項目github地址:點擊跳轉
場景痛點
在Spring Cloud微服務架構體系中,我們往往會部署一個Zuul集羣來橫向擴展我們的微服務應用,集羣的上層是Nginx軟負載,在實際情況中,往往會遇到Zuul宕機的尷尬事情,這時候從Nginx到這臺機器的請求就會全部失效。此項目針對此痛點,用lua腳本實現定時拉取特定服務地址,動態無感知增減Zuul在Nginx中的負載節點。
如果您希望實現從Nginx直接到普通服務的動態節點負載,在下文配置服務名與Eureka註冊中心地址即可。
OpenResty安裝與配置
1、環境
yum -y install readline-devel pcre-devel openssl-devel gcc
2、下載解壓OpenResty包
wget https://openresty.org/download/openresty-1.13.6.1.tar.gz
tar -zxvf openresty-1.13.6.1.tar.gz
3、下載ngx_cache_purge模塊,該模塊用於清理nginx緩存
cd openresty-1.13.6.1/bundle
wget http://labs.frickle.com/files/ngx_cache_purge-2.3.tar.gz
tar -zxvf ngx_cache_purge-2.3.tar.gz
4、下載nginx_upstream_check_module模塊,該模塊用於upstream健康檢查
wget https://github.com/yaoweibin/nginx_upstream_check_module/archive/v0.3.0.tar.gz
tar -zxvf v0.3.0.tar.gz
5、OpenResty配置增加
cd openresty-1.13.6.1
./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
6、編譯安裝
make
make install
7、OpenResty沒有http模塊,需要單獨安裝
cd /usr/servers/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
8、項目腳本拷貝到這裏
copy dynamic_eureka_balancer.lua into this dir
9、Nginx配置文件
vim /usr/servers/nginx/conf/nginx.conf
Nginx配置
http {
#sharing cache area
lua_shared_dict dynamic_eureka_balancer 128m;
init_worker_by_lua_block {
-- init eureka balancer
local file = require "resty.dynamic_eureka_balancer"
local balancer = file:new({dict_name="dynamic_eureka_balancer"})
--eureka server list
balancer.set_eureka_service_url({"127.0.0.1:8888", "127.0.0.1:9999"})
--The service name that needs to be monitored
balancer.watch_service({"zuul", "client"})
}
upstream springcloud_cn {
server 127.0.0.1:666; # Required, because empty upstream block is rejected by nginx (nginx+ can use 'zone' instead)
balancer_by_lua_block {
--The zuul name that needs to be monitored
local service_name = "zuul"
local file = require "resty.dynamic_eureka_balancer"
local balancer = file:new({dict_name="dynamic_eureka_balancer"})
--balancer.ip_hash(service_name) --IP Hash LB
balancer.round_robin(service_name) --Round Robin LB
}
}
server {
listen 80;
server_name localhost;
location / {
proxy_pass http://springcloud_cn/;
proxy_set_header Host $http_host;
proxy_set_header X-Real-IP $remote_addr;
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header X-Forwarded-Proto $scheme;
}
error_page 500 502 503 504 /50x.html;
location = /50x.html {
root html;
}
}
}