Provide upload rights to a user to a www directory

How to provide upload rights to a user to a www directory?

If you have a Google Cloud instance running Centos-7, have setup SFTP on your machine and are now wondering how to provide access to the www folder to your www admin, here are the steps to follow.

Step 1 is to create a unique group, or use an existing group like "apache"

Next, add the group name to the folder you want to share, using 
sudo chgrp -R apache

Step 3 is to add rwx permissions [read, write, execute] to the group, on the shared folder.
You can do that with the command
sudo chmod -R g+rwx

Finally, add the user with whom you want to share the folder to the group, using the command
usermod -a -G apache

After this is done, your user will be a part of the apache group, which will have read, write and execute permissions to the www folder.

You can add additional users to the group apache, which will allow them access to those folders, automatically.

Ref:
Here is a link on allowing a group read write access to a directory
allowing-a-group-read-write-access-to-a-directory

Here is a detailed explanation on how to add a user to a group
add-a-user-to-a-group-or-second-group-on-linux