Is there any way to mount a named volume as a non-root user? I am trying to avoid having to run a chown in each Dockerfile but I need the mount to be writable by a non-root user to be able to write the artifacts created by a build in the image
This is what I'm trying
docker run --rm -it -v /home/bob/dev/:/src/dev -v builds:/mnt/build --name build hilikus/build /bin/bash
but for the second mount I get
[user@42f237282128 ~]$ ll /mnt
total 4
drwxr-xr-x 2 root root 4096 Sep 18 19:29 build
My other mount (/src/dev/) is owned by user, not by root so it gives what I need; however, I haven't been able to do the same with the named volume.
The named volume initializes to the contents of your image at that location, so you need to set the permissions inside your Dockerfile:
$ cat df.vf-uid
FROM busybox
RUN mkdir -p /data && echo "hello world" > /data/hello && chown -R 1000 /data
$ docker build -t test-vf -f df.vf-uid .
Sending build context to Docker daemon 23.06 MB
Step 1 : FROM busybox
---> 2b8fd9751c4c
Step 2 : RUN mkdir -p /data && echo "hello world" > /data/hello && chown -R 1000 /data
---> Using cache
---> 41390b132940
Successfully built 41390b132940
$ docker run -v test-vol:/data --rm -it test-vf ls -alR /data
/data:
total 12
drwxr-xr-x 2 1000 root 4096 Sep 19 15:26 .
drwxr-xr-x 19 root root 4096 Sep 19 15:26 ..
-rw-r--r-- 1 1000 root 12 Aug 22 11:43 hello
If you use the new --mount syntax instead of the old -v/--volume syntax it is supposedly possible to assign a uid to the volume's contents via docker volume create somename --opt -o=uid=1000 or something similar.
See https://docs.docker.com/engine/reference/commandline/volume_create/#driver-specific-options
I haven't fully tested this to run as non-root or using the dockremap dynamic user with the userns-map option but hope to soon.
来源：https://stackoverflow.com/questions/39564861/mount-named-volume-as-non-root-in-docker