Add a verify_sendgrid_webhook_signature decorator to make Sendgrid Events webhook development easier

[blag]

Add a decorator that verifies the webhook signature for Sendgrid Events.

See: https://www.twilio.com/docs/sendgrid/for-developers/tracking-events/getting-started-event-webhook-security-features#sample-verification-libraries for more information.

Added tests and documentation.

[sklarsa]

This looks like a cool effort, thanks! Just please make sure that we support the Sendrid API versions that implement the webhook signature before spending more time on this. All supported sendgrid/django/python versions can be found in our test matrix

[blag]

Sendgrid v5 doesn't have any support for webhooks. I'm not sure how to skip tests (and imports, etc.) when the sendgrid package version < 6.

But the tests with sendgrid v6 all pass when I run tox locally.

Any advice or ideas?

[sklarsa]

Sendgrid v5 doesn't have any support for webhooks. I'm not sure how to skip tests (and imports, etc.) when the sendgrid package version < 6.

But the tests with sendgrid v6 all pass when I run tox locally.

Any advice or ideas?

I have some utils for that. You can see the usage here:

django-sendgrid-v5/test/test_mail.py

Lines 21 to 24 in 5188d58

	from sendgrid_backend.util import SENDGRID_5, SENDGRID_6, dict_to_personalization
	if SENDGRID_6:
	from sendgrid.helpers.mail import Bcc, Cc, To

[blag]

Thanks for the pointers, got all the tests passing. This should be good to merge.

[sklarsa]

lgtm, thank you! I'll cut a release shortly