Upgrade pip in all Docker images.

[bcipriano]

Link the Issue(s) this Pull Request is related to.
Fixes #745

Summarize your change.
The base CentOS image uses an old version of pip, which can cause errors when trying to upgrade setuptools. Upgrade pip in all Docker images to fix this.

This exposes an issue with the dual-Python setup we're using. We rely on calling pip directly from the shell, which is not a stable symlink. Upgrading pip from either Python 2 or 3 creates a new symlink and it becomes non-obvious which version you're then operating in. To fix this we switch all images to use python -m pip instead of pip, which always gives us a version-appropriate pip version.

[gregdenton]

LGTM.

[sravano9]

After using RUN python -m pip install -U setuptools
still facing same error

Downloading/unpacking setuptools from https://files.pythonhosted.org/packages/7c/1b/9b68465658cda69f33c31c4dbd511ac5648835680ea8de87ce05c81f95bf/setuptools-50.3.0.zip#sha256=39060a59d91cf5cf403fa3bacbb52df4205a8c3585e0b9ba4b30e0e19d4c4b18
Running setup.py (path:/tmp/pip_build_root/setuptools/setup.py) egg_info for package setuptools
Traceback (most recent call last):
File "", line 3, in
File "setuptools/init.py", line 16, in
import setuptools.version
File "setuptools/version.py", line 1, in
import pkg_resources
File "pkg_resources/init.py", line 1365
raise SyntaxError(e) from e
^
SyntaxError: invalid syntax
Complete output from command python setup.py egg_info:
Traceback (most recent call last):

File "", line 3, in

File "setuptools/init.py", line 16, in

import setuptools.version

File "setuptools/version.py", line 1, in

import pkg_resources

File "pkg_resources/init.py", line 1365

raise SyntaxError(e) from e

                        ^

SyntaxError: invalid syntax

[bcipriano]

@sravano9 What platform are you on? Can you share the docker command you're running? These will help me try to reproduce this error.

[sravano9]

@bcipriano I am executing this below command inside docker file
RUN python -m pip install -U setuptools

I am using python version 2.7 and Ubuntu Os

please let me know any changes required

[bcipriano]

Sorry to be clear I mean, can you share the command you're using to actually kick off the docker build. I.e. docker build ....

What version of Ubuntu are you on?

[HuanwenChen312]

Hi, I'm using Bazel Container Image Rules do build and run a python image, I'm also encountering the same issue, I have tried to upgrade setuptools to lates version, but still getting the same error:

raise SyntaxError(e) from e
                       ^
SyntaxError: invalid syntax

Please feel free to let me know if you need any more information, thanks

[bcipriano]

@HuanwenChen312 What's the exact version of Python you're using? I.e. the result if you run python --version within your build environment.