实验环境：

三台阿里云服务器 

master：59.110.224.16  iZ2zebnlswk1d44x5zohfoZ

worker1：47.94.164.5  iZ2ze5ys0umutubelpncwsZ

worker2：47.104.105.70  iZm5e8mciwctrh1zj1f7r3Z

操作系统 centos ，3306端口已开，8089端口已开

步骤：

1.docker network create -d overlay demo

2.docker service create --name mysql --env MYSQL_ROOT_PASSWORD=root --env MYSQL_DATABASE=wordpress --network demo --mount type=volume,source=mysql-data,destination=/var/lib/mysql -p 3306:3306 mysql:5.7

mysql 服务此时被安装在47.104.105.70上

3.docker service create --name wordpress -p 8089:80 --env WORDPRESS_DB_PASSWORD=root --env WORDPRESS_DB_HOST=47.104.105.70:3306 --network demo wordpress

现象：

1.在创建mysql service时，我必须要-p 3306:3306 才能让wordpress服务访问到

2.在创建wordpress service时，我必须要写明WORDPRESS_DB_HOST=47.104.105.70:3306，也就是指定mysql所在的IP以及端口号3306

只有这样写我才能打开wordpress，但是虽然可以打开但是其他节点缺无法访问到

docker service ls 结果如下：

yqtfn4z75ai3        mysql               replicated          1/1                 mysql:5.7           *:3306->3306/tcp

ymkaere3fnml        wordpress           replicated          1/1                 wordpress:latest    *:8089->80/tcp

master->docker network ls ->存在demo的overlay

worker1->docker network ls ->不存在demo的overlay

worker2->docker network ls ->存在demo的overlay

[root@iZ2zebnlswk1d44x5zohfoZ ~]# docker service logs wordpress

wordpress.1.quo67ighyp3n@iZ2zebnlswk1d44x5zohfoZ    | WordPress not found in /var/www/html - copying now...

wordpress.1.quo67ighyp3n@iZ2zebnlswk1d44x5zohfoZ    | Complete! WordPress has been successfully copied to /var/www/html

wordpress.1.quo67ighyp3n@iZ2zebnlswk1d44x5zohfoZ    | AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 10.0.0.13. Set the 'ServerName' directive globally to suppress this message

wordpress.1.quo67ighyp3n@iZ2zebnlswk1d44x5zohfoZ    | AH00558: apache2: Could not reliably determine the server's fully qualified domain name, using 10.0.0.13. Set the 'ServerName' directive globally to suppress this message

wordpress.1.quo67ighyp3n@iZ2zebnlswk1d44x5zohfoZ    | [Mon May 07 10:17:31.562835 2018] [mpm_prefork:notice] [pid 1] AH00163: Apache/2.4.25 (Debian) PHP/7.2.5 configured -- resuming normal operations

wordpress.1.quo67ighyp3n@iZ2zebnlswk1d44x5zohfoZ    | [Mon May 07 10:17:31.562890 2018] [core:notice] [pid 1] AH00094: Command line: 'apache2 -D FOREGROUND'

wordpress.1.quo67ighyp3n@iZ2zebnlswk1d44x5zohfoZ    | 10.255.0.2 - - [07/May/2018:10:17:45 +0000] "GET / HTTP/1.1" 200 18718 "-" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36"

wordpress.1.quo67ighyp3n@iZ2zebnlswk1d44x5zohfoZ    | 10.255.0.2 - - [07/May/2018:10:17:46 +0000] "GET /favicon.ico HTTP/1.1" 200 227 "http://59.110.224.16:8089/" "Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/65.0.3325.181 Safari/537.36"

访问：59.110.224.16:8089

访问其他IP都不行