Set a custom static hostname

You can configure a custom hostname that continues to be used during instance recycle.

1. Update the hostname configuration

   Edit the system hostname and hosts files so the hostname persists:

   sudo gedit /etc/hostname /etc/hosts

2. Apply a persistent custom hostname

   Use the following script to define and persist a custom hostname:

   #!/bin/bash
   CUSTOM_HOSTNAME="my-custom-hostname"
   echo "preserve_hostname: true" > /etc/cloud/cloud.cfg.d/99_persist_hostname.cfg
   echo "$CUSTOM_HOSTNAME" > /etc/hostname
   sed -i "s/^127\.0\.0\.1.*/127.0.0.1 localhost $CUSTOM_HOSTNAME/" /etc/hosts
   hostnamectl set-hostname "$CUSTOM_HOSTNAME"

   This configuration prevents cloud‑init from resetting the hostname during future lifecycle events.

Use a hostname based on the original private IP address

If you want the hostname to reflect the instance’s original private IPv4 address, make sure private IP persistence is enabled and configure the hostname dynamically.

1. Retrieve the instance private IP

   Use the AWS instance metadata service to get the private IPv4 address:

   • Instance metadata service (linked to https://169.254.169.254/latest/meta-data/local-ipv4)
     
     

2. Enable private IP persistence

   In the Flexera console, open the stateful node configuration:

   • Select Actions > Edit configuration

   • Go to Persistent resources > Network

   • Enable Persist private IP and enter the IP address
     
     

3. Update the user data script

   In the Flexera console, go to Actions > Edit configuration > Initialization and termination.

   Add the following script to User data:

    #!/bin/bash
   PRIVATE_IP=$(curl -s http://169.254.169.254/latest/meta-data/local-ipv4)
   AWS_HOSTNAME="ip-$(echo $PRIVATE_IP | tr '.' '-')"
   echo "preserve_hostname: true" > /etc/cloud/cloud.cfg.d/99_persist_hostname.cfg
   echo "$AWS_HOSTNAME" > /etc/hostname
   sed -i "s/^127\.0\.0\.1.*/127.0.0.1 localhost ${AWS_HOSTNAME}/" /etc/hosts
   hostnamectl set-hostname "$AWS_HOSTNAME"

   Because the hostname is derived from the persistent private IP, it remains consistent during instance replacement.

Supported operating systems

Hostname persistence is supported on the following operating systems:

• RHEL 7, 8, and 9

• CentOS 7, 8, and 9