How to change IP addressing in a cluster if the platform has been migrated to a VM

Question

How do I change the IP addressing of a VMmanager cluster when the platform has been migrated to a virtual machine (VM)?

Answer

Preparing the master VM for migration

Connect to the platform VM (master VM) via SSH, VNC, or SPICE.

Enable the serial terminal services:

sudo systemctl enable --now serial-getty@ttyS0.service
exit

Verifying access to the master VM via a cluster node

Connect to the cluster node hosting the master VM via SSH. For more information about connecting via SSH, see Workstation setup.
Check that the master VM is present on the node:
```
sudo virsh list
```
Ensure platform-master appears in the list.
Verify you can log in to the VM:
1. Connect to the VM:
```
sudo virsh console <master_vm_name>
```
2. Press Enter.
3. Enter the credentials:
  - username: root;
  - password: root user's password.
4. Check that the command line is accessible after authentication – this confirms the connection is established.
5. Exit the session:
```
exit
```

Changing IP addresses on cluster nodes

Note

If your workstation is in a different subnet, connect to the nodes via the BMC console.

Determine the network management mechanism:
```
cat /etc/network/interfaces
```
If the lines are commented out, NetworkManager is in use.
View current IP bindings:
```
ip addr show | grep $(hostname -I)
```
Change the IP addresses on the node connection interface (default is vmbr0). If using NetworkManager, use the graphical utility: nmtui.
Reboot the cluster nodes to apply the settings:
```
systemctl reboot
```

Changing the IP address on the master VM

Important

Changing the master VM's IP address by any method other than the one described below may render the platform inoperable. If you change the master VM's IP address using standard OS tools, the platform web interface will become unavailable, and SSH connections to the master VM will fail.

Before following these instructions, create a platform backup. For more details, see Creating platform backups.

Connect to the cluster node hosting the master VM via SSH. For more information about connecting via SSH, see Workstation setup.
Verify the master VM is present on the node:
```
sudo virsh list
```
Ensure platform-master appears in the list.
Connect to the VM:
```
sudo virsh console <master_vm_name>
```
Press Enter.
Enter the credentials:
- username: root;
- password: root user's password.
If your hardware uses the 172.17.0.0/16 network, follow the instructions in the article How to change the network used by Docker. Otherwise, skip this step.
Open the network configuration file:
```
sudo nano /etc/network/interfaces
```
Change the guest OS IP address of the master VM.
Save the file and close the editor.
Reboot the master VM:
```
sudo reboot
```

Updating node connection settings in the platform interface

Open the platform web interface using the new IP address of the master VM.
Log in using one of the following methods:
- email and password;
- SSH key. For more details, see the article How to sign in to the platform with a key.
Go to the Nodes section → select a node → menu.
For each node:
1. Click Restore connection.
2. Specify the new IP address.
3. Click the Connect to node button.
Navigate to the task list.
Sort tasks by creation date or by descending ID.
Verify that the tasks Update TLS certificates on node <task_name> have completed successfully. For more information on the task list, see the article Tasks list.

Changing the master VM IP address in the platform

Go to the Networks section.
In the IP pools tab, do one of the following:
- create a new pool containing the master VM's IP address;
- Add the new IP to an existing pool.
  
  Note
  The IP address must match the one specified in /etc/network/interfaces. For more details, see the article Pools management.
In the right menu, click the icon Settings → VM with Platform.
Click Change IP address.
Specify the new IP address of the master VM.
Navigate to the task list.
Sort tasks by creation date or by descending ID.
Verify that the Change IP address tasks have completed successfully. For more information on the task list, see the article Tasks list.

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