重新创建 docker 绑定安装

Question

如果您绑定挂载一个不存在的文件（在主机上），docker 将愉快地在其位置创建一个目录并与容器共享。在 "fixing" 错误（即停止容器，用文件替换目录并启动容器）时，您将收到以下错误：

docker: Error response from daemon: oci runtime error: container_linux.go:262: starting container process caused "process_linux.go:339: container init caused "rootfs_linux.go:57: mounting "[snip]" to [snip]" at "[snip]" caused "not a directory""" : Are you trying to mount a directory onto a file (or vice-versa)? Check if the specified host path exists and is the expected type.

以下是从控制台重现的一些步骤：

# ensure test file does not exist
$ rm -f /test.txt

# run hello-world container with test.txt bind mount
$ docker run --name testctr -v /test.txt:/test.txt hello-world

Hello from Docker!
This message shows that your installation appears to be working correctly.
<snip>

# let's say what's in /
$ ls -l /

<snip>
dr-xr-xr-x   13 root     root             0 Jul 17 01:08 sys
drwxr-xr-x    2 root     root          4096 Jul 22 20:54 test.txt
drwxrwxrwt    1 root     root          4096 Jul 17 09:01 tmp
<snip>

# let's correct the mistake and run the container again
$ rm -rf /test.txt
$ touch /test.txt
$ docker start testctr

Error response from daemon: OCI runtime create failed: container_linux.go:348: starting
container process caused "process_linux.go:402: container init caused \"rootfs_linux.go:58:
mounting \\"/test.txt\\" to rootfs \\"/var/lib/docker/overlay2/
26fd6981e919e5915c31098fc74551314c4f05ce6c5e175a8be6191e54b7f807/merged\\" at \\"/var/lib/
docker/overlay2/26fd6981e919e5915c31098fc74551314c4f05ce6c5e175a8be6191e54b7f807/merged/
test.txt\\" caused \\"not a directory\\"\"": unknown: Are you trying to mount a directory
onto a file (or vice-versa)? Check if the specified host path exists and is the expected
type
Error: failed to start containers: testctr

请注意，即使我们在启动现有容器时出现此错误，创建一个新容器也确实有效。

所以我的问题是，我该如何解决这个问题？我可以看到两种不同的可能性：

重新创建容器：
- 以某种方式将创建容器 (docker run ...) 的命令导出到变量 (?)
- 删除旧容器
- 运行在步骤 1 中生成的命令
以某种方式调整现有容器以修复安装
- 这可能无法通过 docker 完成，因为绑定安装显然不受 docker

PS: 这个问题也应该解决 this one.

Answer 1

为现有容器生成 docker run ... 的两个选项：

assaflavie/runlike - 我选择了这个，因为另一个标签似乎有一些问题（但这个不支持批量检查）
```
$ docker run --rm -v /var/run/docker.sock:/var/run/docker.sock assaflavie/runlike <container>
```

nexdrew/rekcod

$ docker run --rm -v /var/run/docker.sock:/var/run/docker.sock nexdrew/rekcod <container>

最终脚本看起来像 (未测试):

# get names of running containers (names persist recreation)
running_containers=$(docker ps --format "{{.Names}}")

# stop running containers
docker stop $running_containers

# generate recreate script
containers=$(docker ps --all --format "{{.Names}}")
echo '#!/bin/sh' > ./recreate.sh
while read -r cname; do
  docker run --rm -v /var/run/docker.sock:/var/run/docker.sock assaflavie/runlike "$cname" >> ./recreate.sh
done <<< "$containers"
chmod +x ./recreate.sh

# ... do some action now (maybe also manually check recreate script) ...

# recreate containers
docker rm --force $containers
./recreate.sh

# restart containers that were previously running
docker start $running_containers

这似乎可以解决我的需求，但一些人注意到这些工具可能会遗漏 docker 功能，甚至可能包含错误（例如，我已经在 rekcod 中注意到了这一点），因此请谨慎使用.

重新创建 docker 绑定安装

Recreating docker bind-mount

mount

docker