AWS EC2: hostname reverts to xxxxxx.ec2.internal on boot. Is it a problem?

pandalion98

Registered
Aug 26, 2015
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2
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General Santos
cPanel Access Level
Root Administrator
I've tried different methods to make the hostname permanent including but not limited to changing /etc/sysconfig/network, using the hostname command, and using the "change hostname" feature within WHM. It reverts back to EC2's default format "ip-123-123-123-123.ec2.internal".

It doesn't seem to hurt anything. All of my sites still work and WHM/cPanel is still fully accessible.

Should I just leave it like that or should I make the hostname the same as the address I use to access it (server.domain.com)?

Some system info:
Code:
grep '' /etc/redhat-release /usr/local/cpanel/version /var/cpanel/envtype ; grep CPANEL= /etc/cpupdate.conf ; httpd -v ; php -v ; mysql -V

/etc/redhat-release:CentOS Linux release 7.2.1511 (Core)
/usr/local/cpanel/version:11.56.0.9
/var/cpanel/envtype:xen hvm
CPANEL=release
Server version: Apache/2.4.18 (Unix)
Server built:   Apr  9 2016 10:23:37
Cpanel::Easy::Apache v3.32.12 rev9999
PHP 5.6.20 (cgi-fcgi) (built: Apr  9 2016 10:27:21)
Copyright (c) 1997-2016 The PHP Group
Zend Engine v2.6.0, Copyright (c) 1998-2016 Zend Technologies
    with Zend OPcache v7.0.6-dev, Copyright (c) 1999-2016, by Zend Technologies
mysql  Ver 14.14 Distrib 5.6.30, for Linux (x86_64) using  EditLine wrapper
 

pandalion98

Registered
Aug 26, 2015
4
2
3
General Santos
cPanel Access Level
Root Administrator
The weird hostname was causing havoc on the mail system. Therefore, ignoring the hostname is NOT okay. However, it has been resolved in a recent ticket.

Here's what he instructed me to do:
Looking at the instructions for CentOS 7 for AWS, it looks like you also need to update the /etc/cloud/cloud.cfg file to preserve the hostname. This is that section.

Update the /etc/cloud/cloud.cfg file on your RHEL 7 or Centos 7 Linux instance.
Code:
sudo vim /etc/cloud/cloud.cfg
Append the following string at the bottom of the file to ensure that the hostname is preserved between restarts/reboots.
Code:
preserve_hostname: true
Save and exit the vim editor.

This page shows all of the steps that you need to take to do that on CentOS 7.

Amazon EC2 Linux Static Hostname RHEL7 Centos7
And the hostname doesn't change now.
 
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cPanelMichael

Administrator
Staff member
Apr 11, 2011
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I'm happy to see the issue is now resolved. Thank you for updating us with the outcome.