Thumbnails not generated with Kirby CMS on CloudPanel

[Nemesis]

I’m hosting multiple Kirby websites using CloudPanel on a Debian 11 server with Apache. Everything runs smoothly except for one critical issue:
Thumbnails are not being generated.
There are no errors in the logs. However, Kirby reports missing media files when I visit pages that should display images.
Here's what I’ve tried so far:

• Both ImageMagick (v7.1) and GD (2.3) are installed and enabled for PHP 8.1.
• Permissions are set to 755 for folders and 644 for files.
• File ownership is siteowner:siteowner, as per CloudPanel defaults.
• Thumbnails from the Blurry Placeholder plugin are generated correctly.
• The /usr/local/bin/convert binary exists and works when executed manually.
• I’ve tried setting both GD and ImageMagick drivers in config.php, but thumbs still don’t generate.

Have you seen this before?

 

[Rootali]

Yes, I’ve run into this exact issue when deploying Kirby with CloudPanel. It can be tricky because everything looks fine but thumbs silently fail.
Here’s what I’d recommend:

1. Test exec() inside Kirby
   Add this to a template to see if exec() actually works:
   
   

   exec('whoami', $output, $retval);
   dump($output);
   dump($retval);

2. Check if your PHP user can run convert
   Even if convert works from your shell, the PHP user (usually siteowner) might not have execution permission. Try running:
   
   

   su - siteowner
   convert input.jpg output.png

 

[Nemesis]

I tested exec('whoami') from a Kirby template—it returns siteowner, which is correct. Also, running convert directly as siteowner works just fine.
Still, Kirby doesn’t generate thumbnails even though the Placeholder plugin does. Could it be a driver problem?

 

[Rootali]

Good job narrowing that down.

Yes, it might be related to how Kirby’s thumb generation is triggered. A few more things to check:

1. Make sure Kirby is actually calling the thumbs method.
   In your template, I noticed you’re using:
   
   

   <img src="<?= $image->placeholderUri() ?>" data-src="<?= $image->url() ?>" />

   This loads the original image, not a generated thumb. Try changing to:
   
   

   <img src="<?= $image->thumb()->url() ?>" />

2. Thumbs are generated only when the URL is called.
   Make sure the image URL is actually accessed from the browser at least once.

 

[Nemesis]

You’re right—I was never explicitly calling the thumb() method in my templates. I’ve updated the template to use it directly.
However, I still don’t see the generated thumbnails in the /media folder, even after visiting the image pages.

 

[Rootali]

If you're calling thumb() but still not seeing results, here’s one last thing that tripped me up:

CloudPanel's Nginx/Apache config may block access to image types​

Check if you have this block in your Nginx/Apache config:

location ~* ^.+\.(css|js|jpg|jpeg|gif|png|ico|svg|webp|...)$ {
add_header Access-Control-Allow-Origin "*";
expires max;
access_log off;
}

It may silently block dynamic image requests like thumbs. Try commenting it out or making sure it doesn’t interfere with Kirby’s /media folder.

 

[Nemesis]

Boom. That was it.

There was a broad location rule in the Nginx config that unintentionally blocked access to the dynamically generated files. Once I adjusted it, thumbs started working perfectly — both in the Panel and frontend.

Thanks again, Rootali. You saved me hours of frustration.

 

[Rootali]

Anytime, Nemesis. Glad it’s sorted!
CloudPanel is powerful but needs a bit of tweaking for things like Kirby.
Let me know if you run into anything else!