Hostname updating problem with CentOS 7 RHEL 7 in AWS EC2

In CentOS 7 and RHEL 7 some times , we have faced hostname updating issue, i had got same issue in AWS EC2 where DHCP configures on CentOS 7, when i attempted a few time in different ways to set hostname with hostname file (/etc/hostname ) and through hostnamectl command , but after reboot hostname get same as earlier because DHCP overwrite the hostname on reboot .

I got solution after spending some of hours and the cloud-init was the reason behind this issue. cloud-init is an organization consolidated with most EC2 AMIs , including AMI Linux and CentOS .

I have found two method , which have solved this issue.

SOLUTION 1 :

You need to edit “/etc/cloud/cloud.cfg ” and comment out modules that set the hostname .The accompanying modules can be remarked out utilizing #.

#vim /etc/cloud/cloud.cfg

# -  set_hostname
# - update_hostname

Now change your hostname thorough hostnamectl or edit the hostname file /etc/hostname like below.

#hostnamectl set-hostname server1.example.com

#hostnamectl

After that reboot the server.

# systemctl reboot

SOLUTION 2:

You can override hostname name with your preferred hostname with below steps.
(1) Create a file in like 99_anyname.cfg in “/etc/cloud/cloud.cfg.d/” and write like below content.

#cloud-config
hostname: server1
fqdn : server1.example.com

P.S : Here server1 and server1.example.com are hostname and fqdn.

(2) Set the permission and if selinux is enabled or in enforcing then set selinix context like below.

#chown root: /etc/cloud/cloud.cfg.d/99_anyname.cfg
#chmod 644 /etc/cloud/cloud.cfg.d/99_anyname.cfg

If selinux in enforcing mode then execute below command and check correct file name.

#chcon system_u:object_r:etc_t:s0 /etc/cloud/cloud.cfg.d/99_anyname.cfg

(3) Reboot the server and after reboot you check now hostname .

Hostname updating problem with CentOS 7 RHEL 7 in AWS EC2