OpenResty(nginx)操做mysql的初步应用

OpenResty （也称为 ngx_openresty）是一个全功能的 Web 应用服务器，它打包了标准的 Nginx 核心，不少的经常使用的第三方模块，以及它们的大多数依赖项。

OpenResty 经过汇聚各类设计精良的 Nginx 模块, 从而将 Nginx 有效的变成一个强大的 Web 应用服务器, 这样, Web 开发人员可使用 Lua 脚本语言调动 Nginx 支持的各类C以及Lua 模块, 快速构造出足以胜任 10K+ 并发链接响应的超高性能Web 应用系统.

OpenResty 的目标是让你的Web服务直接跑在 Nginx 服务内部, 充分利用 Nginx 的非阻塞 I/O 模型, 不单单对 HTTP 客户端请求,甚至于对远程后端诸如 MySQL,PostgreSQL,~Memcaches 以及 ~Redis 等都进行一致的高性能响应.

OpenResty 英文官网：http://openresty.org/

OpenResty 中文官网：http://openresty.org/cn/

Nginx 维基官网：http://wiki.nginx.org/

说明：

OpenResty的安装比较简单，这里要使用一个强大的功能，就是用nginx直接访问mysql，取出数据，返回给浏览器，有两种方法，第一种：使用 HttpDrizzleModule 模块，同时还须要安装 libdrizzle 1.0(在drizzle里)，第二种：使用ngx_lua模块和lua库lua-resty-mysql(Mysql client Driver)。默认安装OpenResty时，还有一些lua库被安装，如 mysql.lua、redis.lua、upload.lua、memcached.lua、aes.lua、md5.lua、cjson.so等等。

不管使用何种方法，都须要安装 pcre 库 libpcre，这是安装nginx必须的

[root@vm5 ~]# yum install pcre-devel.x86_64

方法一

一、安装 libdrizzle 1.0

[root@vm5 ~]# wget http://agentzh.org/misc/nginx/drizzle7-2011.07.21.tar.gz
[root@vm5 ~]# tar zxvf drizzle7-2011.07.21.tar.gz
[root@vm5 ~]# cd drizzle7-2011.07.21
[root@vm5 drizzle7-2011.07.21]# ./configure --without-server
[root@vm5 drizzle7-2011.07.21]# make libdrizzle-1.0
[root@vm5 drizzle7-2011.07.21]# make install-libdrizzle-1.0

二、安装  OpenResty

[root@vm5 ~]# wget http://openresty.org/download/ngx_openresty-1.2.4.14.tar.gz
[root@vm5 ~]# tar zxvf ngx_openresty-1.2.4.14.tar.gz
[root@vm5 ~]# cd ngx_openresty-1.2.4.14
[root@vm5 ngx_openresty-1.2.4.14]# ./configure --prefix=/usr/local/openresty --with-luajit --with-http_drizzle_module --with-libdrizzle=/usr/local
[root@vm5 ngx_openresty-1.2.4.14]# gmake
[root@vm5 ngx_openresty-1.2.4.14]# gmake install

三、建立测试数据

mysql> create table users(id int,username varchar(30),age tinyint);
Query OK, 0 rows affected (0.00 sec)

mysql> insert into users values(1, 'zhangsan',24);
Query OK, 1 row affected (0.00 sec)

mysql> insert into users values(2, 'lisi',26);
Query OK, 1 row affected (0.00 sec)

四、编辑 nginx.conf 配置文件

worker_processes 1;
events {
        worker_connections 1024;
}
http {
        include mime.types;
        default_type application/octet-stream;
        sendfile on;
        keepalive_timeout 65;
         upstream mysql {
                drizzle_server 127.0.0.1:3306 dbname=test user=root protocol=mysql;
        }
        server {
                listen 80;
                server_name localhost;
                root html;
                index index.html index.htm;
                 location = /mysql-status {
                        drizzle_status;
                }
                location / {
                         drizzle_pass mysql;
                        drizzle_query "select id,username,age from users where id=1";
                        rds_json on;
                }
                error_page 500 502 503 504 /50x.html;
                location = /50x.html {
                        root html;
                }
        }
}

红色的配置用到了 HttpDrizzleModule 和 rds-json-nginx-module 模块，前一个模块是用来和数据库交互的，后面那个是作数据格式转换的，这里使用的是 json 数据格式

五、测试配置文件、启动 nginx

[root@vm5 conf]# /usr/local/openresty/nginx/sbin/nginx -t -c /usr/local/openresty/nginx/conf/nginx.conf
nginx: the configuration file /usr/local/openresty/nginx/conf/nginx.conf syntax is ok
nginx: configuration file /usr/local/openresty/nginx/conf/nginx.conf test is successful
[root@vm5 conf]# /usr/local/openresty/nginx/sbin/nginx -c /usr/local/openresty/nginx/conf/nginx.conf
[root@vm5 conf]# netstat -ntupl
Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address Foreign Address State PID/Program name
tcp 0 0 0.0.0.0:3306 0.0.0.0:* LISTEN 28013/mysqld
tcp 0 0 0.0.0.0:80 0.0.0.0:* LISTEN 28036/nginx.conf
tcp 0 0 :::22 :::* LISTEN 2901/sshd

六、测试

[root@vm5 nginx]# curl localhost
[{"id":1,"username":"zhangsan","age":24}]
[root@vm5 nginx]# curl localhost/mysql-status
worker process: 29491

upstream mysql
    active connections: 0
    connection pool capacity: 0
    servers: 1
    peers: 1

ok，效果出来了，直接用 nginx 去读 mysql 数据，并且输出的数据格式是json格式的，可用ajax折腾，并且能够web查看mysql状态，是否是很牛X啊！

再来一个能够传id参数的例子：

修改 nginx 配置文件 nginx.conf

drizzle_query "select id,username,age from users where id=$arg_id";

测试

[root@vm5 nginx]# curl localhost/?id=1
[{"id":1,"username":"zhangsan","age":24}]
[root@vm5 nginx]# curl localhost/?id=2
[{"id":2,"username":"lisi","age":26}]

ok，能够接收参数了，可是这么配置存在一个bug，那就是没有传递参数时会报错，这只是一个测试用例，要想在线上使用须要完善它。另外若是在前面例子中不使用rds_json指令转换输出格式的话，默认输出的是二进制格式(application/x-resty-dbd-stream )，显示在终端窗口时可能显示数据不全，能够将输出定向到一个文件，用vim查看，能够看到完整数据。通常都是配合json、csv格式使用。

方法二

一、修改 nginx 配置文件 nginx.conf

worker_processes    1;
events {
        worker_connections    1024;
}
http {
        include             mime.types;
        default_type    application/octet-stream;
        sendfile                on;
        keepalive_timeout    65;
        server {
                listen             80;
                server_name    localhost;
                root     html;
                index    index.html index.htm;
                location / {
                        content_by_lua '
                                local mysql = require "resty.mysql"
                                local db,err = mysql:new()
                                if not db then
                                        ngx.say("failed to instantiate mysql: ",err)
                                        return
                                end

                                db:set_timeout(1000)
 
                                local ok,err,errno,sqlstate = db:connect{
                                        host = "127.0.0.1",
                                        port = 3306,
                                        database = "test",
                                        user = "root",
                                        password = "",
                                        max_package_size = 1024
                                }
                                if not ok then
                                        ngx.say("failed to connect: ", err, ": ", errno, " ", sqlstate)
                                        return
                                end

                                res,err,errno,sqlstate = db:query("select id,username,age from users where id=1")
                                if not res then
                                        ngx.say("bad result: ", err, ": ", errno, ": ", sqlstate, ".")
                                        return
                                end

                                local cjson = require "cjson"
                                ngx.say(cjson.encode(res))
                        ';
                }
                error_page     500 502 503 504    /50x.html;
                location = /50x.html {
                        root     html;
                }
        }
}

或者也能够将上面的lua代码放到一个以.lua为扩展名的文件里，并在nginx.conf里使用content_by_lua_file指令引用

步骤以下：

[root@vm5 lua]# mkdir /usr/local/openresty/nginx/conf/lua
[root@vm5 lua]# touch /usr/local/openresty/nginx/conf/lua/mysql.lua

将上面content_by_lua指令所指的代码加入到mysql.lua文件里，并在nginx.conf里引用以下：

content_by_lua_file conf/lua/mysql.lua;

便可

二、测试配置文件、重启 nginx 服务

[root@vm5 conf]# /usr/local/openresty/nginx/sbin/nginx -t -c /usr/local/openresty/nginx/conf/nginx.conf
nginx: the configuration file /usr/local/openresty/nginx/conf/nginx.conf syntax is ok
nginx: configuration file /usr/local/openresty/nginx/conf/nginx.conf test is successful
[root@vm5 conf]# killall -HUP nginx

三、测试

[root@vm5 conf]# curl localhost
[{"username":"zhangsan","age":24,"id":1}]

ok，输出json格式数据了，结果也是对的。赞一个！

咱们稍做修改，使其支持传递 id 参数

修改 nginx 配置文件

res,err,errno,sqlstate = db:query("select id,username,age from users where id="..ngx.var.arg_id)

测试配置、重启服务，略

测试结果

[root@vm5 conf]# curl localhost/?id=2
[{"username":"lisi","age":26,"id":2}]
[root@vm5 conf]# curl localhost/?id=1
[{"username":"zhangsan","age":24,"id":1}]

再一次ok，效果不错吧！

注意：以上代码要想用在生产环境，还须要添加一些错误捕获代码！

这里有些代码是参照官网上的，详情能够查阅官网。