Headers don't get set in Laravel 5.6 - php

Question

I'm using Laravel 5.6.
I'm trying to cache my css/js files. The way I'm doing it is using a middleware.
public function handle($request, \Closure $next, $guard = null)
{
$request->header('Cache-Control', 'max-age=86400, public');
$request->header('X-www-test-header', 'test-value');
return $next($request);
}
And wrapping basically every route in this middleware. This seems like a really bad idea from where I'm standing but to be perfectly honest I can't find another way to do it(any suggestions are welcome). But that's not the problem.
The problem is that my headers don't make thru.
I've also tried setting the headers via .htaccess
<IfModule mod_headers.c>
<filesmatch "\.(ico|flv|jpg|jpeg|png|gif|css|swf)$">
Header set Cache-Control "max-age=2678400, public"
</filesmatch>
<filesmatch "\.(html|htm)$">
Header set Cache-Control "max-age=7200, private, must-revalidate"
</filesmatch>
<filesmatch "\.(pdf)$">
Header set Cache-Control "max-age=86400, public"
</filesmatch>
<FilesMatch "\.(js|css)$">
ExpiresActive On
ExpiresDefault "access plus 1 weeks"
</FilesMatch>
That doesn't work either.
I'm honestly not sure what the problem is. Either laravel is somehow rewriting all the headers or apache or something.
Literally any pointing in the right direction is appreciated.

Answer 1

Laravel does not handle assets requests. Those requests are handled by the WEB server.
That's why try to enable apache headers module by executing a command a2enmod headers

Answer 2

The first problem is you are using request header getters to set a header, which won't work of course. So $request->header(key, default) will return the header with the specified key from the request and if that header is not present, the default you specified will be returned.
setting headers on response
return response($content)
->header('Content-Type', $type)
->header('X-Header-One', 'Header Value')
->header('X-Header-Two', 'Header Value');
the above code shows how you should attach header to a response and here is the Laravel documentation on that
Enable caching for static assets
So now if you want to set expiration time on assets so they can be cached, the best way to do so is to utilize your web server. For example if you are using Apache, this tutorial will help.
By the way, you should utilize your web server because for the most part, Laravel doesn't respond to static asset requests (your web server does), unless you specify so.
In short you need to enable to mod_expires module and the configure it bu setting an expiration time
a2enmod expires
and use it as belows
[...]
<IfModule mod_expires.c>
<FilesMatch "\.(jpe?g|png|gif|js|css)$">
ExpiresActive On
ExpiresDefault "access plus 1 week"
</FilesMatch>
</IfModule>
[...]