在Docker容器之间共享卷 [英] Sharing volume between Docker containers
问题描述
我正在使用Docker部署一些服务，并且我想在不同容器之间共享Docker卷。
I am using Docker to deploy some services and I want to share the Docker volumes between different containers.
假设我有一个Docker容器A，它在/ data上安装了一个卷。这是它的Dockerfile：
Suppose I have a Docker container A which mounts a volume at /data. Here is its Dockerfile:
VOLUME /data
据我了解，这会将一个卷附加到容器，但不会将主机目录挂载到该容器。因此，该卷中的数据仍位于容器A中。
From my understanding, this will attach a volume to the container but it will not mount a host directory to the container. So the data inside this volume is still inside the container A.
我有另一个提供FTP服务的容器B。它访问卷/ public下的数据。它的Dockerfile是：
I have another container B which provides an FTP service. It accesses the data under volume /public. Its Dockerfile is:
VOLUME /public
<现在，我想将它们链接在一起，以便可以使用B来管理A的数据。来自Docker文档 https://docs.docker.com/engine/userguide/containers / dockervolumes / 我将使用-volumes-from 标志将A的数据量装载到B。但是此命令会将A的数据装载到<$ c $ B中的c> / data 而不是 / public ，在这种情况下，容器B无法访问数据。我没有找到重命名安装点的任何方法。
Now I want to link them together so that I can use B to manage A's data. From the Docker doc https://docs.docker.com/engine/userguide/containers/dockervolumes/ I shall use the --volumes-from flag to mount A's data volume to B. But this command will mount A's data to /data in B instead of /public, and in this case, the container B is not able to access the data. I didn't see any way to rename the mount point.
有任何建议或最佳实践来处理这种情况吗？
Any suggestions or best practices to handle this case?
仅数据容器为这种情况提供了很好的解决方案。但是，如果您要使用volume-from并将数据装入到不同的装入点，则此问题可能会有所帮助！
如何使用Docker的--volumes映射卷路径-from？
The data-only container gives a good solution for this case. But if you want to use volumes-from and mount the data to different mount point, this question may be helpful! How to map volume paths using Docker's --volumes-from?
推荐答案
您可能会发现很多指向纯数据容器和
You may find a lot of pointers mentioning data-only containers and --volumes-from. However, since docker 1.9, volumes have become first class citizens, they can have names, and have more flexibility:
现在很容易实现所需的行为，这是示例：
It's now easy to achieve the behavior you want, here's an example :
-
创建名称为
service-data的命名数据卷：
docker volume create --name service-data
然后您可以使用 -v 标志创建一个将其装入/ public文件夹的容器：
You can then create a container that mounts it in your /public folder by using the -v flag:
docker run -t -i -v service-data:/public debian:jessie /bin/bash
出于测试目的，我们在映射的文件夹中创建一个小的文本文件：
For testing purpose we create a small text file in our mapped folder:
cd public
echo 'hello' > 'hello.txt'
然后可以将命名卷附加到第二个容器，但是这次在数据文件夹下：
You may then attach your named volume to a second container, but this time under the data folder:
docker run -t -i -v service-data:/data debian:jessie /bin/bash
ls /data #-->shows "hello.txt"
请记住，如果两个容器都使用不同的图像，请注意所有权和权限！
Just remember, if both containers are using different images, be careful with ownership and permissions!
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