preconnect to iframes if applicable

Since stumptown-renderer is stateless and relatively dumb our best bet is to use meta tags for sending pre-fetching type of hints.

When rendering a page that will have <iframe src="https://someotherdomain/... in it, we should inject something like <link rel="preconnect" href="https://someotherdomain/... in the HTML.

[peterbe]

In my quickly whipped up pseudo code I wrote:

image_filename = make_image_filename(interactive_example.url)
# image_filename would now be something like "ab/123/de9abac012.png"
# which might be based on an MD5 of the URL or something. 

Perhaps we can download the content of the iframe and hope that it the content of the referenced external URLs haven’t changed. E.g. in Python:

import hashlib
import requests

def make_image_filename(url):
    hash_ = hashlib.md5()
    hash_.update(requests.get(url).content)
    hash_.update(url)
    sha = hash_.hexdigest()
    return f"v1-{sha[0]}/{sha[1:]}.png"

I need to familiarize myself more with the interactive-example project and what tools are available. If we had a cron job or a webhook or something fancy we can invalidate images based on git commits.

[peterbe]

wouldn’t hurt to add them, but it doesn’t seem to be helping much either

Then let’s not bother. For the benefit of hacking on other cooler things. But let’s not close the issue just yet. Mind you, sometime soon I hope we can turn PRs into fully deployed subdomains. Then we can make one production site with and one without and then it’s be easier to measure.