Building container images with python 2.7 in kolla failed due to get_pip macro

[Alexey Kashavkin]

When I try to build image with Python 2.7 I got error:

RUN curl https://bootstrap.pypa.io/get-pip.py -o get-pip.py && python get-pip.py && rm get-pip.py
 ---> Running in 9fc6f53e4185
curl (https://bootstrap.pypa.io/get-pip.py): response: 200, time: 0.374, size: 1928477
Traceback (most recent call last):
  File "get-pip.py", line 24226, in <module>

    main()
  File "get-pip.py", line 199, in main
    bootstrap(tmpdir=tmpdir)
  File "get-pip.py", line 82, in bootstrap

    from pip._internal.cli.main import main as pip_entry_point
  File "/tmp/tmp4rplra/pip.zip/pip/_internal/cli/main.py", line 60
    sys.stderr.write(f"ERROR: {exc}")

                  ^

SyntaxError:
invalid syntax

On January 23rd, the get_pip.py script was modified and now doesn't work well with Python 2.7. I used https://bootstrap.pypa.io/2.7/get-pip.py as a solution, but I think it needs to be correctly added to macros.

[Radosław Piliszek (yoctozepto)]

Yes, we already have a fix in place: https://review.opendev.org/c/openstack/kolla/+/758057