Question

我正在使用docker-compose（以前的无花果）在docker中运行一个简单的rails应用程序：

搬运工-compose.yml

db:
  image: postgres
  volumes:
    - pgdata:/var/lib/postgresql/data

web:
  build: .
  command: bundle exec rails s -b 0.0.0.0
  volumes:
    - .:/usr/src/app
  ports:
    - "3011:3000"
  links:
    - db

Dockerfile

FROM rails:onbuild

我需要运行一些定期维护脚本，例如数据库备份，将站点地图ping到搜索引擎等。

我不想在我的主机上使用cron，因为我更喜欢保持应用程序的可移植性，我的想法是使用docker-compose使用docker-compose链接https://registry.hub.docker.com/u/hamiltont/docker-cron/等图像。 / p>

rails官方映像没有启用ssh所以我不能只让cron容器进入Web容器并运行脚本。

docker-compose是否有办法让容器获取shell进入链接容器以执行某些命令？

Answer 1

What actually would you like to do with your containers? If you need to access some objects from container's file system, you should just mount the volume to the ancillary container (consider --volumes-from option).

Any SSH interaction between containers is considered as a bad practice (at least since docker 1.3, when docker exec has been implemented). Running more than one process inside the container (e.g. smth but the postgres or rails in your case) will result in a large overhead: in order to have a sshd along with rails you'll have to deploy something like supervisord.

But if you really need to provide some kind of nonstandard interaction between the containers and you're sure that you really need it, I would suggest you to use one of the full-featured docker client libraries (like docker-py). It will allow you to launch docker exec in a programmable way.

使用docker-compose（以前称为fig）链接cron图像

1 个答案: