Remove a machine

Before you start, make sure that the machines you are removing are no longer needed for anything.

1. Remove the node from the puppetmaster

You need to remove the nodes from the puppetmaster in each environment. This is needed to clean up exported resources from Puppet, including removing checks from Icinga.

First, disable Puppet on the machines you wish to remove.

Next, SSH into the puppetmaster for the environment:

$ ssh puppetmaster-1.management.production

for Carrenza, or

$ govukcli set-context integration
$ govukcli ssh puppetmaster

for AWS.

Then run this on each machine:

$ govuk_node_clean <machine_name>

Where <machine_name> might be machine-name-1.vdc-name.production (Carrenza) or ip-a-b-c-d.eu-west-1.compute.internal (AWS). To find the names of the machines, you can list the nodes on puppetmaster:

$ sudo puppet cert list --all

If govuk_node_clean was successful, you will get output like:

Submitted 'deactivate node' for redirector-1.redirector.production with UUID 0fb445ff-d660-41eb-b6d2-eca40447d4bf
Notice: Revoked certificate with serial 127
Notice: Removing file Puppet::SSL::Certificate redirector-1.redirector.production at '/etc/puppet/ssl/ca/signed/redirector-1.redirector.production.pem'

After this, Icinga will forget about the machine when it next runs Puppet. You can force this with:

$ ssh monitoring-1.management.production
$ govuk_puppet --test

You may need to wait a few minutes, but it should then disappear from the “Host Detail” page in Icinga.

2. Remove from puppet

If you are removing a class of machines, you will need to remove the definitions from Puppet.

Carrenza

3. Remove from vCloud Director

Sign in to the vCloud Director instance for the given environment. Go to ‘My Cloud’, search for the given machine, stop it, and then delete it.

4. Remove from govuk-provisioning

If your machine class matches a vDC, be careful not to remove firewall rules that apply to the vDC.

AWS

3. Remove from Terraform

If you’re removing a class of machines, first deploy Terraform for the relevant project using the destroy action. This will remove all the EC2 instances.

Then, remove the project itself from govuk-aws.

If you’re removing a single machine, change the asg_size for the relevant project in govuk-aws-data (example) and deploy Terraform.