Google Compute Engine: how to set hostname permanently?

Question

How do I set the hostname of an instance in GCE permanently? I can set it via hostname,but after reboot it is gone again.

I tried to feed in metadata (hostname:f.q.d

Answer 1

The most simple way to achieve it is creating a simple script and that's what I have done.

I have stored the hostname in the instance metadata and then I retrieve it every time the system restarts in order to set the hostname using a cron job.

$ gcloud compute instances add-metadata <instance> --metadata hostname=<new_hostname> 
$ sudo crontab -e

And this is the line that must be appended in crontab

@reboot hostname $(curl --silent "http://metadata.google.internal/computeMetadata/v1/instance/attributes/hostname" -H "Metadata-Flavor: Google")

After these steps, every time you restart your instance it will have the hostname <new_hostname>. You can check it in the prompt or with the command: hostname

Answer 2

Im not sure I understand Adrián's answer. It seems overly complex since you have to run a script each boot why not just use hostname?

vi /etc/rc.local

add:

hostname your_hostname

thats it. tested and working. no need to fiddle with metadata and such.

Answer 3

You can also create a simple startup-script to do the jobs:

$ gcloud compute instances add-metadata <instance-name> --zone <instance-zone> --metadata startup-script='#! /bin/bash 
hostname <hostname>'

Notice that if you already have a startup-script you need to add to the existing startup-script below command or you will replace all the startup-script:

$ hostname instance-name

Answer 4

An easy way to fix this is to set up a startup script with custom metadata.

Key :startup-script 
Value: 
#! /bin/bash 
hostname <desired hostname>

Answer 5

In my CentOS VMs I found that the script /etc/dhcp/dhclient.d/google_hostname.sh, installed by the google-compute-engine RPM, actually changed the hostname. This happens when the instance gets its IP address during boot.

While it's not the long-term solution I really want, for now I simply deleted this script. The hostname I set with hostnamectl now persists after a reboot.

The script is likely to be in exactly the same place in Debian/Ubuntu VMs, but of course I don't run any of those.

Answer 6

I was lucky to set hostname at GCE running CentOS. Source: desantolo.com

1. Click EDIT on your instance
2. Go to "Custom metadata" section
3. Add hostname + your.hostname.tld (change "your.hostname.tld" to your actual hostname
4. run curl --silent "http://metadata.google.internal/computeMetadata/v1/instance/attributes/hostname" -H "Metadata-Flavor: Google"
5. run sudo env EDITOR=nano crontab -e to edit crontab
6. add line @reboot hostname $(curl --silent "http://metadata.google.internal/computeMetadata/v1/instance/attributes/hostname" -H "Metadata-Flavor: Google")
7. On your keyboard Ctrl + X
8. On your keyboard hit Y
9. On your keyboard hit Enter
10. run reboot
11. after system rebooted, run hostname and see if your changes applied

Good luck!