id,node_id,number,title,user,state,locked,assignee,milestone,comments,created_at,updated_at,closed_at,author_association,pull_request,body,repo,type,active_lock_reason,performed_via_github_app,reactions,draft,state_reason
1154399841,I_kwDOBm6k_c5Ezr5h,1645,"Sensible `cache-control` headers for static assets, including those served by plugins",697092,open,0,,3268330,4,2022-02-28T18:12:03Z,2022-03-08T02:59:29Z,,NONE,,"## What I'm seeing

With `default_cache_ttl = 86400`, I see the following:

A table view returns `Cache-control: max-age=86400`:

![Screenshot_20220228_190000](https://user-images.githubusercontent.com/697092/156034352-4d64683e-39c8-49af-81df-0217a5957bbd.png)

A static asset returns no `Cache-control` header:

![Screenshot_20220228_185933](https://user-images.githubusercontent.com/697092/156034363-d0b03cc2-5889-4ed2-b601-8c1846b8469a.png)

## What I expected to see

I expected the static asset to return a `Cache-control` header indicating that this response can be cached.

## Why this matters

I'm productionising a Datasette deployment right now and was looking into putting it behind a Varnish instance. I was surprised to see requests for static assets being served from Datasette rather than Varnish, this is what led me to look more closely at the response headers.

While Datasette serves those static assets pretty quickly, I don't see why Datasette should serve them. By their nature, static assets like images and JS files are very cacheable, so it should be easy to serve them from a cache like Varnish.

(Note that Varnish can easily be configured to override this header, enabling caching for static assets. But it would be better if this override was not necessary.)

## Discussion

It seems clear to me that serving static assets without a `Cache-control` header is not ideal.

I see two options here:

A. Static assets use the same logic as table / SQL views to set the `Cache-control` header based on `default_cache_ttl`.
B. An additional setting for static assets is introduced (`default_static_cache_ttl`, say).",107914493,issue,,,"{""url"": ""https://api.github.com/repos/simonw/datasette/issues/1645/reactions"", ""total_count"": 1, ""+1"": 1, ""-1"": 0, ""laugh"": 0, ""hooray"": 0, ""confused"": 0, ""heart"": 0, ""rocket"": 0, ""eyes"": 0}",,