File Upload Permissions error in Nginx, PHP

Question

I'm running a local nginx server with php to write a piece of code which basically has an upload functionality. I need to upload images to a folder tmp and then work on. But I guess there are some issues with the folder permissions coz php is sending back an error UPLOAD_ERR_CANT_WRITE .

ls -l in the directory:

drwxr-xr-x 2 root  root      4096 Mar 22 19:20 assets
-rw-r--r-- 1 root  root      1564 Mar 22 19:20 cropper.php
drwxr-xr-x 5 root  root      4096 Mar 22 19:20 files
drwxr-xr-x 2 root  root      4096 Mar 22 19:20 images
-rw-r--r-- 1 root  root     10018 Mar 22 19:20 index.htm
-rw-r--r-- 1 root  root      7972 Mar 22 19:20 second-page.php
drwxrwxr-x 2 arjun www-data  4096 Mar 22 19:20 tmp

i tried to change permissions around but they keep on failing. So how do I get out of this mess?

Answer 1

be sure php runs as www-data group. It should not. Look in config for "Group".

Easy way is

ps aux|grep php

look php daemon user and chown tmp folder to that user.

remember php usually not run by same user as nginx, they are different processes

Answer 2

Although the Group Permission is set to www-data the User is looks to still be assigned to yourself. If you cd to the directory and run chown -Rf www-data:www-data it will set the owner of the tmp directory to the web server, and should then allow php to write to that folder.

Answer 3

=> php-fpm needs write access, not nginx. php-fpm process running as uid 1000, not as www-data

so you could chgrp -R 1000 tmp

ideally you would limit what directory www-data and php-fpm have write access to, Likewise limit it to an upload directory for example in WordPress.