add support for cloudflare's 3.0 python package

[mahtin]

The following ...

install_requires = [
    'cloudflare>=1.5.1',
    'setuptools>=41.6.0',
]

... in certbot-dns-cloudflare folder needs updating to cloudflare<=2.19.*. This is explained at github.com/cloudflare/python-cloudflare README file. It's become kinda urgent because of a pending 3.x release that's not code compatible. Certbot will continue to be 100% compatible with the 2.19.* releases.

BTW: Upgrading the cloudflare requirements from 1.5.1 to a newer release is highly recommended as big fixes and major improvements (like keepalive etc) are in the newer releases.

[bmw]

thanks for the heads up!

poking around https://github.com/cloudflare/python-cloudflare and in particular cloudflare/python-cloudflare#191 (comment), it sounds like 2.19.* will receive security fixes for 6 months, after which it will be abandoned. we should try to switch over to 3.0 before then

our code supporting both 2.19 and 3.0 may be nice depending on the versions of the cloudflare libraries available in LTS linux distros where the certbot packages are receiving updates. i think ensuring we work with 3.0 is most important though

i updated our setup.py file in #9940. i'll leave this issue open to track the 3.0 compatibility work

[mahtin]

The 2.19.* release(s) will get support from me for quite some time, plus certbot's usage (if I may say) of the Cloudflare API is quite basic (which is a good thing). That said, it's a very stable library and unlikely to need any updates.

For 3.*, when it's released, you can't decide what to do. Cloudflare is the supporting entity for that library. Long term, that's your go-to choice.

[bmw]

got it. thanks for the additional info ❤️

because of that, 3.0 not being out yet, and us having #9940 which should be merged soon, i'm dropping the priority of this slightly. if someone on the certbot team disagrees with this decision, feel free to bump it back up