update exist cluster

[ozbillwang]

What would you like to be added:

after I create a cluster by kind, I'd like to add one more worker node or master node. but I can't find the option/command to update exist cluster.

change from

kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
nodes:
- role: control-plane
- role: worker
- role: worker

to

kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
nodes:
- role: control-plane
- role: worker
- role: worker
- role: worker

If I run create command, I will get error

$ kind create cluster --config kind-config-1.yaml
ERROR: node(s) already exist for a cluster with the name "kind"

So how to update exist cluster, such as adding new worker node, change node images/kubernetes version, etc.

Why is this needed:
after I create a cluster by kind, I'd like to add one more worker node or master node. but I can't find the option/command to update exist cluster.

Currently I have to delete and create a new cluster with new configuration

So if we can have an new command update or apply to deal with this request

kind update cluster --config kind-config-1.yaml

or

kind apply cluster --force --config kind-config-1.yaml

[ozbillwang]

Second, after I restart my laptop, I found the kind kubernetes cluster doesn't start up automatically.

Now there is no way I can start them again.

$ kind get nodes
kind-worker
kind-worker2
kind-control-plane

$ kind get clusters
kind

$ docker ps
CONTAINER ID        IMAGE               COMMAND             CREATED             STATUS              PORTS               NAMES

$ kubectl get clusters kind
The connection to the server 127.0.0.1:32774 was refused - did you specify the right host or port?

any hints?

[BenTheElder]

This is a fairly complicated feature that we currently have no intention of developing. It's not necessary for most testing purposes.

For rebooting there is an existing issue in the tracker that I am again working on.

[marlon-sousa]

Hello,

I have a slightly different question:

I have a KIND cluster and now I developed a new service. This service uses a node port, but this node port is not yet mapped to a host port in the configuration file, because the service has just been developed.
Is there any way in which I could reapply the custom config file to restart the cluster, but now taking in consideration the new port mapping?

If so, I would like to know, because destroying a cluster and them starting a new one with all the deployments involved is very expensive in terms of time.

Thanks,
Marlon

[BenTheElder]

Hi, it is possible, though not via kind itself or the config, but best discussed in another issue. See e.g. #702 (comment)

Also, if you're on linux you can skip port mapping entirely, but on mac see the discussion there, and the notes in https://kind.sigs.k8s.io/docs/user/loadbalancer/

This particular issue though is one of the reason we don't support reconfiguring, as docker just doesn't support adding port mapping to a container dynamically, you have to re-create anyhow.

If you'd like to discuss further, please file a new support issue, that way we can keep track of it better (e.g. most people are not tracking old closed issues) and help make it more searchable for the next person, thanks!