Static files are treated as dynamic content and therefore not served from cache

[Phoenix359]

IIS on Azure is either not caching the crompessed static files after a request or it is not serving them from the cached location on subsequent requests. I have tryed to set the "directory" tag with the most common value in the applicationHost.xdt but that did not work.

Old:
<httpCompression>

New:
<httpCompression directory="%SystemDrive%\inetpub\temp\IIS Temporary Compressed Files">

[shibayan]

No configuration is required as XDT retains the App Service default settings.

[Phoenix359]

Thx for the fast reponse!

I did some extra digging and found out that my static files are not identified as static at all. The request:
GET app.bundle.min.js?v=69YZmh... is treated as dynamic content and therefore is compressed with the lvl set by the dynamicCompressionLevel attribute and is not added to the cache.
I tryed to remove the two javascript mimeTypes from the dynamicTypes node but then no compression is being performed. I tryed to add the element:
<urlCompression doStaticCompression="true" doDynamicCompression="true" />
but that did not help either. I now suspect that the cache busting query string is causing IIS to see this as dynamice content. Is this something this extension can help with or do i need to call on the azure CDN to help me cache my static (versioned) content?

[shibayan]

IIS static content compression may only be used for frequently accessed files.
It may not be working properly with App Service in the first place. Possibly another problem with brotil compression.

[Phoenix359]

I now partially solved this issue by pre-compressing (Gzip & Brotli) all my static files on build with some Gulp tasks and use the nuget package CompressedStaticFiles to serve these pre-compressed static files.
These files are probably not served from server cache but i can leverage Azure CDN for that.

For the dynamic content compression i still use this extension.

[franzo]

adding a rewrite rule to strip the query string works around the issue, e.g.

<rule name="Strip query string to allow static compression" stopProcessing="true">
    <match url="^static/css/(.*)" />
    <action type="Rewrite" url="{PATH_INFO}" appendQueryString="false" />
</rule>