Wordpress Docker - How to set memory_limit, max_upload_size and other resource limits

To set max_upload_size and post_max_size to set in the official docker image, open a bash session and run:

root@f125876a0568:/var/www/html# echo “php_value upload_max_filesize 256M” >> .htaccess
root@f125876a0568:/var/www/html# cat .htaccess
# snipped
php_value post_max_size 256M
php_value upload_max_filesize 256M

Using >> in the echo command will append the line to the existing content present.