nginx: add Cache-Control header

[deer-wmde]

https://phabricator.wikimedia.org/T331423

Adds the Cache-Control header to the nginx response. Forces revalidation for index.html

[github-actions]

Deployment previews on netlify for branch refs/pull/791/merge will be at the following locations (when build is done):

• UI with mock store: https://ef7b60a5c8-mock--wbstack-ui.netlify.app/
• UI pointing to prod: https://ef7b60a5c8-prod--wbstack-ui.netlify.app/

[m90]

I would think we still need to set different values for assets that are not index.html, i.e. revisioned JS and CSS assets that will never change and thus can be cached:

JS and CSS bundles are revisioned by the build system. However, we do not send a Cache-Control header here either. As these files will never change after being created (as opposed to index.html), we can set "hard" cache control values to make sure users will never have to redownload the same bundle twice. Something like Cache-Control: max-age: 31536000, immutable should work well.

[deer-wmde]

I wonder if we should lower the max-age for everything else though. I'm thinking of assets like images that may not change their filename (I think?)

[m90]

I'm thinking of assets like images that may not change their filename (I think?)

A cursory check tells me all assets that are handled by the Vue App are revisioned. We do load some stuff from GCS as well, but those aren't affected by this change anyways.

[deer-wmde]

I'm thinking of assets like images that may not change their filename (I think?)

A cursory check tells me all assets that are handled by the Vue App are revisioned. We do load some stuff from GCS as well, but those aren't affected by this change anyways.

Indeed! I didn't know this, amazing. In that case we should be good, thanks for mentioning this

[m90]

Indeed! I didn't know this, amazing. In that case we should be good, thanks for mentioning this

Unfortunately I was wrong and we're serving an unrevisioned /config.js file which we'll need to handle just like index.html I would assume.

[m90]

Works well for me when testing this locally.

On subsequent loads, index.html and config.js will be requested from the server, yielding a 304 response, all other assets will skip the request, reading from disk cache.

When adding arbitrary changes, I will the correct version after reload.