Cache-control headers not added on azure linux app service - azure

Question

I host an angular frontend inside an Azure App Service on Linux. Stack is Node 12.
In order to enable the response headers "Cache-Control" for the static files I have added the line
<clientCache cacheControlMode="UseMaxAge" cacheControlMaxAge="3.00:00:00" />
inside the Web.config file as suggested in the microsoft documentation here
The Web.config file looks like this:
<configuration>
<system.webServer>
<handlers>
<clear />
<add
name="StaticFile"
path="*" verb="*"
modules="StaticFileModule,DefaultDocumentModule,DirectoryListingModule"
resourceType="Either"
requireAccess="Read" />
</handlers>
<staticContent>
<mimeMap fileExtension=".json" mimeType="application/json" />
<mimeMap fileExtension=".*" mimeType="application/octet-stream" />
<clientCache cacheControlMode="UseMaxAge" cacheControlMaxAge="3.00:00:00" />
</staticContent>
<rewrite>
<rules>
<rule name="redirect all requests" stopProcessing="true">
<match url="^(.*)$" ignoreCase="false" />
<conditions logicalGrouping="MatchAll">
<add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" pattern="" ignoreCase="false" />
</conditions>
<action type="Rewrite" url="index.html" appendQueryString="true" />
</rule>
</rules>
</rewrite>
</system.webServer>
Unfortunately the headers are not set correctly. Is there something wrong with the Web.config file? Does the Azure App Service on Linux have to do something with it?

Answer 1

The web.config file is only for IIS configuration system, but IIS is not for Linux.
So you could not set the cache-control header in web.config file.
If you have entity instance for Linux, you could use Apache .htaccess file:
<IfModule mod_headers.c>
Header set Cache-Control "no-cache, no-store, must-revalidate"
Header set Pragma "no-cache"
Header set Expires 0
</IfModule>
If you don't have entity instance for Linux, you could set the header in code:
response.setHeader("Cache-Control", "no-cache, no-store, must-revalidate"); // HTTP 1.1.
response.setHeader("Pragma", "no-cache"); // HTTP 1.0.
response.setHeader("Expires", "0"); // Proxies.
I have tried using .htaccess file on Azure, but it did not work as Azure is a PaaS, which did not include a entity instance.