docker实现nginx+tomcat负载均衡集群

集群结构：

1、创建网络br1
#docker network create --driver=bridge br1

2、创建网页根目录，并把需要展示的网页放到目录内
#mkdir -p /webapps/ROOT 
#echo "test tomcat" >/webapps/ROOT/index.html

3、运行三个tomcat容器实例
#docker run -itd --name tomcat1 --net br1 -v /webapps/ROOT:/usr/local/tomcat/webapps/ROOT tomcat
#docker run -itd --name tomcat2 --net br1 -v /webapps/ROOT:/usr/local/tomcat/webapps/ROOT tomcat
#docker run -itd --name tomcat3 --net br1 -v /webapps/ROOT:/usr/local/tomcat/webapps/ROOT tomcat

4、创建nginx配置目录并修改nginx配置文件
#mkdir  /nginx
[root@node4 ROOT]# grep -Ev "^#|^[[:space:]]*#|^$" /nginx/default.conf
upstream tomcatcluster {
        server tomcat1:8080;
        server tomcat2:8080;
        server tomcat3:8080;
}
server {
    listen       80;
    server_name  localhost;
    location / {

proxy_pass http://tomcatcluster;
   }
    error_page   500 502 503 504  /50x.html;
    location = /50x.html {
        root   /usr/share/nginx/html;
    }
}

5、运行nginx容器
#docker run --name nginx --net br1 -itd -p 80:80 -v /nginx:/etc/nginx/conf.d nginx