Vendor PySocks?

[iamthad]

What's the problem this feature will solve?
pip works with a SOCKS proxy if PySocks is installed. On a host which can access the internet only via a SOCKS proxy, it's possible to download get-pip.py e.g. through curl. However, since PySocks is not vendored in pip, running get-pip.py fails with requests.exceptions.InvalidSchema: Missing dependencies for SOCKS support..

Describe the solution you'd like
Consider vendoring PySocks along with urllib3 and Requests to allow better behavior when internet access is only available via a SOCKS proxy.

Alternative Solutions
It is possible to download the necessary packages on an internet-connected host using pip download, tar them up, copy them over via flash drive or scp, and then run get-pip.py with the --no-index and --find-links arguments pointing at these packages. I was able to get a working pip using this process after a couple of attempts.

It's probably also possible to download the necessary wheels manually through PyPI's web interface, but I did not attempt this.

Additional context
While the issue relates to the get-pip bootstrap, it seemed to be appropriate to report the issue on this repository since get-pip.py is just a self-extracting version of pip.

[chrahunt]

PySocks:

• pure Python
• supports Python 2.7 and Python 3.4+
• only dependency is win-inet-pton (for Python 2.7 on Windows)
• BSD 3-Clause (link)

win-inet-pton:

• pure Python (uses ctypes)
• supports Python 2.7
• no dependencies
• "public domain" (link)

[uranusjr]

@chrahut Do you know whether pysocks (or requests, or pip as a whole) behaves correctly on non-Windows platforms if win-inet-pton is installed? This would affect how easy it is to vendor them (since vendored packages would be importatble at all times regardless of platform, and we’d need to patch things if win-inet-pton can only present on Windows).

[chrahunt]

• I was able to successfully install and import win-inet-pton in Ubuntu 18.04 on Python 3.7.2 and 2.7.15.
• PySocks guards the import of win-inet-pton behind a platform check here.
• win-inet-pton also does a platform check here and importing it is a no-op otherwise.

Nothing else in pip references win-inet-pton, so given the above I think the non-Windows behavior should be the same.

[uranusjr]

Nice! It seems the vendoring would not be too complicated then. I’ll leave it to the core devs to decide whether to do it (I’m personally +0 because why not; the only downside is probably package size).

[pradyunsg]

I don't have any major concerns with this.

Mostly, just the regular considerations with vendoring packages apply:

• is it big?
• is it a blocker?
• does it depend on some C extension? i.e. not pure Python?
• cross platform support?
• how sustainable/stable is the project?

[pradyunsg]

/me hates GitHub's mobile UI.