Feature Request: Cache-Control Header For Static Files

[EmperorArthur]

Is there an existing issue for this?

• I have searched the existing issues

Is your feature request related to a problem? Please describe the problem.

When serving static files, I want to tell the browser how to handle caching, instead of letting it do whatever it pleases.

While StaticFileMiddleware does set some caching headers, "Cache-Control" is not among them.

This is similar to #44153, but I would like to instruct the browser in production that files should not be expected to change for a significant period of time.

Describe the solution you'd like

Originally posted by @Tratcher in #44153

• Add string? CacheControl to StaticFileOptions

• Set this to Cache-Control: max-age=0, must-revalidate in the default host builder for IsDevelopment, but make sure it's easy to override for other environments.

This would allow easily setting the header per environment with only single line of code.
builder.Services.Configure<StaticFileOptions>(builder.Configuration.GetSection("StaticFileOptions")

Additional context

Work-arounds do exist, but are not ideal compared to something integrated.

[EmperorArthur]

An more generic solution would be to add Dictionary<string, StringValues>? ExtraHeaders to StaticFileOptions, but that seems too generic for a very specific problem.

[nithyav2017]

I would like to work on this issue and submit PR that adds header "Cache-Control:no-cache" header for static files in development.

As you mentioned , I will define a new string? CacheControl property in StaticFileOptions.cs, allowing configuration via appsettings.json like

"StaticFileOptions": {
  "CacheControl": "max-age=0, must-revalidate"
}

This can be set per environment (ex. development or Production), and I'll wire it up in the program.cs using:

builder.Services.Configure<StaticFileOptions>(
    builder.Configuration.GetSection("StaticFileOptions"));

Let me know If that direction works.

[EmperorArthur]

That sounds great to me, but it's not my decision to make. I say go for it!

Should be pretty simple to do code wise, but I'm not sure about tests.

1. Add the item to StaticFileOptions.cs.
2. Add responseHeaders.Headers.CacheControl = _options.CacheControl here.

[nithyav2017]

Thank you!, I wanted to test this properly, but unfortunately the Aspnetcore solution is not building successfully on my local machine yet. I have already raised an issue regarding the build problem here: #64231

Once the source is building , I can proceed with implementing and testing the PR.