After an experiment with running Podman within an Alpine distrubution in WSL2 was successfully, I wondered could I make a minimal distrubution that had Podman pre-installed ready to go.

This distribution is intended to be an alternative to the Fedora-based WSL (Windows Subsystem for Linux) distribution that Podman Desktop set-up for you.

This only covers the creation of the WSL2 distribution and not the original set-up of setting-up podman.

Starting point

Creating a the root file-system tarball that wsl.exe can use to install the distribution.

This is simply to check the basics work.

Containerfile.alpineroot

FROM public.ecr.aws/docker/library/alpine:3.22.0
ARG MIRROR=https://dl-cdn.alpinelinux.org/alpine/latest-stable/
ADD --chmod=0755 https://gitlab.alpinelinux.org/api/v4/projects/5/packages/generic/v2.14.10/x86_64/apk.static /apk.static
RUN /apk.static --arch x86_64 -X $MIRROR/main -X $MIRROR/community -U --allow-untrusted --root /rootfs --initdb add alpine-base
RUN tar c -z -C /rootfs  --numeric-owner -f /alpine-rootfs.tar.gz .

The original plan was to use public.ecr.aws/docker/library/busybox:unstable-musl as the base container however the busybox container lacks the SSL certs.

Usage

podman build -f Containerfile.alpineroot  --tag alpineroot:rootfs
podman run --rm -it -v .:/host localhost/alpineroot:rootfs cp /alpine-rootfs.tar.gz /host
wsl --install --name "MyAlpine" --from-file .\alpine-rootfs.tar.gz
  1. Build the container image
  2. Run the container image and copy the resulting root file-system tarball out
  3. Install the root file-system as a WSL distribution.

Ideally, this would remove the container image (i.e. rmi)

Result

  • The compressed tarball was 4.4MB.
  • Within WSL2, this resulted in a 11.4 root partition.
  • Alpine functioned as normal.

For comparison you can use the existing root file-system provided.

curl -LO https://dl-cdn.alpinelinux.org/alpine/v3.22/releases/x86_64/alpine-minirootfs-3.22.0-x86_64.tar.gz
wsl --install Alpine322 --fixed-vhd --name "Alpine3.22" --from-file alpine-minirootfs-3.22.0-x86_64.tar.gz

Podman

Containerfile.alpinepod

FROM public.ecr.aws/docker/library/alpine:3.22.0
ARG MIRROR=https://dl-cdn.alpinelinux.org/alpine/latest-stable/
ADD --chmod=0755 https://gitlab.alpinelinux.org/api/v4/projects/5/packages/generic/v2.14.10/x86_64/apk.static /apk.static
RUN /apk.static --arch x86_64 --no-cache -X $MIRROR/main -X $MIRROR/community -U --allow-untrusted --root /rootfs --initdb add alpine-baselayout-data busybox podman ca-certificates iptables
RUN mkdir /rootfs/var/tmp
# Alternative to the above is to install alpine-baselayout (which also installs alpine-baselayout-data)
RUN chroot /rootfs /usr/sbin/update-ca-certificates
RUN tar c -z -C /rootfs  --numeric-owner -f /alpine-pm-rootfs.tar.gz .
  • iptablesis needed for netavark used by podman.
  • ca-certificates and the call to update-ca-certificates is needed for the SSL certificates for podman to be able to fetch from container registries requested via HTTPS.
  • Creation of /var/tmp is to fix the error: 
    Error: internal error: unable to copy from source docker://quay.io/podman/hello:latest: initializing destination containers-storage:[overlay@/var/lib/containers/storage#+/run/containers/storage:overlay.mountopt=nodev]quay.io/podman/hello:latest: creating a temporary directory: stat /var/tmp: no such file or directory
  • --no-cache prevents the APK indices being kept in /var/cache/apk/ in the resulting root file-system.

Usage

podman build -f Containerfile.alpinepod  --tag alpinepod:rootfs
podman run --rm -it -v .:/host localhost/alpinepod:rootfs cp /alpine-pm-rootfs.tar.gz /host
wsl --install --name "MyAlpine" --from-file .\alpine-rootfs.tar.gz
  1. Build the container image
  2. Run the container image and copy the resulting root file-system tarball out
  3. Install the root file-system as a WSL distribution.

Ideally, this would remove the container image (i.e. rmi)

Problems

WSL Init

This problem was not critical as the distribution still booted and you can then run podman, however it was bugging me.

<3>WSL (12 - Relay) ERROR: CreateProcessParseCommon:1008: getpwuid(0) failed 2
wsl: Processing /etc/fstab with mount -a failed.
<3>WSL (12 - Relay) ERROR: operator():519: getpwuid(0) failed

This was fixed by installing alpine-baselayout-data. Not sure if this is the /etc/fstab or also needs /etc/shadow, /etc/passwd for user (see below).

Unknown uid

For example running whoami reports unknown uid.

~ # whoami
whoami: unknown uid 0

This is fixed by alpine-baselayout-data so best to simply install that. It is less than 20KiB.

Result

The following output (and input echo) includes output from the WSL set-up command which by default installs and then runs it.

Installing: .\alpine-pm-rootfs.tar.gz
Distribution successfully installed. It can be launched via 'wsl.exe -d AlpineTest'
Launching AlpineTest...

~ # podman run --rm -it quay.io/podman/hello
Trying to pull quay.io/podman/hello:latest...
Getting image source signatures
Copying blob 81df7ff16254 done   |
Copying config 5dd467fce5 done   |
Writing manifest to image destination
!... Hello Podman World ...!

[rest of output excluded]
  • The compressed tarball was 35MB
  • The uncompresed tarball was 95MB
  • Within WSL2, this resulted in a 93MB root partition.
  • Alpine functioned as normal.

Future Work

  • Possibly set-up it up to use rootless
  • Set-up ssh server and socket to allow podman running as a native Windows process to connect and use it.

Tid-bits

  • Tried using busybox:unstable-musl as the base image but it lacks the SSL certificates for apk.static to be able to resolve the package registry.
  • To install extra packages after installing the disturubtion, the apk.static can be downloaded and then extra packages added i.e. 
    wget https://gitlab.alpinelinux.org/api/v4/projects/5/packages/generic/v2.14.10/x86_64/apk.static
chmod +x ~/apk.static
./apk.static  --allow-untrusted -X https://dl-cdn.alpinelinux.org/alpine/latest-stable/main add nano

Wolfi - Root File-system (Update 2025-06-26)

This creates a WSL2 distribution using Wolfi from Chainguard.

This one I simply set-up as a single command call to keep it all self-contained. Otherwise, I would have considered having a “build.sh” and putting that in current folder and utilise the mount to have that file in the container and run it.

podman run --rm -v .:/host --entrypoint /bin/sh docker.io/chainguard/wolfi-base -c "/usr/bin/apk --arch x86_64 -X https://apk.cgr.dev/chainguard/ -U --allow-untrusted --root /rootfs --initdb add wolfi-base chainguard-keys mount umount && touch /rootfs/etc/fstab && tar c -z -C /rootfs  --numeric-owner -f /host/wolfi.tar.gz ."
wsl --install --name "MyWolfi" --from-file .\wolfi.tar.gz

The first issue issue was:

wsl: Processing /etc/fstab with mount -a failed.
wsl: Failed to mount C:\, see dmesg for more details.
...
wsl: Failed to translate '<item in %PATH% from Windows>'
... Same as above repeated for each directory in %PATH%.

Running dmesg it shows:

[ 7536.455675] WSL (2 - init(MyWolfi)) ERROR: UtilCreateProcessAndWait:685: /bin/mount failed with 2
[ 7536.456840] WSL (1 - init(MyWolfi)) ERROR: UtilCreateProcessAndWait:707: /bin/mount failed with status 0xff00

The problem here is /bin/mount doesn’t exist. In Alpine, /bin/mount is linked to /bin/bbsuid. The solution was add mount in addition to wolfi-base. While its not required for starting the distribution, it seemed like a good idea to also include umount to be able to unmount a file-system.

The issue is apk’s repositories file is missing, so you can’t add any extra packages (you could manually add the /etc/apk/repositories with the contents).. Initially there was the issue where the signature for it were missing too (so the --allow-untrusted argument needs to be used). That problem was addressed by adding the chainguard-keys package.

An alternative to using the Chainguard distribution would be use https://packages.wolfi.dev/os/<arch>, which if this was used the wolfi-keys package needs to be installed.

Expectation

I am planning on updating this post if I complete the future work, rather than doing a part 2.