ansible-playbook-change-hostname

A ansible playbook to help fix /etc/hosts

Overview

This was created from some snippets I found online and put it all together in a single place. This is really just here for my own reference.

Here are the links that I owe credit to:

• https://support.ansible.com/hc/en-us/articles/201958037-Reboot-a-server-and-wait-for-it-to-come-back

Howto use this playbook

Define an inventory file in your current directory

[all]
foo-app-01.example.com
foo-app-02.example.com
foo-app-03.example.com
foo-app-03.example.com

So, in order for this to work foo-app*.example.com must be resolvable by DNS and these are the values you want your hostnames to become. If your hosts are not resolvable in DNS you can create a node alias in your inventory file as follows.

[all]
foo-app-01.example.com  ansible_ssh_host=1.2.3.4
foo-app-02.example.com  ansible_ssh_host=1.2.3.5
foo-app-03.example.com  ansible_ssh_host=1.2.3.6
foo-app-03.example.com  ansible_ssh_host=1.2.3.7

After your hostnames are updated, you can also pass a parameter on the command line to reboot. Here's how to do that.

ansible-playbook -e 'reboot=True' -i inventory change_hostname.yaml

Finally, if all goes well the last step is a vaildation routine that makes sure your remote clients hostname matches your inventory_hostname you defined in your inventory. You might need to blow away the tmp/ansible-facts cache dir for this to succeed, however.