docker nginx:

docker run -d \
        --hostname nginx \
        --name nginx \
        -p 80:80 -p 443:443 \
        --restart always \
        --volume /data/nginx/config:/opt/bitnami/nginx/conf/bitnami \
        bitnami/nginx:1.9.15-1


bitnami.conf:
server {
        listen 80;
        server_name oa.myweb.cn;
        access_log /bitnami/nginx/logs/oa.access.log;
        error_log  /bitnami/nginx/logs/oa.error.log;

    location / {
             proxy_pass  http://192.168.100.103:8080/;
             proxy_http_version 1.1;
             proxy_set_header Connection "";
             proxy_set_header host $host:$server_port;
             proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
         }
    }

   server {
        listen 80;
        server_name mail.myweb.cn;
        access_log /bitnami/nginx/logs/mail.access.log;
        error_log  /bitnami/nginx/logs/mail.error.log;

    location / {
             proxy_pass  http://192.168.100.103:8081/;
             proxy_http_version 1.1;
             proxy_set_header Connection "";
             proxy_set_header host $host:$server_port;
             proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
             #client_max_body_size    100m;
         }
    }