An upgrade to Centos 6.6 seems to relabel the standard directories used by nginx with "httpd_" tags.

I have two Centos systems nginx installed from the nginx repo. Both were at version 6.5 and showed,

ls -lZ /etc/nginx/
drwxr-xr-x. root root system_u:object_r:etc_t:s0 conf.d
. . .
-rw-r--r--. root root system_u:object_r:etc_t:s0 nginx.conf
. . .
and
ls -lZ /var/log/nginx/
. . .
-rw-r-----. webs adm unconfined_u:object_r:var_log_t:s0 error.log
. . .

Then I updated one system to Centos 6.6. Nothing else. I didn't change nginx at all, just ran "yum update". Then
ls -lZ /etc/nginx
drwxr-xr-x. root root system_u:object_r:httpd_config_t:s0 conf.d
. . .
-rw-r--r--. root root system_u:object_r:httpd_config_t:s0 nginx.conf
. . .
ls -lZ /var/log/nginx/
. . .
-rw-r-----. webs adm unconfined_u:object_r:httpd_log_t:s0 error.log
. . .

If I use anything outside of the standard locations I must label it myself or an nging restart will fail. For example, my socket for php-fpm fails. I place logs in a different directory (not /var/log/nginx/) and so they fail too.