使用场景： 客户只要通过后台绑定了自己的域名，解析到我们服务器之后。就能通过绑定的域名类型访问到相应的对应资源。实现原理是：在绑定的时候程序会将绑定域名和类型写入到redis中，并永久保存，NGINX通过lua读取redis里面的数据，指定不同的root路径。

安装

• 安装luajit

yum -y install lua lua-devel  ## 编译的时候会依赖这个
cd /opt && wget http://luajit.org/download/LuaJIT-2.0.5.tar.gz
tar zxvf LuaJIT-2.0.5.tar.gz && cd LuaJIT-2.0.5
make install PREFIX=/opt/luajit
export LUAJIT_LIB=/opt/luajit/lib   ## 编译nginx需要的变量
export LUAJIT_INC=/opt/luajit/include/luajit-2.0  ## 编译nginx需要的变量

• 安装cjson库，用来解析json格式数据的

cd /opt && wget https://www.kyne.com.au/~mark/software/download/lua-cjson-2.1.0.tar.gz
tar zxvf lua-cjson-2.1.0.tar.gz && cd lua-cjson-2.1.0
##编辑Makefile修改以下几个参数
vim Makefile
PREFIX =            /opt/luajit
LUA_INCLUDE_DIR =   /opt/luajit/include/luajit-2.0
LUA_CMODULE_DIR =   /opt/luajit/lib
LUA_MODULE_DIR =    /opt/luajit/share/lua/5.1
LUA_BIN_DIR =       /opt/luajit/bin
##编译并安装
make && make install

• 安装cmsgpack库，主要用来序列化和反序列化的

cd /opt && git clone https://github.com/antirez/lua-cmsgpack.git && cd /opt/lua-cmsgpack
mkdir build && cd build && cmake .. && make

• nginx编译需要的模块

cd /opt && git clone https://github.com/simplresty/ngx_devel_kit.git
cd /opt && git clone https://github.com/openresty/lua-nginx-module.git
cd /opt && git clone https://github.com/openresty/lua-resty-redis.git

• 解决一些模块和库文件依赖问题

cp /opt/lua-cmsgpack/build/cmsgpack.so /opt/luajit/lib/
cp /opt/lua-cmsgpack/build/cmsgpack.so /opt/luajit/lib/lua/5.1/
cp /opt/luajit/lib/cjson.so /opt/luajit/lib/lua/5.1/
echo "/usr/local/lib/" >> /etc/ld.so.conf.d/libc.conf
echo "/opt/luajit/lib" >> /etc/ld.so.conf.d/libc.conf
ldconfig

• 编译nginx,复制编译好的nginx二进制文件替换原来的nginx(原来的nginx二进制文件做备份)

tar zxvf nginx-1.14.0.tar.gz && cd nginx-1.14.0
./configure --add-module=/opt/lua-nginx-module --add-module=/opt/ngx_devel_kit --prefix=/opt/nginx --user=nginx --group=nginx --with-http_ssl_module --with-http_dav_module --with-http_flv_module --with-http_realip_module --with-http_addition_module --with-http_xslt_module --with-http_stub_status_module --with-http_sub_module --with-http_random_index_module --with-http_degradation_module --with-http_secure_link_module --with-http_gzip_static_module --with-http_perl_module --with-pcre --with-debug --with-file-aio --with-mail --with-mail_ssl_module --with-stream --with-ld-opt=-Wl,-E
make -j2

下面是一个示例代码

• 在nginx.conf中http下加入redis的支持: “lua_package_path “/opt/lua-resty-redis/lib/?.lua;;”;”
• lua.conf的配置文件如下：

server {
    listen 80 default;
    server_name _;  ## 这儿做默认解析
    access_log  logs/lua.log;
    error_log  logs/lua.error.log;
    index index.html;

    location / {
        add_header 'Access-Control-Allow-Origin' '*';
        set $defaultroot /opt/web/default;
        access_by_lua_file '/opt/nginx/conf/vhost/lua.lua';
        root $defaultroot;
        try_files $uri $uri/ /index.html;
    }

• lua.lua的配置文件如下：

local redis = require "resty.redis"
local cjson = require "cjson"
local cmsgpack  = require "cmsgpack" 

local red = redis:new()
red:set_timeout(1000)
local ok, err = red:connect("127.0.0.1", 6379)
if not ok then
   ngx.say("failed to connect: ", err)
   return
end
red:select(1)

local redisData = red:get("domain.key")
local getdata = cjson.decode(redisData);

for i,w in ipairs(getdata) do
     if ngx.var.host == w.domain
          then
          if w.type == "app1"
          then
               ngx.var.defaultroot = "/opt/web/app1"
          elseif w.type == "app2"
          then
               ngx.var.defaultroot = "/opt/web/app2"
          else
               ngx.var.defaultroot = "/opt/web/default"
          end
     end
end
red:close()

• redis中取出来的json格式如下：

[
  {
    "domain":"domain1_name",
    "id":"123456",
    "type":"app1"
  },
  {
    "domain":"domain2_name",
    "id":"123457",
    "type":"app2"
  },
  {
    "domain":"domain3_name",
    "id":"123458",
    "type":"app3"
  }
]