apache - RHEL + PHP : writing files outside /var/www/html?

Question

I'm trying to open a file for read/write. I've been developing on Ubuntu, and have had no problems whatsoever. Now it's time to deploy to the RHEL server, and I discover there seems to be some kind of restriction on the location of a file to be written.

On RHEL, I can't open the file unless it's under /var/www/html. I can't figure out how to allow other locations. I need to manipulate files on a different volume, for disk space management reasons.

The following is the bit of code that works fine on Ubuntu no matter what, but breaks on RHEL if the file is outside the web root:

$repometa = fopen( "/path/to/file/it/does/exist/and/has/good/perms", "r+b");

The actual error is as follows, which is weird, because the permissions are just fine (owned by the "apache" user, with 0644 perms on file, 755 on dirs).

fopen(<thefile>): failed to open stream: Permission denied

Can someone point me to the documents that describe how to un-break RHEL's Apache/PHP config to allow writing to alternate locations on the file system?

Thanks, ~ Paul

Answer 1

As written in the httpd_selinux(8) man page, you must give files and directories specific file contexts if you want to be able to read from or write to them. See the man page for details, keeping in mind that PHP scripts run as the daemon unless you have specifically set up PHP to run as CGI.