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Add or remove nodes

Or how to scale vertically. To replace the same node with a clean OS, remove it and add it again.

Add new nodes

Tip

You can add multiple nodes at the same time

Add its details to the inventory at the end of the group (masters or workers):

metal/inventories/prod.yml
diff --git a/metal/inventories/prod.yml b/metal/inventories/prod.yml
index 7f6474a..1bb2cbc 100644
--- a/metal/inventories/prod.yml
+++ b/metal/inventories/prod.yml
@@ -8,3 +8,4 @@ metal:
     workers:
       hosts:
         metal3: {ansible_host: 192.168.1.113, mac: '00:23:24:d1:f5:69', disk: sda, network_interface: eno1}
+        metal4: {ansible_host: 192.168.1.114, mac: '00:11:22:33:44:55', disk: sda, network_interface: eno1}

Install the OS and join the cluster:

make metal

That's it!

Remove a node

Danger

It is recommended to remove nodes one at a time

Remove it from the inventory:

metal/inventories/prod.yml
diff --git a/metal/inventories/prod.yml b/metal/inventories/prod.yml
index 7f6474a..d12b50a 100644
--- a/metal/inventories/prod.yml
+++ b/metal/inventories/prod.yml
@@ -4,7 +4,6 @@ metal:
       hosts:
         metal0: {ansible_host: 192.168.1.110, mac: '00:23:24:d1:f3:f0', disk: sda, network_interface: eno1}
         metal1: {ansible_host: 192.168.1.111, mac: '00:23:24:d1:f4:d6', disk: sda, network_interface: eno1}
-        metal2: {ansible_host: 192.168.1.112, mac: '00:23:24:e7:04:60', disk: sda, network_interface: eno1}
     workers:
       hosts:
         metal3: {ansible_host: 192.168.1.113, mac: '00:23:24:d1:f5:69', disk: sda, network_interface: eno1}

Drain the node:

kubectl drain ${NODE_NAME} --delete-emptydir-data --ignore-daemonsets --force

Remove the node from the cluster

kubectl delete node ${NODE_NAME}

Shutdown the node:

ssh [email protected]${NODE_IP} poweroff