Технічне: використання python:3.12-slim базового імеджа для svg_gererator

[yurnov]

При тесуванні PR #187 було виявленно, що svg_generator.py падає при використанні базового імеджа python:3.12-slim (чи іншого slim-образа). Для того, щоб вмерджити PR @v00g100skr замінив імедж на python:3.12-bullseye, а цей PR фактично є фіксом, що виправляє роботу svg_generator.py з slim імеджем.

Причиною є відпустність бібліотеки libcairo2, що потрібна для пакету cairosvg:

docker run -it --rm python:3.12-slim bash
root@e60baa3d93aa:/# pip install cairosvg==2.7.1
Collecting cairosvg==2.7.1
  Downloading CairoSVG-2.7.1-py3-none-any.whl.metadata (2.7 kB)
Collecting cairocffi (from cairosvg==2.7.1)
  Downloading cairocffi-1.6.1-py3-none-any.whl.metadata (3.3 kB)
Collecting cssselect2 (from cairosvg==2.7.1)
  Downloading cssselect2-0.7.0-py3-none-any.whl.metadata (2.9 kB)
Collecting defusedxml (from cairosvg==2.7.1)
  Downloading defusedxml-0.7.1-py2.py3-none-any.whl.metadata (32 kB)
Collecting pillow (from cairosvg==2.7.1)
  Downloading pillow-10.3.0-cp312-cp312-manylinux_2_28_x86_64.whl.metadata (9.2 kB)
Collecting tinycss2 (from cairosvg==2.7.1)
  Downloading tinycss2-1.2.1-py3-none-any.whl.metadata (3.0 kB)
Collecting cffi>=1.1.0 (from cairocffi->cairosvg==2.7.1)
  Downloading cffi-1.16.0-cp312-cp312-manylinux_2_17_x86_64.manylinux2014_x86_64.whl.metadata (1.5 kB)
Collecting webencodings (from cssselect2->cairosvg==2.7.1)
  Downloading webencodings-0.5.1-py2.py3-none-any.whl.metadata (2.1 kB)
Collecting pycparser (from cffi>=1.1.0->cairocffi->cairosvg==2.7.1)
  Downloading pycparser-2.22-py3-none-any.whl.metadata (943 bytes)
Downloading CairoSVG-2.7.1-py3-none-any.whl (43 kB)
   ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 43.2/43.2 kB 1.1 MB/s eta 0:00:00
Downloading cairocffi-1.6.1-py3-none-any.whl (75 kB)
   ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 75.1/75.1 kB 2.2 MB/s eta 0:00:00
Downloading cssselect2-0.7.0-py3-none-any.whl (15 kB)
Downloading defusedxml-0.7.1-py2.py3-none-any.whl (25 kB)
Downloading pillow-10.3.0-cp312-cp312-manylinux_2_28_x86_64.whl (4.5 MB)
   ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 4.5/4.5 MB 45.5 MB/s eta 0:00:00
Downloading tinycss2-1.2.1-py3-none-any.whl (21 kB)
Downloading cffi-1.16.0-cp312-cp312-manylinux_2_17_x86_64.manylinux2014_x86_64.whl (477 kB)
   ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 477.6/477.6 kB 12.3 MB/s eta 0:00:00
Downloading webencodings-0.5.1-py2.py3-none-any.whl (11 kB)
Downloading pycparser-2.22-py3-none-any.whl (117 kB)
   ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ 117.6/117.6 kB 3.3 MB/s eta 0:00:00
Installing collected packages: webencodings, tinycss2, pycparser, pillow, defusedxml, cssselect2, cffi, cairocffi, cairosvg
Successfully installed cairocffi-1.6.1 cairosvg-2.7.1 cffi-1.16.0 cssselect2-0.7.0 defusedxml-0.7.1 pillow-10.3.0 pycparser-2.22 tinycss2-1.2.1 webencodings-0.5.1
WARNING: Running pip as the 'root' user can result in broken permissions and conflicting behaviour with the system package manager. It is recommended to use a virtual environment instead: https://pip.pypa.io/warnings/venv
root@e60baa3d93aa:/# python -c "import cairosvg"
Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/usr/local/lib/python3.12/site-packages/cairosvg/__init__.py", line 26, in <module>
    from . import surface  # noqa isort:skip
    ^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/cairosvg/surface.py", line 9, in <module>
    import cairocffi as cairo
  File "/usr/local/lib/python3.12/site-packages/cairocffi/__init__.py", line 47, in <module>
    cairo = dlopen(
            ^^^^^^^
  File "/usr/local/lib/python3.12/site-packages/cairocffi/__init__.py", line 44, in dlopen
    raise OSError(error_message)  # pragma: no cover
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
OSError: no library called "cairo-2" was found
no library called "cairo" was found
no library called "libcairo-2" was found
cannot load library 'libcairo.so.2': libcairo.so.2: cannot open shared object file: No such file or directory.  Additionally, ctypes.util.find_library() did not manage to locate a library called 'libcairo.so.2'
cannot load library 'libcairo.2.dylib': libcairo.2.dylib: cannot open shared object file: No such file or directory.  Additionally, ctypes.util.find_library() did not manage to locate a library called 'libcairo.2.dylib'
cannot load library 'libcairo-2.dll': libcairo-2.dll: cannot open shared object file: No such file or directory.  Additionally, ctypes.util.find_library() did not manage to locate a library called 'libcairo-2.dll'
root@e60baa3d93aa:/# 

Рішенням є поставити пакет libcairo2

Тесувалось на тестовому SVG за допомогою консольної cairosvg

Результат +13MB за рахунок libcairo.2 та залежностей, але все одно, імедж майже впятеро менший:

$ docker images
REPOSITORY                  TAG             IMAGE ID       CREATED             SIZE
svg                         3.12-slim       0c3f213ffb54   9 seconds ago       174MB
svg                         3.12-bullseye   45ff6c29e26c   53 minutes ago      963MB