What's the best way of handling permissions for apache2's user www-data in /var/www?

Question

Has anyone got a nice solution for handling files in /var/www/ ?
We're running Name Based Virtual Hosts and the apache2 user is 'www-data'

We've got two regular users & root. So when messing with files in /var/www ,rather than having to...

chown -R www-data:www-data

...all the time, what's a good way of handling this?

Supplementary question. How hardcore do you then go on permissions?

This one has always been a problem in collaborative development environments.

Cheers.

Answer 1

Attempting to expand on @Zoredache's answer, as I give this a go myself:

• Create a new group (www-pub) and add the users to that group

  groupadd www-pub

  usermod -a -G www-pub usera ## must use -a to append to existing groups

  usermod -a -G www-pub userb

  groups usera ## display groups for user

• Change the ownership of everything under /var/www to root:www-pub

  chown -R root:www-pub /var/www ## -R for recursive

• Change the permissions of all the folders to 2775

  chmod 2775 /var/www ## 2=set group id, 7=rwx for owner (root), 7=rwx for group (www-pub), 5=rx for world (including apache www-data user)

  Set group ID (SETGID) bit (2) causes the group (www-pub) to be copied to all new files/folders created in that folder. Other options are SETUID (4) to copy the user id, and STICKY (1) which I think lets only the owner delete files.

  There's a -R recursive option, but that won't discriminate between files and folders, so you have to use find, like so:

  find /var/www -type d -exec chmod 2775 {} \;

• Change all the files to 0664

  find /var/www -type f -exec chmod 0664 {} \;

• Change the umask for your users to 0002

  The umask controls the default file creation permissions, 0002 means files will have 664 and directories 775. Setting this (by editing the umask line at the bottom of /etc/profile in my case) means files created by one user will be writable by other users in the www-group without needing to chmod them.

Test all this by creating a file and directory and verifying the owner, group and permissions with ls -l.

Note: You'll need to logout/in for changes to your groups to take effect!

Answer 2

I am not entirely how you want the permissions, but this may give you a starting point. There probably are better ways. I am assuming you want both users to be able to change anything under /var/www/

• Create a new group (www-pub) and add the users to that group.
• Change the ownership of everything under /var/www to root:www-pub.
• Change the permissions of all the folders to 2775
• Change all the files to 0664.
• Change the umask for your users to 0002

This means any new file created by either of your users should be username:www-pub 0664 and any directory that gets created will be username:www-pub 2775. Apache will get read access to everything via the 'other users' component. The SETGID bit on the directories will force all files being created to be owned by the group that owns the folder. Adjusting the umask is needed to make sure that write bit is set so that anyone in the group will be able to edit the files.

As for how hardcore I go on permissions. It completely depends on the site/server. If there is only 1-2 editors and I just need to keep them from breaking things too badly then I will go easy. If the business required something more complex then I would set up something more complex.

Answer 3

I think you may find POSIX ACL (access control lists) to be helpful. They allow a finer-grained permission model compared to the user:group:other model. I have found them to be easier to keep straight in my head since I can be more explicit and can also set the "default" behavior for a branch of the file system.

For example, you can specify each user's permissions explicitly:

setfacl -Rm d:u:userA:rwX,u:userA:rwX /var/www
setfacl -Rm d:u:userB:rwX,u:userB:rwX /var/www

Or you can do it based on some shared group:

setfacl -Rm d:g:groupA:rwX,u:groupA:rwX /var/www

And perhaps you want to keep your Apache user as read-only

setfacl -Rm d:u:www-data:rX,u:www-data:rX /var/www

Man pages:

• setfacl
• getfacl

Tutorial

Answer 4

Syaman, look at the different octet values for chmod. Difference being 27 5 5 does not allow writes by group members, while 27 7 5 does.

I agree with David's answer (which meshes with what Zoredache said too).

Grr, I hate that you need x rep to comment, and hence I have to pollute questions with answers-that-are-really-comments until I get there.

Answer 5

On debian lenny, in addition to Tom's post, i had to modify /root/.bashrc umask also to 0002, or www-data won't have a proper umask by just editing umask in /etc/profile .

Answer 6

the accepted anwer works great when dealing with local text-editors (nano running on localhost), but remote editors working via sshfs mounts (ubuntu, mac) seem to do stuff like change the permissions of files upon save -- or, on mac, saving/creating is not "permitted" at all