How do I assign a static hostname to a private Amazon EC2 instance running RHEL 7 or Centos 7?

As a Linux System admin, we always love to work on CentOS and RHEL. In my case i had to launch a CentOS7 instance from the AWS Marketplace again. When we set the hostname with hostnamectl and reboot, yes the Instance comes with the default hostname again. So i have thought of documenting it here, so that it may be helpful for you as well !!

Issue

• You have launched a CentOS 7 Instance from AWS Marketplace.
• You have ran hostnamectl and rebooted the instance, but the hostname didnt became persistent.

Solution

• Set hostname with hostnamectl command

  hostnamectl set-hostname server1.example.com

• Assign the hostname in /etc/sysconfig/network file

  vim /etc/sysconfig/network
  NETWORKING=yes
  NOZEROCONF=yes
  HOSTNAME=server1.example.com

• Update the cloud.cfg file and set preserve_hostname to true

  vi /etc/cloud/cloud.cfg
  preserve_hostname: true

• Now reboot the server

  reboot

• The server will bootup with the new persistent hostname. Please comment, if you have faced any issues with this.