Improve CSS of static release dashboard

[hugovk]

Visiting the direct URL:

• https://buildbot.python.org/plugins/wsgi_dashboards/release_status/

Is much quicker than:

• https://buildbot.python.org/#/release_status

This is because the latter does nothing on screen for 1.5-4s as it downloads the app shell, a 1.1 MB React bundle, a 1.3 MB dashboard plugin, and then runs the app.

It can be nearly 14s for the whole page to be rendered (uncached) or 4s (cached).

The direct URL can be 5s (uncached) and 3s (cached).

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But the CSS is a bit off for the direct URL, as we don't get the Bootstrap CSS of the full React route.

React route:

Direct URL:

This PR adds some CSS so the standalone dashboard looks better:

[StanFromIreland]

LGTM

[StanFromIreland]

Looks good now!

[vstinner]

But the CSS is a bit off for the direct URL, as we don't get the Bootstrap CSS of the full React route.

Why don't we get the Bootstrap CSS when using the direct URL?

[hugovk]

Because it's all bundled into the Buildbot's stylesheet, which is only referenced from the React app shell. See:

view-source:https://buildbot.python.org/#/release_status

    <link rel="stylesheet" crossorigin href="./assets/index-CQKNRskk.css">

It's 212 KB and includes both Bootstrap and Buildbot CSS.

The direct URL is just the rendered template without the full app.

[vstinner]

Oh ok. Good to know.