If you are getting this error but you can curl with localhost you can add nginx to proxy_pass your apache.
Install nginx:
yum install epel-release
yum install nginx
Edit /etc/nginx/nginx.conf
Replace port 80 with 8080
Create a file: /etc/nginx/conf.d/wp.conf with following contents:
server {
listen 8081;
server_name _;
location @wp {
proxy_pass http://localhost:80;
}
location / {
try_files $uri @wp;
}
}
Restart nginx.
Your wordpress site will be available on <IP>:8081