Adding adhoc GitHub script

[domanchi]

Summary

Accidents happen. Sometimes, people write secrets in form fields on Github. However, organizations who subscribe to Github webhooks can scan these fields for secrets, and alert off them appropriately.

This adhoc script enables this functionality, by doing:

from detect_secrets_server.adhoc.github.webhook import scan_for_secrets

def receive_github_event(request):
    try:
        verify_github_webhook(request)
    except Exception as e:
        log_error(e)

    attribution_link = scan_for_secrets(
        request.headers['X-Github-Event'],
        request.json(),
    )
    if attribution_link:
        alert(attribution_link)

I'm uncertain whether this should live in detect-secrets-server or detect-secrets -- I'm open to suggestions for that.

⚠️ Warning! ⚠️

This makes python-crontab an optional dependency. This is because this PR introduces the idea of using detect-secrets-server as a standalone package, that doesn't need to use cron to auto scan repositories.

To address this, I've modified the README to indicate the non-breaking install instruction. However, this will also allow us to install detect-secrets-server with less bloat.

This also depends on Yelp/detect-secrets#287, so I need to perform the appropriate version bumps for necessary tests to pass. However, I thought I'd post the review early on to get comments on it first.

[KevinHock]

looks great so far!! 💯

[KevinHock]

Nit: Could add # For e.g. 'SomeDetector : Bool' output

[KevinHock]

I could be wrong, but I don't think this does what you want it to.

'created' is the return value of .get if 'action' is not a present key.

[domanchi]

Yeah, that's accurate. Some comments don't have action on them, and we want to scan the contents as default behavior.

[KevinHock]

I guess my feedback is since 'created' == 'deleted' will always be false, it feels weird, but not a strong opinion.

[KevinHock]

👍 😄

[KevinHock]

re: regular detect-secrets vs. d-s-s, I think -server is fitting.

We can add a ref to this additional functionality to the d-s readme though, to add SEO to it.