[Seahub 12.0.7] Error when generating thumbnail pdf

[amof]

Hello,

I'm using Seafile version 12.0.7 in a Docker environment.
While having an issue with Seafile (which was a configuration issue on my side), I came across this error in seahub.log:

[2025-01-21 13:58:46] [ERROR] seahub.thumbnail.utils:211 pdf_bytes_to_images [Errno 2] No such file or directory: 'pdftoppm'
[2025-01-21 13:58:46] [ERROR] seahub.thumbnail.utils:239 create_pdf_thumbnails [Errno 2] No such file or directory: '/tmp/c3aecf34.png'
[2025-01-21 13:58:46] [ERROR] django.request:241 log_response Internal Server Error: /thumbnail/d49e13b5-d1d8-498a-86bb-939f9a3674bb/create/
Traceback (most recent call last):
  File "/opt/seafile/seafile-server-12.0.7/seahub/seahub/thumbnail/utils.py", line 235, in create_pdf_thumbnails
    ret = _create_thumbnail_common(tmp_path, thumbnail_file, size)
          ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/seafile/seafile-server-12.0.7/seahub/seahub/thumbnail/utils.py", line 278, in _create_thumbnail_common
    image = Image.open(fp)
            ^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/dist-packages/PIL/Image.py", line 3431, in open
    fp = builtins.open(filename, "rb")
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
FileNotFoundError: [Errno 2] No such file or directory: '/tmp/c3aecf34.png'

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/opt/seafile/seafile-server-12.0.7/seahub/thirdpart/django/core/handlers/exception.py", line 55, in inner
    response = get_response(request)
               ^^^^^^^^^^^^^^^^^^^^^
  File "/opt/seafile/seafile-server-12.0.7/seahub/thirdpart/django/core/handlers/base.py", line 197, in _get_response
    response = wrapped_callback(request, *callback_args, **callback_kwargs)
               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/seafile/seafile-server-12.0.7/seahub/seahub/auth/decorators.py", line 69, in _wrapped_view
    return view_func(request, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/seafile/seafile-server-12.0.7/seahub/seahub/thumbnail/views.py", line 59, in thumbnail_create
    success, status_code = generate_thumbnail(request, repo_id, size, path)
                           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/seafile/seafile-server-12.0.7/seahub/seahub/thumbnail/utils.py", line 129, in generate_thumbnail
    return create_pdf_thumbnails(repo, file_id, path, size,
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/seafile/seafile-server-12.0.7/seahub/seahub/thumbnail/utils.py", line 240, in create_pdf_thumbnails
    os.unlink(tmp_path)
FileNotFoundError: [Errno 2] No such file or directory: '/tmp/c3aecf34.png'

Upon inspection in source code in seahub/seahub/thumbnail/utils.py, I saw that this was where the error is coming from:

def pdf_bytes_to_images(pdf_bytes, prefix_path, dpi=200):
    with tempfile.NamedTemporaryFile(delete=True, suffix='.pdf') as tmpfile:
        tmpfile.write(pdf_bytes)
        tmp_file = tmpfile.name
        command = [
            'pdftoppm',
            '-png',
            '-r', str(dpi),
            '-f', '1',
            '-l', '1',
            '-singlefile', tmp_file,
            '-o', prefix_path
        ]
        try:
            subprocess.check_output(command)
        except Exception as e:
            logger.error(e)
            return (False, 500)

The tool used is pdftoppm. I connected to the seafile container and I noticed that this utility was not installed:

root@:/opt/seafile# pdftoppm
bash: pdftoppm: command not found

So, I installed it (by adding poppler-utils) and now everything is working.

In conclusion, it seems that the Docker image is missing this poppler-utils in order to generate the pdf thumbnails correctly.
That's why I raised the issue here rather than in the Seahub repository.

[SkywalkerSpace]

Thank you for your feedback, we will fix this issue in the next version.