Procedure to change master node hetzner type?

[4FunAndProfit]

Hello!

I was wondering what the recommended way is to migrate master nodes to a different Hetzner server type.
Are there any precautions or best practices to follow before doing so?

Thanks a lot for this great tool!

[vitobotta]

Hi, can you tell me about your cluster? What is the current config and what is the latest version of the tool you have used with it?

[4FunAndProfit]

Hi @vitobotta , thanks for your answer!

Latest version of tool i have used : v2.4.2

But my cluster has only one master node, I don't really see how to properly switch server types on the master side

That's why I took the liberty of asking the question in the Q&A (i saw some other people had the same question [ex https://github.com//discussions/504]

On my staging environments, I don't have three master nodes for cost reasons, and I think it would be easier in other cases because we could just go to three, drain + delete one, and recreate.
But on the staging environment with a single node, I'm lost

[vitobotta]

It's doable, provided you are very careful, so take this as a disclaimer :)

You are on the right track, and the procedure is quite simple:

1. Convert the cluster from single master to multi master, by specifying the new instance type for the masters node pool in the configuration file.
2. Once the cluster is up and running and you are absolutely sure everything is working, including being able to connect to and use the cluster from master2 and master2,
3. Drain master1, delete it both with kubectl and from the Hetzner console
4. Re-run the create command with hetzner-k3s to recreate the first master with the new instance type
5. Verify that everything works well and you can use the cluster from master1
6. Drain and delete both master2 and master3 if you want to remain with a single master

This will work just fine if you are careful, and provided your master1 doesn't have the instance type in the node name, so please double check that. If you have created your cluster not long ago with a recent enough version of hetzner-k3s, or have done a proper migration of an older cluster from v1 to v2, you should be fine.

But if your master has the instance type in the node name, then you need to first follow the migration guide from v1 to v2 which you can find in the docs, to remove the instance type from the node name. After that, you can proceed with the above steps.

[4FunAndProfit]

@vitobotta thanks thanks thanks a lot!!

[vitobotta]

No worries :)