Swarm mode 集群服务编排的高可用性调度

模板版本支持

• 
  availability:az==3
  服务至少分布在 3 个可用区中；如果当前集群没有 3 个可用区，或机器资源不够导致无法分布在 3 个可用区，容器创建会失败。
• 
  availability:az==~3
  服务尽可能分布在 3 个可用区中；无法满足时依然可以成功创建。

1. [backcolor=transparent]nnn[backcolor=transparent]:
2. [backcolor=transparent]  expose[backcolor=transparent]:
3. [backcolor=transparent]    [backcolor=transparent]-[backcolor=transparent] [backcolor=transparent]443[backcolor=transparent]/[backcolor=transparent]tcp
4. [backcolor=transparent]    [backcolor=transparent]-[backcolor=transparent] [backcolor=transparent]80[backcolor=transparent]/[backcolor=transparent]tcp
5. [backcolor=transparent]  image[backcolor=transparent]:[backcolor=transparent] [backcolor=transparent]'nginx:latest'
6. [backcolor=transparent]  environment[backcolor=transparent]:
7. [backcolor=transparent]    [backcolor=transparent]-[backcolor=transparent] [backcolor=transparent]'availability:az==2'
8. [backcolor=transparent]  labels[backcolor=transparent]:
9. [backcolor=transparent]    aliyun[backcolor=transparent].[backcolor=transparent]scale[backcolor=transparent]:[backcolor=transparent] [backcolor=transparent]'8'
10. [backcolor=transparent]  restart[backcolor=transparent]:[backcolor=transparent] always
11. [backcolor=transparent]  volumes[backcolor=transparent]:
12. [backcolor=transparent]    [backcolor=transparent]-[backcolor=transparent] [backcolor=transparent]/var/[backcolor=transparent]cache[backcolor=transparent]/[backcolor=transparent]nginx