OpenResty部署nginx及nginx+lua

因为用nginx+lua去开发,所以会选择用最流行的开源方案,就是用OpenResty

nginx+lua打包在一起,而且提供了包括redis客户端,mysql客户端,http客户端在内的大量的组件

1、部署第一个nginx,作为应用层nginx

(1)部署openresty

mkdir -p /usr/servers  
cd /usr/servers/

yum install -y readline-devel pcre-devel openssl-devel gcc

wget http://openresty.org/download/ngx_openresty-1.7.7.2.tar.gz  
tar -xzvf ngx_openresty-1.7.7.2.tar.gz  
cd /usr/servers/ngx_openresty-1.7.7.2/

cd bundle/LuaJIT-2.1-20150120/  
make clean && make && make install  
ln -sf luajit-2.1.0-alpha /usr/local/bin/luajit

cd bundle  
wget https://github.com/FRiCKLE/ngx_cache_purge/archive/2.3.tar.gz  
tar -xvf 2.3.tar.gz  

cd bundle  
wget https://github.com/yaoweibin/nginx_upstream_check_module/archive/v0.3.0.tar.gz  
tar -xvf v0.3.0.tar.gz  

cd /usr/servers/ngx_openresty-1.7.7.2  
./configure --prefix=/usr/servers --with-http_realip_module  --with-pcre  --with-luajit --add-module=./bundle/ngx_cache_purge-2.3/ --add-module=./bundle/nginx_upstream_check_module-0.3.0/ -j2  
make && make install 

cd /usr/servers/  
ll

/usr/servers/luajit
/usr/servers/lualib
/usr/servers/nginx
/usr/servers/nginx/sbin/nginx -V 

启动nginx: /usr/servers/nginx/sbin/nginx

  

(2)nginx+lua开发的hello world

vi /usr/servers/nginx/conf/nginx.conf

在http部分添加:

lua_package_path "/usr/servers/lualib/?.lua;;";  
lua_package_cpath "/usr/servers/lualib/?.so;;";  

/usr/servers/nginx/conf下,创建一个lua.conf

server {  
    listen       80;  
    server_name  _;  
}  

在nginx.conf的http部分添加:

include lua.conf;

验证配置是否正确:

/usr/servers/nginx/sbin/nginx -t

在lua.conf的server部分添加:

location /lua {  
    default_type 'text/html';  
    content_by_lua 'ngx.say("hello world")';  
} 

/usr/servers/nginx/sbin/nginx -t  

重新nginx加载配置

/usr/servers/nginx/sbin/nginx -s reload  

访问http: http://192.168.31.187/lua

vi /usr/servers/nginx/conf/lua/test.lua

ngx.say("hello world"); 

修改lua.conf

location /lua {  
    default_type 'text/html';  
    content_by_lua_file conf/lua/test.lua; 
}

  

查看异常日志

tail -f /usr/servers/nginx/logs/error.log

(3)工程化的nginx+lua项目结构

项目工程结构

hello
    hello.conf     
    lua              
      hello.lua
    lualib            
      *.lua
      *.so

放在/usr/hello目录下

/usr/servers/nginx/conf/nginx.conf

worker_processes  2;  

error_log  logs/error.log;  

events {  
    worker_connections  1024;  
}  

http {  
    include       mime.types;  
    default_type  text/html;  
  
    lua_package_path "/usr/hello/lualib/?.lua;;";  
    lua_package_cpath "/usr/hello/lualib/?.so;;"; 
    include /usr/hello/hello.conf;  
}  

/usr/hello/hello.conf

server {  
    listen       80;  
    server_name  _;  
  
    location /lua {  
        default_type 'text/html';  
        lua_code_cache off;  
        content_by_lua_file /usr/example/lua/test.lua;  
    }  
}  

  用eshop-cache01和eshop-cache02作为应用层nginx服务器,用eshop-cache03作为分发层nginx

在eshop-cache03,也就是分发层nginx中,编写lua脚本,完成基于商品id的流量分发策略

步骤:

1、获取请求参数,比如productId

2、对productId进行hash

3、hash值对应用服务器数量取模,获取到一个应用服务器

4、利用http发送请求到应用层nginx

5、获取响应后返回

作为一个流量分发的nginx,会发送http请求到后端的应用nginx上面去,所以要先引入lua http lib包

cd /usr/hello/lualib/resty/  
wget https://raw.githubusercontent.com/pintsized/lua-resty-http/master/lib/resty/http_headers.lua  
wget https://raw.githubusercontent.com/pintsized/lua-resty-http/master/lib/resty/http.lua 

  代码:

 

local uri_args = ngx.req.get_uri_args()
local productId = uri_args["productId"]

local hosts = {"192.168.31.187", "192.168.31.19"}
local hash = ngx.crc32_long(productId)
local index = (hash % 2) + 1
backend = "http://"..hosts[index]

local requestPath = uri_args["requestPath"]
requestPath = "/"..requestPath.."?productId="..productId

local http = require("resty.http")
local httpc = http.new()

local resp, err = httpc:request_uri(backend,{
  method = "GET",
  path = requestPath
})

if not resp then
  ngx.say("request error: ", err)
  return
end

ngx.say(resp.body)

httpc:close()

  

分发层nginx,lua应用,会将商品id,商品店铺id,都转发到后端的应用nginx

位置:/usr/servers/nginx/sbin/nginx -s reload

 

1、应用nginx的lua脚本接收到请求

2、获取请求参数中的商品id,以及商品店铺id

3、根据商品id和商品店铺id,在nginx本地缓存中尝试获取数据

4、如果在nginx本地缓存中没有获取到数据,那么就到redis分布式缓存中获取数据,如果获取到了数据,还要设置到nginx本地缓存中

但是这里有个问题,建议不要用nginx+lua直接去获取redis数据

因为openresty没有太好的redis cluster的支持包,所以建议是发送http请求到缓存数据生产服务,由该服务提供一个http接口

缓存数生产服务可以基于redis cluster api从redis中直接获取数据,并返回给nginx

cd /usr/hello/lualib/resty/  
wget https://raw.githubusercontent.com/pintsized/lua-resty-http/master/lib/resty/http_headers.lua  
wget https://raw.githubusercontent.com/pintsized/lua-resty-http/master/lib/resty/http.lua 

  

5、如果缓存数据生产服务没有在redis分布式缓存中没有获取到数据,那么就在自己本地ehcache中获取数据,返回数据给nginx,也要设置到nginx本地缓存中

6、如果ehcache本地缓存都没有数据,那么就需要去原始的服务中拉去数据,该服务会从mysql中查询,拉去到数据之后,返回给nginx,并重新设置到ehcache和redis中

7、nginx最终利用获取到的数据,动态渲染网页模板

cd /usr/hello/lualib/resty/
wget https://raw.githubusercontent.com/bungle/lua-resty-template/master/lib/resty/template.lua
mkdir /usr/hello/lualib/resty/html
cd /usr/hello/lualib/resty/html
wget https://raw.githubusercontent.com/bungle/lua-resty-template/master/lib/resty/template/html.lua

  在hello.conf的server中配置模板位置

set $template_location "/templates";  
set $template_root "/usr/hello/templates";

mkdir /usr/hello/templates

vi product.html

product id: {* productId *}<br/>
product name: {* productName *}<br/>
product picture list: {* productPictureList *}<br/>
product specification: {* productSpecification *}<br/>
product service: {* productService *}<br/>
product color: {* productColor *}<br/>
product size: {* productSize *}<br/>
shop id: {* shopId *}<br/>
shop name: {* shopName *}<br/>
shop level: {* shopLevel *}<br/>
shop good cooment rate: {* shopGoodCommentRate *}<br/>

  

8、将渲染后的网页模板作为http响应,返回给分发层nginx

hello.conf中:

lua_shared_dict my_cache 128m;

  lua脚本中:

local uri_args = ngx.req.get_uri_args()
local productId = uri_args["productId"]
local shopId = uri_args["shopId"]

local cache_ngx = ngx.shared.my_cache

local productCacheKey = "product_info_"..productId
local shopCacheKey = "shop_info_"..shopId

local productCache = cache_ngx:get(productCacheKey)
local shopCache = cache_ngx:get(shopCacheKey)

if productCache == "" or productCache == nil then
        local http = require("resty.http")
        local httpc = http.new()

        local resp, err = httpc:request_uri("http://192.168.31.179:8080",{
                method = "GET",
                path = "/getProductInfo?productId="..productId
        })

        productCache = resp.body
        cache_ngx:set(productCacheKey, productCache, 10 * 60)
end

if shopCache == "" or shopCache == nil then
        local http = require("resty.http")
        local httpc = http.new()

        local resp, err = httpc:request_uri("http://192.168.31.179:8080",{
                method = "GET",
                path = "/getShopInfo?shopId="..shopId
        })

        shopCache = resp.body
        cache_ngx:set(shopCacheKey, shopCache, 10 * 60)
end

local cjson = require("cjson")
local productCacheJSON = cjson.decode(productCache)
local shopCacheJSON = cjson.decode(shopCache)

local context = {
        productId = productCacheJSON.id,
        productName = productCacheJSON.name,
        productPrice = productCacheJSON.price,
        productPictureList = productCacheJSON.pictureList,
        productSpecification = productCacheJSON.specification,
        productService = productCacheJSON.service,
        productColor = productCacheJSON.color,
        productSize = productCacheJSON.size,
        shopId = shopCacheJSON.id,
        shopName = shopCacheJSON.name,
        shopLevel = shopCacheJSON.level,
        shopGoodCommentRate = shopCacheJSON.goodCommentRate
}

local template = require("resty.template")
template.render("product.html", context)

  

第一次访问的时候,其实在nginx本地缓存中是取不到的,所以会发送http请求到后端的缓存服务里去获取,会从redis中获取

拿到数据以后,会放到nginx本地缓存里面去,过期时间是10分钟

然后将所有数据渲染到模板中,返回模板

以后再来访问的时候,就会直接从nginx本地缓存区获取数据了

缓存数据生产 -> 有数据变更 -> 主动更新两级缓存(ehcache+redis)-> 缓存维度化拆分

分发层nginx + 应用层nginx -> 自定义流量分发策略提高缓存命中率

nginx shared dict缓存 -> 缓存服务 -> redis -> ehcache -> 渲染html模板 -> 返回页面

如果你的数据在nginx -> redis -> ehcache三级缓存都不在了,可能就是被LRU清理掉了

这个时候缓存服务会重新拉去数据,去更新到ehcache和redis中