Alpine installation ignores Python 3.9

[oxeye-ron]

I'm trying to install BCC from the community repositories on Alpine with Python 3.9 installed.
Unfortunately, the installation ignores the existing python and installs Python 3.8 instead.

 ~ docker run -it --entrypoint=/bin/sh python:3.9-alpine                                                                                                                                                                                                                                                  
/ # apk update
fetch https://dl-cdn.alpinelinux.org/alpine/v3.13/main/x86_64/APKINDEX.tar.gz
fetch https://dl-cdn.alpinelinux.org/alpine/v3.13/community/x86_64/APKINDEX.tar.gz
v3.13.5-192-g9af04e1760 [https://dl-cdn.alpinelinux.org/alpine/v3.13/main]
v3.13.5-187-g1477654ee3 [https://dl-cdn.alpinelinux.org/alpine/v3.13/community]
OK: 13891 distinct packages available
/ # ln -s $(which python3) /usr/bin/python
/ # apk add bcc-tools bcc-doc
(1/9) Installing bcc-doc (0.18.0-r0)
(2/9) Installing fts (1.2.7-r1)
(3/9) Installing libelf (0.182-r0)
(4/9) Installing libgcc (10.2.1_pre1-r3)
(5/9) Installing libstdc++ (10.2.1_pre1-r3)
(6/9) Installing bcc (0.18.0-r0)
(7/9) Installing python3 (3.8.10-r0)
(8/9) Installing py3-bcc (0.18.0-r0)
(9/9) Installing bcc-tools (0.18.0-r0)
Executing busybox-1.32.1-r6.trigger
OK: 116 MiB in 45 packages
/ # python3.9
Python 3.9.4 (default, Apr 15 2021, 04:50:04)
[GCC 10.2.1 20201203] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import bcc
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ModuleNotFoundError: No module named 'bcc'
>>> exit()
/ # python3.8
Python 3.8.10 (default, May  6 2021, 00:05:59)
[GCC 10.2.1 20201203] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import bcc
>>> exit()
/ #

[acj]

I think this happens because Python 3.9 in the Docker image is built from source, and Alpine's package manager isn't aware of it.

The base of python:3.9-alpine is Alpine 3.14 now, which has Python 3.9.5 but seems to have a different issue:

/ # /usr/share/bcc/tools/biosnoop
Traceback (most recent call last):
  File "/usr/share/bcc/tools/biosnoop", line 17, in <module>
    from bcc import BPF
  File "/usr/lib/python3.9/site-packages/bcc/__init__.py", line 17, in <module>
    import ctypes as ct
  File "/usr/lib/python3.9/ctypes/__init__.py", line 8, in <module>
    from _ctypes import Union, Structure, Array
ModuleNotFoundError: No module named '_ctypes'

Something related to FFI?

My standard test case is to pull alpine:3.14 (or latest stable version), install bcc-tools, and run one of the top-like tools. I just tried that and was able to run biosnoop, execsnoop, etc.

[muhammaddenis0121-del]

~ docker run -it --entrypoint=/bin/sh python:3.9-alpine
/ # apk update
fetch https://dl-cdn.alpinelinux.org/alpine/v3.13/main/x86_64/APKINDEX.tar.gz
fetch https://dl-cdn.alpinelinux.org/alpine/v3.13/community/x86_64/APKINDEX.tar.gz
v3.13.5-192-g9af04e1760 [https://dl-cdn.alpinelinux.org/alpine/v3.13/main]
v3.13.5-187-g1477654ee3 [https://dl-cdn.alpinelinux.org/alpine/v3.13/community]
OK: 13891 distinct packages available
/ # ln -s $(which python3) /usr/bin/python
/ # apk add bcc-tools bcc-doc
(1/9) Installing bcc-doc (0.18.0-r0)
(2/9) Installing fts (1.2.7-r1)
(3/9) Installing libelf (0.182-r0)
(4/9) Installing libgcc (10.2.1_pre1-r3)
(5/9) Installing libstdc++ (10.2.1_pre1-r3)
(6/9) Installing bcc (0.18.0-r0)
(7/9) Installing python3 (3.8.10-r0)
(8/9) Installing py3-bcc (0.18.0-r0)
(9/9) Installing bcc-tools (0.18.0-r0)
Executing busybox-1.32.1-r6.trigger
OK: 116 MiB in 45 packages
/ # python3.9
Python 3.9.4 (default, Apr 15 2021, 04:50:04)
[GCC 10.2.1 20201203] on linux
Type "help", "copyright", "credits" or "license" for more information.

import bcc
Traceback (most recent call last):
File "", line 1, in
ModuleNotFoundError: No module named 'bcc'
exit()
/ # python3.8
Python 3.8.10 (default, May 6 2021, 00:05:59)
[GCC 10.2.1 20201203] on linux
Type "help", "copyright", "credits" or "license" for more information.
import bcc
exit()
/ #5284