nginx_lua模块基于mysql数据库动态修改网页内容

最近要实现一个需求，根据查询mysql数据库返回的内容，插入到网页底部。目前前端是用varnish作的缓存，刚开始想从varnish下手，但官方varnish不支持修改网页内容，要支持的话还需要自己修改源码实现，这个有点难度放弃了，于是想在varnish的后端架设一台nginx的反向代理服务器获取网页内容，然后通过nginx_lua模块实现查询mysql数据库动态修改网页的功能。下面是使用nginx_lua模块的方法，记录一下方便下次查询。

安装luajit2.0

git的安装可以参考：https://www.centos.bz/2012/09/centos-install-git/

cd /tmp/
git clone http://luajit.org/git/luajit-2.0.git
cd luajit-2.0/
make && make install
ln -sf luajit-2.0.0-beta10 /usr/local/bin/luajit
ln -sf /usr/local/lib/libluajit-5.1.so.2 /usr/lib/

下载ngx_devel_kit、lua-nginx-module和nginx

cd /tmp
git clone http://github.com/simpl/ngx_devel_kit.git
git clone http://github.com/chaoslawful/lua-nginx-module.git
wget http://nginx.org/download/nginx-1.2.3.tar.gz

安装nginx

tar xzf nginx-1.2.3.tar.gz
cd nginx-1.2.3
export LUAJIT_LIB=/usr/local/lib
export LUAJIT_INC=/usr/local/include/luajit-2.0
./configure --prefix=/usr/local/nginx --add-module=/tmp/ngx_devel_kit --add-module=/tmp/lua-nginx-module
make && make install

安装lua-resty-mysql

cd /tmp
git clone http://github.com/agentzh/lua-resty-mysql.git
cd lua-resty-mysql/
make install

nginx配置文件

server {
......
......
resolver 8.8.8.8;
location / {
default_type text/html;
content_by_lua_file "/usr/local/nginx/conf/lua";
}
location /proxy {
internal;
proxy_pass $scheme://$http_host$request_uri;
proxy_set_header Accept-Encoding '';
proxy_redirect off;
}
......
......
}

lua内容

if (ngx.req.get_method()=="GET") then
data=ngx.location.capture("/proxy")
if data.status == 200 then
if data.header["Content-Type"] and string.find(data.header["Content-Type"],"html") then
--mysql connect begin
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) -- 1 sec
ok, err, errno, sqlstate = db:connect{
host = "127.0.0.1",
port = 3306,
database = "proxy",
user = "root",
password = "537817",
compact_arrays=true,
max_packet_size = 1024 * 1024 }
if not ok then
ngx.say("failed to connect: ", err, ": ", errno, " ", sqlstate)
return
end
host=ngx.req.get_headers()["Host"]
"..host.."'"
res, err, errno, sqlstate = db:query(sql)
if not res then
ngx.say("bad result: ", err, ": ", errno, ": ", sqlstate, ".")
return
end
--mysql connect end
if table.getn(res)==0 then
for k,v in pairs(data.header) do
ngx.header[k]=v
end
ngx.say(data.body)
else
for k,v in pairs(data.header) do
if (k=="Content-Length") then
ngx.header["Content-Length"]=""
else
ngx.header[k]=v
end
end
body,_=string.gsub(data.body,"</body>",res[1][1].."</body>")
ngx.say(body)
end
else
for k,v in pairs(data.header) do
ngx.header[k]=v
end
ngx.say(data.body)
end;
else
ngx.exec("/proxy")
end;
else
ngx.exec("/proxy");
end;