How to
This page contains the procedure to rename a host. It hasn't been tested very much, so proceed with caution.
Remove host from Puppet
Start by stopping the puppet-run timer and disabling Puppet on the machine:
systemctl stop puppet.timer && \
puppet agent --disable "renaming in progress"
Then, in tor-puppet, remove references to the host. At the very least the
node's classification yaml should be removed from
tor-puppet-hiera-enc.git/nodes.
Revoke its certificates from the Puppet server using the retirement script:
fab -H foo.torproject.org retire.revoke-puppet
Change the hostname
On the host being renamed, change the hostname:
hostnamectl set-hostname bar.torproject.org && \
sed -i 's/foo/bar/g' /etc/hosts
Then adjust the SSH host keys. Generating new keys isn't mandatory:
sed -i 's/foo/bar/' /etc/ssh/ssh_host_*.pub
We also need to fix the thishost symlink in ud-ldap data:
ud-replicate
cd /var/lib/misc && ln -sf bar.torproject.org thishost
rm -rf foo.torproject.org
Rename the machine in the infrastructure
Ganeti
ganeti-instance rename foo.torproject.org bar.torproject.org
LDAP
Run a search/replace with the old and new hostname in the host's stanza.
Mandos
We need to let the mandos server know about the new hostname:
sed -i 's/foo/bar/' /etc/mandos/clients.conf && \
systemctl restart mandos.service
DNS
Both forward and reverse DNS should be adjusted to use the new hostname.
DNSWL
External hoster platform
If the host is a machine host at Hetzner or another provider, the name should be changed there as well.
Re-bootstrap Puppet
Now the host is ready to be added back to Puppet. A new certificate will be generated in this step. This should be ran from your computer, in Fabric:
fab -H bar.torproject.org puppet.enable
fab -H bar.torproject.org puppet.bootstrap-client
Schedule backups removal
This will schedule the removal of backups under the old hostname:
fab -H foo.torproject.org retire.remove-backups
Adjust documentation
Adjust documentation that may refer to the old hostname, including the tor-passwords, the wiki and the Tor "VM Hosts" spreadsheet.