OpenResty提供的操作Redis的接口库, 适合复杂业务逻辑

查询基本使用API

OpenResty官方文档

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https://github.com/openresty/lua-resty-redis

在lua-resty-redis中, 所有Redis命令都有自己的方法, 名称与Redis命令相同, 只是全部小写

修改RestyNginx配置文件

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# sudo vi /usr/local/openresty/nginx/conf/nginx.conf
		location /showRedis{
            default_type 'text/html';
            content_by_lua_block{
                -- 引入Redis接口模块
                local redis = require "resty.redis"
                -- 创建Redis对象
                local redisObj = redis:new()
                -- 设置超时时间
                redisObj:set_timeout(1000)
                local ok,err = redisObj:connect("192.168.253.135",6379)
                if not ok then
                    ngx.say('failed to connection with redis',err)
                    return
                else
                    ngx.say('connect to Redis success','<br>')
                end
                -- 向Redis存入数据
                local ok,err = redisObj:set('username','ni9ne')
                if ok then
                    ngx.say('set value username_ni9ne:', ok,'<br>')
                else
                    ngx.say('failed to set value',err)
                    return
                end
                -- 从Redis中获取数据
                local res,err = redisObj:get('username')
                ngx.say('<h1>',res,'<h1>')
                -- 关闭Redis连接
                redisObj:close()
            }
        }

验证配置路由结果

image-20220609012350518

image-20220609012412032

ngx_lua操作MySql

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在ngx_lua中, MySql有两种访问方式:
- 使用OpenResty自带的ngx_lua模块和lua-resty-mysql模块
- 安装drizzle_nginx_module(HttpDrizzleModule)模块
	文档路径为: https://github.com/openresty/drizzle-nginx-module

已安装OpenResty, 使用lua-resty-mysql

查询基本使用API

OpenResty官方文档

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https://github.com/openresty/lua-resty-mysql

单条数据查询

修改Nginx配置文件

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# sudo vi /usr/local/openresty/nginx/conf/nginx.conf
		location /mysqlQuery{
            default_type 'text/html';
            content_by_lua_block{
        		-- 引入resty.msyql模块
                local mysql = require 'resty.mysql'
            	-- 创建连接对象
                local db = mysql:new()
            	-- 建立连接
                local ok,err = db:connect{
                    host="192.168.253.134",
                    port=3306,
                    user="root",
                    password="xxxxxx",
                    database="nginx_db"
                }
        		-- 验证是否连接成功
                if not ok then
                    ngx.say('failed connected to mysql',err)
                    return
                else
                    ngx.say('mysql connected success'..'<br/>')
                end
            	-- 设置超时时间
                db:set_timeout(1000)
            	-- 发送SQL语句
                db:send_query('select * from users where id=2')
            	-- 接收返回结果
                local res,err,errcode,sqlstate = db:read_result()
            	-- 输出信息到页面
                if not err then
                    ngx.say('res[1].username:',res[1].username)
                    ngx.say('<br/>')
                end
                ngx.say('err:',err)
                ngx.say('<br/>')
                ngx.say('errcode:',errcode)
                ngx.say('<br/>')
                ngx.say('sqlstate:',sqlstate)
            	-- 关闭连接
                db:close()
            }
        }

验证配置路由结果

image-20220609020926699

SQL错误信息如下所示:

image-20220609021614599

多条数据查询

修改Nginx配置文件

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# sudo vi /usr/local/openresty/nginx/conf/nginx.conf
        location /mysqlQuery{
            default_type 'text/html';
            content_by_lua_block{
                local mysql = require 'resty.mysql'
                local db = mysql:new()
                local ok,err = db:connect{
                    host="192.168.253.134",
                    port=3306,
                    user="root",
                    password="xxxxxx",
                    database="nginx_db"
                }
                if not ok then
                    ngx.say('failed connected to mysql',err)
                    return
                else
                    ngx.say('mysql connected success'..'<br/>')
                end
                db:set_timeout(1000)
                db:send_query('select * from users')
                local res,err,errcode,sqlstate = db:read_result()
                if not err then
                    --[[
                    ngx.say('res[1].username:',res[1].username)
                    ngx.say('<br/>')
                    --]]
            		# for循环解析多条数据
                    for i,v in pairs(res) do
                        ngx.say('username:'..v.username,'|','salary:'..v.salary)
                        ngx.say('<br/>')
                    end
                end
                ngx.say('err:',err)
                ngx.say('<br/>')
                ngx.say('errcode:',errcode)
                ngx.say('<br/>')
                ngx.say('sqlstate:',sqlstate)
                db:close()
            }
        }

验证配置路由结果

image-20220609023333612

使用CJson编码数据table

修改Nginx配置文件

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# sudo vi /usr/local/openresty/nginx/conf/nginx.conf
        location /mysqlQuery{
            default_type 'text/html';
            content_by_lua_block{
                local mysql = require 'resty.mysql'
            	# 引入cjson模块, 也可以在http块中初始化
            	# init_by_lua_block{ cjson=require 'cjson' }
                local cjson = require 'cjson'
                local db = mysql:new()
                local ok,err = db:connect{
                    host="192.168.253.134",
                    port=3306,
                    user="root",
                    password="xxxxxx",
                    database="nginx_db"
                }
                if not ok then
                    ngx.say('failed connected to mysql',err)
                    return
                else
                    ngx.say('mysql connected success'..'<br/>')
                end
                db:set_timeout(1000)
                db:send_query('select * from users')
                local res,err,errcode,sqlstate = db:read_result()
                if not err then
                    --[[
                    for i,v in pairs(res) do
                        ngx.say('username:'..v.username,'|','salary:'..v.salary)
                        ngx.say('<br/>')
                    end
                    --]]
                    local res_json = cjson.encode(res)
                    ngx.say('res_json: ',res_json)
                    ngx.say('<br/>')
                end
                ngx.say('err:',err)
                ngx.say('<br/>')
                ngx.say('errcode:',errcode)
                ngx.say('<br/>')
                ngx.say('sqlstate:',sqlstate)
                db:close()
            }
        }

验证配置路由结果

image-20220609023722667

使用query()执行查询/读取

使用query()可以替代send_query()+read_result()

修改Nginx配置文件

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# sudo vi /usr/local/openresty/nginx/conf/nginx.conf
        location /mysqlQuery{
            default_type 'text/html';
            content_by_lua_block{
                local mysql = require 'resty.mysql'
                local cjson = require 'cjson'
                local db = mysql:new()
                local ok,err = db:connect{
                    host="192.168.253.134",
                    port=3306,
                    user="root",
                    password="xxxxxx",
                    database="nginx_db"
                }
                if not ok then
                    ngx.say('failed connected to mysql',err)
                    return
                else
                    ngx.say('mysql connected success'..'<br/>')
                end
                db:set_timeout(1000)
                local sql = 'select * from users'
            	# 使用query()
                local res,err,errcode,sqlstate = db:query(sql)
                if res then
                    local res_json = cjson.encode(res)
                    ngx.say('res_json: ',res_json)
                    ngx.say('<br/>')
                end
                ngx.say('err:',err)
                ngx.say('<br/>')
                ngx.say('errcode:',errcode)
                ngx.say('<br/>')
                ngx.say('sqlstate:',sqlstate)
                db:close()
            }
        }

增删改操作

增删改操作只需要将对于SQL放入query()中即可, 仅返回数据不同

修改Nginx配置文件

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# sudo vi /usr/local/openresty/nginx/conf/nginx.conf
        location /mysqlQuery{
            default_type 'text/html';
            content_by_lua_block{
                local mysql = require 'resty.mysql'
                local cjson = require 'cjson'
                local db = mysql:new()
                local ok,err = db:connect{
                    host="192.168.253.134",
                    port=3306,
                    user="root",
                    password="xxxxxx",
                    database="nginx_db"
                }
                if not ok then
                    ngx.say('failed connected to mysql',err)
                    return
                else
                    ngx.say('mysql connected success'..'<br/>')
                end
                db:set_timeout(1000)
                -- local sql = "insert into users (username,birthday,salary) values ('aris','1998-12-07',22356)"
                -- local sql = "update users set salary=100 where id=1"
                local sql = "delete from users where username = 'aris'"
            	# 使用query()
                local res,err,errcode,sqlstate = db:query(sql)
                if res then
                    local res_json = cjson.encode(res)
                    ngx.say('res_json: ',res_json)
                    ngx.say('<br/>')
                end
                ngx.say('err:',err)
                ngx.say('<br/>')
                ngx.say('errcode:',errcode)
                ngx.say('<br/>')
                ngx.say('sqlstate:',sqlstate)
                db:close()
            }
        }

验证结果

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-- 新增
insert into users (username,birthday,salary) values ('aris','1998-12-07',22356)

image-20220609033006008

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-- 修改
update users set salary=100 where id=1

image-20220609033232697

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-- 删除
delete from users where username = 'aris'

image-20220609033404049

ngx_lua缓存预热

需求

使用ngx_lua做缓存预热. 访问路径http://192.168.253.138/cacheWarm?username=Tom, 不带参数时, 将所有数据缓存进Redis, 带参数时, 仅更新一条

修改配置

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$ sudo mkdie /usr/local/openresty/nginx/lua_script
$ sudo vim /usr/local/openresty/nginx/lua_script/lua_init_script.lua
$ sudo vim /usr/local/openresty/nginx/lua_script/lua_cache_warm_script.lua 
$ sudo vim /usr/local/openresty/nginx/conf/nginx.conf
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# 修改Nginx配置文件
# sudo vim /usr/local/openresty/nginx/conf/nginx.conf
http {
	...
    init_by_lua_file /usr/local/openresty/nginx/lua_script/init_script.lua;
	...
   	server {
		...
        location /cacheWarm{
            default_type 'text/html';
            content_by_lua_file /usr/local/openresty/nginx/lua_script/lua_cache_warm_script.lua;
        }
    }
}
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-- 创建初始化脚本
-- sudo vim /usr/local/openresty/nginx/lua_script/lua_init_script.lua
redis = require 'resty.redis'
mysql = require 'resty.mysql'
cjson = require 'cjson'
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-- 创建业务逻辑脚本
-- sudo vim /usr/local/openresty/nginx/lua_script/lua_cache_warm_script.lua 
-- 获取get参数username
local param = ngx.req.get_uri_args()['username'];

-- 连接数据库
local db = mysql:new()
local ok,err = db:connect{
	host="192.168.253.134",
	port=3306,
	user="root",
	password="xxxxxx",
	database="nginx_db"
}
if not ok then
	ngx.say("failed connect to mysql: ",err)
	return
end
db:set_timeout(1000)

-- 依据get参数构建SQL
local sql = ""
if param then
	sql = "select * from users where username = ".."'"..param.."'"
else
	sql = "select * from users"
end

--执行SQL,获取数据
local res,err,errcode,sqlstate = db:query(sql)
if not res then
	ngx.say("failed query in mysql: ",err)
	return
end

-- 连接Redis
local redisObj = redis:new()
local ok,err = redisObj:connect("192.168.253.135",6379)
if not ok then
	ngx.say("failed connect to redis: ",err)
	return
end
redisObj:set_timeout(1000)

-- 循环MySQL数据存入Redis
local count=0
for i,v in ipairs(res) do
	local redis_key = "user_"..v.username
	local res_json = cjson.encode(v)
	local ok,err = redisObj:set(redis_key,res_json)
	if not ok then
		ngx.say("failed set redis value: "..redis_key..'-'..res_json,err)
	else
		ngx.say("success set redis value: "..redis_key..'-'..res_json)
	end
	ngx.say("<br/>")
	count = count + 1
end
ngx.say("warm cache success, total count "..count)

-- 关闭连接
db:close()
redisObj:close()

访问结果

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访问 http://192.168.253.138/cacheWarm

image-20220609041921037

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访问http://192.168.253.138/cacheWarm?username=Tom

image-20220609041936691

查看Redis缓存结果

image-20220609043004337