Docker: Use --mount instead of -v for mounting docker paths

[srirams]

Currently, I believe that unraid is using -v to mount paths in docker. This has the undesirable side effect of creating the path in the host system if it doesn't exist. So, for example, if you've use a bind mount in docker pointing to /mnt/disks/data and /mnt/disks/data does not exist, it will be created in the host system as an empty directory, leading to problems when you want to actually mount something into /mnt/disks/data.

 

Using the --mount syntax instead will not auto create paths. See https://docs.docker.com/storage/bind-mounts/ for reference.

 

Quote

Differences between -v and --mount behavior

Because the -v and --volume flags have been a part of Docker for a long time, their behavior cannot be changed. This means that there is one behavior that is different between -v and --mount.

If you use -v or --volume to bind-mount a file or directory that does not yet exist on the Docker host, -v creates the endpoint for you. It is always created as a directory.

If you use --mount to bind-mount a file or directory that does not yet exist on the Docker host, Docker does not automatically create it for you, but generates an error.

 

[Squid]

Damned if you do, damned if you don't.

 

Many required folders may need to be created depending upon the container - most notably, the appdata folder.

[JonathanM]

Could we get an option in the config like there is for access mode?

[srirams]

21 minutes ago, Squid said:

Damned if you do, damned if you don't.

 

Many required folders may need to be created depending upon the container - most notably, the appdata folder.

 

I think unraid creating the folders when you add a new container is ok, but I don't see the use case for docker ever creating folders when you start a container (its gonna create an empty folder because the appdata folder is not mounted)