tar: invalid tar magic

[seunggookim]

Hi, I'm trying to create a Singularity image from a Docker image, which was successfully pulled and runs fine. But I get an invalid tar magic error when running:

$ sudo docker run -v /var/run/docker.sock:/var/run/docker.sock -v ~/Downloads:/output --privileged -t --rm quay.io/singularity/docker2singularity --name jukemir jukemir/representations_jukebox

Image Format: squashfs
Docker Image: jukemir/representations_jukebox
Container Name: jukemir

Inspected Size: 15941 MB

(1/10) Creating a build sandbox...
(2/10) Exporting filesystem...
tar: invalid tar magic

So, I opened an interactive shell (-it --entrypoint /bin/bash), installed BSDtar (apk add libarchive-tools), created a symbolic link to /usr/bin/bsdtar from /bin/tar, then it works now:

bash-5.0# ./docker2singularity.sh jukemir/representations_jukebox

Image Format: squashfs
Docker Image: jukemir/representations_jukebox

Inspected Size: 15941 MB

(1/10) Creating a build sandbox...
(2/10) Exporting filesystem...
(3/10) Creating labels...
(4/10) Adding run script...
(5/10) Setting ENV variables...
(6/10) Adding mount points...
(7/10) Fixing permissions...
(8/10) Stopping and removing the container...
(9/10) Building squashfs container...
INFO:    Starting build...

But could there be a workaround still using the BusyBox tar? Thanks!

[vsoch]

Oh that's strange! It sounds like the fix you have in mind would work for the base image - would you care to PR to add it?

Also, this tool is a bit old (created before Singularity could pull from docker) in case it's easier you can just do:

$ singularity pull docker://<container>

[seunggookim]

Thank you for letting me know that! Actually I couldn’t pull a Docker image from Singularity on our HPC server, so I tried Docker2Singularity on my local machine, where I haven’t build a latest version of Singularity (neuro-debian’s singularity-container could not recognized FIS files). Perhaps building a new version of Singularity on my local machine might have been easier... I can add a few lines in the shell script to make changes as I did to make a PR later. Thanks! Seung-Goo

…

On 8. Jun 2022, at 13:57, Vanessasaurus ***@***.***> wrote: Oh that's strange! It sounds like the fix you have in mind would work for the base image - would you care to PR to add it? Also, this tool is a bit old (created before Singularity could pull from docker) in case it's easier you can just do: $ singularity pull docker://<container> — Reply to this email directly, view it on GitHub <#120 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/APUZ6NCLOBEGSWMZC7H5ATTVOCDCHANCNFSM5YFZU4NA>. You are receiving this because you authored the thread.

[seunggookim]

I've installed the prebuilt Singularity (3.10.0) on my local Linux and pull the Docker image with sudo, and the SIF file was successfully created. So, this works well for me! I'm closing the issue. Thanks.