Codeigniter – The upload destination folder does not appear to be writable
If the folder is for loading files by users than permisision 777 is required.
It's up to you to validate what files are loaded through upload script. Also you can use .htaccess to alow or not alow certain files to be executed from that directory.
The documentation for upload in codeigniter it's pretty simple and intuitive. Also here you can look at some ways to validate the type of files that are uploaded https://codeigniter.com/userguide3/libraries/file_uploading.html
In my NGINX + PHP-FPM installation the issue was solved changing the SElinux parameters from enforcing to permissive:
edit and change options with vi /etc/selinux/configapply options without restart with sudo setenforce 0check the status with sestatus.
I don't think so giving any folder on server 777 permission is good. Instead giving 777 permission i suggest make www-data user as owner of desired folder and give 755 permission like below
chown -R www-data:www-data /var/www/html/uploads/For 755 permission
chmod 755 -R /var/www/html/uploads/