I am running a Laravel application on Kubernetes and currently have a requirement to mount a storage/log folder from multiple pods where all pods will write to the same laravel.log file. To achieve this, I used AWS EFS with the EFS-Provisioner for Kubernetes to mount the storage.

While troubleshooting a logging issue from my application, I noticed that when I log an entry to the laravel.log file from Pod A/B, it shows up in both Pod A/B when I tail the log however it does not show up in Pod C. If I log from Pod C, it will only show up in Pod C. I am working inside the container using php artisan tinker and Log::error('php-fpm'); for example as well as tail -f /var/www/api/storage/logs/laravel.log. The same behaviour happens if I echo "php-fpm" >> /var/www/api/storage/logs/laravel.log.

At first, I thought that I was possibly mounting the wrong storage however if I touch test in the folder, I can see it across Pod A, B, C. I can also see the other log files that are created with identical timestamps.

Any ideas on how to fix this?

Edit: I noticed that pod A, B which are both seeing each others log entries are in the same AZ. Pod C (and another Pod D running Nginx) are running in a different AZ. I just want to outline this, but I feel like this really shouldn't matter. It should be the same storage no matter where you are connecting from.