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

Two places to edit —— 拓扑（名称、IP、磁盘、网卡）进 inventory，真实 MAC 进那个 不进版本控制的 secrets 文件（公开仓库里不要出现真实 MAC，#550）：

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: "{{ metal_macs['metal3'] }}", disk: sda, network_interface: eno1}
+        metal4: {ansible_host: 192.168.1.114, mac: "{{ metal_macs['metal4'] }}", disk: sda, network_interface: eno1}

metal/inventories/group_vars/all/zz-secrets.yml

diff --git a/metal/inventories/group_vars/all/zz-secrets.yml b/metal/inventories/group_vars/all/zz-secrets.yml
--- a/metal/inventories/group_vars/all/zz-secrets.yml
+++ b/metal/inventories/group_vars/all/zz-secrets.yml
@@ -1,3 +1,4 @@
 metal_macs:
   metal3: "aa:bb:cc:00:00:03"
+  metal4: "aa:bb:cc:00:00:04"

这个文件被 gitignore，MAC 放哪里、真实值怎么取见 metal/README.md。

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: "{{ metal_macs['metal0'] }}", disk: sda, network_interface: eno1}
         metal1: {ansible_host: 192.168.1.111, mac: "{{ metal_macs['metal1'] }}", disk: sda, network_interface: eno1}
-        metal2: {ansible_host: 192.168.1.112, mac: "{{ metal_macs['metal2'] }}", disk: sda, network_interface: eno1}
     workers:
       hosts:
         metal3: {ansible_host: 192.168.1.113, mac: "{{ metal_macs['metal3'] }}", disk: sda, network_interface: eno1}

（它在 zz-secrets.yml 的 metal_macs 里的条目可以顺手删掉，留着不影响运行。）

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 root@${NODE_IP} poweroff