采用ubuntu系統，docker安裝自行百度

1.安裝tomcat

docker run -d -p 8088:8080 tomcat
docker run -d -p 8089:8080 tomcat

安裝兩個實例，端口分別為8088,8089

2.安裝nginx

docker run -p 8080:80 -d docker.io/nginx

安裝nginx，端口為8080。在測試的過程中，發現ubuntu上對80端口有限制，不能直接訪問，所以映射為8080

3.修改nginx配置

3.1查看實例

    sudo docker ps
    CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                               NAMES
    516b1562b0e3        nginx               
 
"nginx -g ‘daemon of…"   21 minutes ago      Up 2 minutes        0.0.0.0:8080->80/tcp                musing_dewdney
    36e48585253f        tomcat              "catalina.sh run"        About an hour ago   Up About an hour    0.0.0.0:8089->8080/tcp              keen_wescoff
    7eb77e6a33e5        tomcat              
 
"catalina.sh run"        About an hour ago   Up About an hour    0.0.0.0:8088->8080/tcp              frosty_grothendieck
    2069f54ea331        mysql:5.7           "docker-entrypoint.s…"   3 hours ago         Up 3 hours          0.0.0.0:3306->3306/tcp, 33060/tcp   mysqltest

3.2進入nginx的bash

sudo docker exec -it 516b1562b0e3 bash

3.3修改配置

#user  nobody;
worker_processes  1;

#error_log  logs/error.log;
#error_log  logs/error.log  notice;
#error_log  logs/error.log  info;

#pid        logs/nginx.pid;


events {
    worker_connections  1024;
}


http {
    include       mime.types;
    default_type  application/octet-stream;

    proxy_buffer_size 128k;
    proxy_buffers 32 128k;
    proxy_busy_buffers_size 128k;


    sendfile        on;
    #tcp_nopush     on;

    #keepalive_timeout  0;
    keepalive_timeout  65;

    #gzip  on;

    # 註意，這裏的server名字即org.tonny.balance不能帶下劃線，tomcat是上面安裝的tomcat
    upstream org.tonny.balance {
        server 192.168.126.128:8088 weight=1;
        server 192.168.126.128:8089 weight=1;
    }

    server {
        #註意，這裏保留80，因為前面的docker運行命令，會映射80端口
        listen       80;
        server_name  localhost;

        #charset koi8-r;

        #access_log  logs/host.access.log  main;

        # 不帶數據的請求
        location / {
            root   html;
            index  index.html index.htm;
            #訪問映射
            proxy_pass   http://org.tonny.balance; 
        }

        #error_page  404              /404.html;

        # redirect server error pages to the static page /50x.html
        #
        error_page   500 502 503 504  /50x.html;
        location = /50x.html {
            root   html;
        }
    }
}

3.4重啟nginx

sudo docker restart 516b1562b0e3

4.測試

通過ip,端口訪問即可

docker上配置nginx負載均衡