On a new fresh slice at the Rackspace Cloud, you will find that, by default, there is a firewall blocking everything but port 22, for ssh. When you try to install and start Apache, nothing happens. The firewall is blocking any incoming http connections to our server.
The first thing that you do is setup a rule to allow connections over port 80 in your IPtables file.
Add the following line somewhere above the last REJECT line, I put mine right below my port 22 rule.
-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT
Once you do this, all that is left is to restart iptables.
…and if you haven’t done so already, start apache and set chkconfig on so that it the service starts on boot.
sudo /etc/init.d/httpd start
sudo /sbin/chkconfig httpd on
Hope that helps somebody.