Docker卷内容不持久 [英] Docker volume content does not persist

问题描述

我正在尝试以某种方式捕获docker容器的状态，包括包含已添加到该容器内卷中的文件的图像。因此，如果我以这种方式运行原始容器：

I am trying to capture the state of a docker container as an image, in a way that includes files I have added to a volume within the container. So, if I run the original container in this way:

$ docker run -ti -v /cookbook ubuntu:14.04 /bin/bash
root@b78f3599d936:/# cd cookbook
root@b78f3599d936:/cookbook# touch foo.txt

现在，如果我将容器导出或提交为新的Docker映像，然后从新映像运行容器，则foo.txt文件将永远不会包含在/ cookbook目录中。

Now, if I either export, or commit the container as a new docker image, and then run a container from the new image, then the file, foo.txt is never included in the /cookbook directory.

我的问题是是否有一种方法可以从容器中创建图像，从而允许图像在其卷中包括文件内容。

My question is whether there is a way to create an image from a container in a way that allows the image to include file content within its volumes.

推荐答案

通过将更改放入卷中，您可以将它们从实际容器中排除。 docker export 的文档包括：

Well, by putting the changes in a volume, you're excluding them from the actual container. The documentation for docker export includes this:

docker export命令不会导出与容器关联的卷的内容。如果将卷安装在容器中现有目录的顶部，则docker export将导出基础目录的内容，而不是卷的内容。

The docker export command does not export the contents of volumes associated with the container. If a volume is mounted on top of an existing directory in the container, docker export will export the contents of the underlying directory, not the contents of the volume.

请参阅备份，还原，或迁移用户指南中的数据卷，例如有关导出卷中数据的示例。

Refer to Backup, restore, or migrate data volumes in the user guide for examples on exporting data in a volume.

这指向此文档。请按照那里的步骤导出存储在卷中的信息。

This points to this documentation. Please follow the steps there to export the information stored in the volume.

您可能正在寻找类似的东西：

You're probably looking for something like this:

docker run --rm --volumes-from <containerId> -v $(pwd):/backup ubuntu tar cvf /backup/backup.tar /cookbook

这将创建一个文件 backup.tar 和容器的 / cookbook 目录的内容，并将其存储在主机的当前目录中。然后，您可以使用此tar文件将其导入另一个容器中。

This would create a file backup.tar with the contents of the container's /cookbook directory and store it in the current directory of the host. You could then use this tar file to import it in another container.

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