[Bug]: buildkit container loose sync when tgz archive

[m-emelchenkov]

I have done the following

• I have searched the existing issues
• If possible, I've reproduced the issue using the 'main' branch of this project

Steps to reproduce

1. container stop buildkit; container rm buildkit.
2. cd Tools; ./run.sh.
3. edit Dockerfile.sh, change "Hello World" to "Hello World 2".
4. ./run.sh.

After the second run, instead of "Hello World 2" output you'll get "Hello World". This is because fssync breaks in buildkit container. It never updates files anymore. I tried different archives but can't reproduce it nowhere except the one attached.

Interestingly, my superpower is finding bugs, and this is literally the first docker image I've ever built on Apple Containers, and it took me a whole day to figure out the cause and create this bug report.

It's fun that I can't upload archive here, "Failed to upload". So here is a link to Google Driver: https://drive.google.com/file/d/1AzUpGAiK2UETB6YaWnt-TbbpN9V3hee9/view?usp=share_link

Current behavior

Does not sync filesystem inside buildkit container.

Expected behavior

Should work flawlessly like Podman and Docker.

Environment

- OS: Tahoe 26.2
- Xcode: N/A
- Container: 0.8.0

Relevant log output

N/A

Code of Conduct

• I agree to follow this project's Code of Conduct

[jglogan]

@m-emelchenkov Can you post the contents of a Dockerfile that reproduces this issue, along with the container commands you used?

[jglogan]

Also could you try posting a zip archive instead of tgz? If we need to repackage it as tgz, we can do that after downloading.

[jglogan]

@m-emelchenkov this made me smile:

Interestingly, my superpower is finding bugs

I've known others with that superpower. It's a very valuable talent!

[m-emelchenkov]

@m-emelchenkov Can you post the contents of a Dockerfile that reproduces this issue, along with the container commands you used?

Please download zip from Google Drive link — it's a self-contained example to reproduce the bug.

[JaewonHur]

Thanks, let me take a look at it.

[JaewonHur]

Hi @m-emelchenkov,
I just made a PR for fixing this issue. Could you give a try?

• Build a custom buildkit image

git clone -b use-tar-hash-as-checksum https://github.com/JaewonHur/container-builder-shim
cd container-builder-shim
container build -t builder -f ./Dockerfile
container kill buildkit
container rm buildit

• Rebuild container

container system stop
git clone -b send-tar-hash https://github.com/JaewonHur/container
cd container
make all install
container system start

• Set custom buildit image as default

container system property set image.builder builder:latest

• Try your testcase
  ...

[m-emelchenkov]

Hi @JaewonHur! Thank you very much for reaching out in a very prompt manner. I have installed the debug branch. It works when editing Dockerfile.sh, though when I add a new file:

cd ./Tools
touch cool.file
[edit Dockerfile and add "COPY cool.file /root" to it right before "WORKDIR" line]
./run.sh

I am getting an error:

#9 [linux/arm64/v8 stage-1 3/5] COPY cool.file /root
#9 ERROR: failed to calculate checksum of ref cunbz8gtsjeof1ekmio2f58i4::wxnhqk9abuz8zsfyruzak9rx3: "/cool.file": not found
------
 > [linux/arm64/v8 stage-1 3/5] COPY cool.file /root:
------
Error: unknown (2): failed to solve: failed to compute cache key: failed to calculate checksum of ref cunbz8gtsjeof1ekmio2f58i4::wxnhqk9abuz8zsfyruzak9rx3: "/cool.file": not found
Warning! Running debug build. Performance may be degraded.

[JaewonHur]

Hi @m-emelchenkov,
Thank you for catching it!

I just updated to hash the metadata also.
Could you please git it another try?

[m-emelchenkov]

Hi @JaewonHur! I have tested it and I like it. I tested:
a) changing Dockerfile.sh;
b) adding file;
c) adding directory with file.
All works OK.

Thanks a lot!!!

By the way, when to expect this fix in stable branch? I mean, the probable version number? Because I mainly use Homebrew so will await it there.