DeprecationWarning from urllib3

[embray]

Describe your environment

• Operating System version: Linux 78a95de467b6 4.15.0-123-generic #126-Ubuntu SMP Wed Oct 21 09:40:11 UTC 2020 x86_64 GNU/Linux
• Firebase SDK version: admin-python 4.3.0
• Library version: 4.3.0
• Firebase Product: auth

Describe the problem

Steps to reproduce:

urrlib3 version 1.26 introduced a new argument allowed_methods to urllib3.Retry and deprecated the method_whitelist argument, which is still used in firebase_admin._http_client.

Installing urllib3>=1.26 results in the DeprecationWarning when using any part of the library that imports firebase_admin._http_client.

Possible solutions:

• Use one spelling or the other depending on detection of urllib3 version
• Pin required version of urllib3<1.26
• Change the argument used here and pin required version of urllib3>=1.26

[hiranya911]

We currently don't have a direct dependency on urllib3. We just use whatever requests provides us.

from requests.packages.urllib3.util import retry

It seems requests already defines constraints on this dependency, but allows 1.26 of urllib3: https://github.com/psf/requests/blob/c2b307dbefe21177af03f9feb37181a89a799fcc/setup.py#L47

I'm currently leaning towards the first option you've suggested.

from requests.packages import urllib3

_, minor, _ = urllib3.__version__.split('.')
if int(minor) < 26:
  # use old format
else:
  # use new format

Will take another close look at this after this after the holidays.

[xmo-odoo]

Checking, are there news on the subject?

Also @hiranya911 as-given the solution seems risky: the parameter is slated for removal in urllib3 2.0, which would have a minor version < 26, so going with a version check, the entire thing should probably get checked.

Alternatives:

• inspect the signature of the ctor, and use allowed_methods if it's present
• try to create the Retry object with allowed_methods, and fall back on method_whitelist if that raises a TypeError

Since this is to create a top-level constant, the cost of a try/except should not really be significant.

[pquentin]

Right, please sniff features instead of versions. As recommended in urllib3/urllib3#2057 (comment), using this would be safer:

use_allowed_methods = hasattr(urllib3.util.Retry.DEFAULT, "allowed_methods")

[hiranya911]

Would anybody like to send a quick PR for this?

[xmo-odoo]

@hiranya911 #532