• I'm submitting a ...

  • bug report
  • feature request

• Description
  A couple of days back, plotly CDN was down for hours, leaving even plotly's website not functional(links below). I have many folks on the community forum requesting solutions. I propose support for other CDNs, such as Cloudflare. In some cases, devs might need to host a custom build of plotly.js, but there is no provision to use a CDN. It would be great if devs could choose either plotly, cloudflare or custom(pass your URL) as CDN providers.

• Current behaviour?
  Only plotly's default CDN is an option. If there is any issue with the CDN, the charts don't work.

• Expected behaviour?
  Devs should have options to choose from multiple CDNs. In case of such events, a custom CDN can also be used to keep applications functional.

• Resources/References
  Here are some links to the recent incidents:

  • https://community.plotly.com/t/plotly-js-cdn-down/76253/20
  • 403: Forbidden Error - Plotly unavailable now for download/use? plotly.js#6648
  • CDN down plotly.py#4253

If devs are aligned, I am happy to submit a PR.