Unable to install opencv-python at ubuntu 18.04 using dockerfile

[ztjse145]

Collecting opencv-python (from -r requirements.txt (line 4))
#8 25.19 Downloading https://files.pythonhosted.org/packages/33/92/87e99adfaf9c847021ecfcd4bf2732c863752cf47c0c9ad349c8de260183/opencv-python-4.7.0.68.tar.gz
(91.1MB)
Complete output from command python setup.py egg_info:
Traceback (most recent call last):
File "", line 1, in
File "/tmp/pip-build-4qltk6ih/opencv-python/setup.py", line 10, in
import skbuild
ModuleNotFoundError: No module named 'skbuild'

Command "python setup.py egg_info" failed with error code 1 in /tmp/pip-build-4qltk6ih/opencv-python/