From e6adaff217f3848416a8c15fae3b0e50b44e5925 Mon Sep 17 00:00:00 2001
From: Konrad Bucheli <konrad.bucheli@psi.ch>
Date: Wed, 28 Aug 2024 10:02:38 +0200
Subject: [PATCH] document hostname change

---
 _toc.yml                                 |  5 ++-
 admin-guide/configuration/host_rename.md | 50 ++++++++++++++++++++++++
 2 files changed, 53 insertions(+), 2 deletions(-)
 create mode 100644 admin-guide/configuration/host_rename.md

diff --git a/_toc.yml b/_toc.yml
index 9423bc3a..c4ba552d 100644
--- a/_toc.yml
+++ b/_toc.yml
@@ -45,7 +45,7 @@ chapters:
           - file: admin-guide/deployment/re_installation
           - file: admin-guide/deployment/console_installation
           - file: admin-guide/deployment/dmz_installation
-          
+
       - file: admin-guide/configuration
         sections:
           - file: admin-guide/configuration/icinga2
@@ -59,6 +59,7 @@ chapters:
           - file: admin-guide/configuration/resize_vm_disk
           - file: admin-guide/configuration/partitioning
           - file: admin-guide/configuration/networking
+          - file: admin-guide/configuration/host_rename
           - file: admin-guide/configuration/xrdp
           - file: admin-guide/configuration/puppet_agent
           - file: admin-guide/configuration/sudo
@@ -109,7 +110,7 @@ chapters:
           - file: admin-guide/puppet/puppet_client
           - file: admin-guide/puppet/puppet_environments
           - file: admin-guide/puppet/hiera
-  
+
   - file: engineering-guide/index
     sections:
       - file: engineering-guide/infrastructure_systems
diff --git a/admin-guide/configuration/host_rename.md b/admin-guide/configuration/host_rename.md
new file mode 100644
index 00000000..70da45fe
--- /dev/null
+++ b/admin-guide/configuration/host_rename.md
@@ -0,0 +1,50 @@
+# Host Renaming
+
+Following steps are required to rename a host.
+
+
+## Introduce New Hostname
+
+### Sysdb/bob
+For sysdb create a new node with bob as usual.
+For reference do
+
+```
+bob node list -v $OLD_FQDN
+```
+then add the new node
+```
+bob node add $NEW_FQDN $SYSDB_ENV
+bod node set-attr $NEW_FQDN [all attributes as listed above]
+```
+and the same for the MAC addresses:
+```
+for mac in $(bob node list-macs $OLD_FQDN); do echo bob node add-mac $NEW_FQDN $mac; done
+```
+
+### Hiera
+
+In Hiera ensure that a host specific configuration file exists for the FQDN with the same content as for the old hostname.
+
+## Acutal Hostname Change
+
+On the node as `root` run
+
+```
+hostnamectl set-hostname $NEW_FQDN
+rm -rf /etc/puppetlabs/puppet/ssl
+puppet agent -t
+```
+
+which changes the local hostname, removes the local Puppet certificate and updates the configuration with Puppet using the new hostname.
+
+## Other Changes to Consider
+
+- change DNS entry if a static IP address is assigned
+- redo SSL/TLS certificates with new hostname
+
+## Remove Old Hostname
+
+- `bob node delete $OLD_FQDN`
+- remove from Hiera
+- inform the Linux Team (linux-eng@psi.ch) so it can remove from Puppet server the certificate and other data and remove the computer object from the AD