[Request]: Create volumes automatically

[jibes-cried]

Feature or enhancement request details

When i spin up a new container, and i have a line like this
-v tailscale-ai-state:/var/lib/tailscale \
and volume is not created, it fails.

On docker, if volume does not exist, it is created automatically, which is very handy.

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[peterpeterparker]

I also started integrating support for Apple’s container in my tooling (juno-docker) yesterday and ran into the same issue.

At first I tried to work around it by explicitly creating the volume with container volume create and then passing it to container run, but that led to the mount point being an empty root:root dir. In Docker/Podman the directory inside the image gets copied into the volume with its ownership, so my non-root user can write there. With container it’s always root-owned and my app fails with Permission denied.

So it’s not only about auto-creating volumes, but also about mimicking Docker/Podman “copy-up” behavior so that permissions/ownership are preserved on first use.

[dcantah]

@peterpeterparker Could you describe the scenario that functions for docker/podman but doesn't here with a repro? Afair (and from trialing super quick) anonymous volumes for docker, even if I ask to be some uid:gid pair/username, still end up as root in the container.

[peterpeterparker]

@dcantah sure. Here's the minimal reproducible snippet I used to compare the difference.

Dockerfile:

FROM debian:stable-slim

RUN useradd -ms /bin/bash apprunner
USER apprunner

WORKDIR /test

RUN mkdir -p /test/demo
VOLUME ["/test"]

CMD ["/bin/bash"]

Docker command succeed ✅:

docker build -t volume-test .      
docker run --rm -v vol-test123:/test volume-test touch /test/demo/hello
docker run --rm -v vol-test123:/test volume-test ls -l /test/demo   
total 0
-rw-r--r-- 1 apprunner apprunner 0 Sep 30 05:13 hello

Apple container issue when create folder ❌:

container build -t volume-test .
container volume create vol-test
container run --rm -v vol-test:/test volume-test sh -lc 'mkdir -p /test/demo && touch /test/demo/hello'
mkdir: cannot create directory '/test/demo': Permission denied

[ldemailly]

Hesitated to file a new issue but I have the inverse problem - which is that if the volume isn't mapped it should imo like docker just write to a new layer

I have a

VOLUME ["/home/user/.tsync"]

and I get a
21:45:29.842 r1 [FTL] Failed to load or create identity: mkdir /home/user/.tsync: no such file or directory

if I don't -v it

[mungler]

I have the same issue with a named volume trying to store data for a MySQL server container. With an empty 'mysql-data' volume already created, I get:

rory@Zaphod ~> /usr/local/bin/container run --rm --publish 3336:3306 -v mysql-data:/var/lib/mysql:rw -e MYSQL_DATABASE=<redacted> -e MYSQL_USER=<redacted> -e MYSQL_PASSWORD=<redacted> docker.io/percona/percona-server:8.0.34-26.1-multi --character-set-server=utf8mb4 --collation-server=utf8mb4_unicode_ci --log_bin_trust_function_creators=1
Initializing database            
mysqld: Can't create/write to file '/var/lib/mysql/is_writable' (OS errno 13 - Permission denied)

PS @peterpeterparker are you really @peterpeterparker or are you really @spiderspiderman? 😆 (sorry)

[mungler]

In fact, I opened a new issue, since this isn't the same problem: #745