Joining an existing kubernetes cluster

[sayak]

I have been considering using TrueNAS for my home server setup and was looking into using scale instead of core. This is because I already have a kubernetes cluster at home and k8s being a feature in scale made it more attractive to me. But looking at the documentation, it seems like TrueNAS scale spins up its own k8s cluster (single node for now). Since, I have an existing k8s cluster, I was wondering if scale allows us to join to an existing cluster instead of starting a new one.

 

[morganL]

I have been considering using TrueNAS for my home server setup and was looking into using scale instead of core. This is because I already have a kubernetes cluster at home and k8s being a feature in scale made it more attractive to me. But looking at the documentation, it seems like TrueNAS scale spins up its own k8s cluster (single node for now). Since, I have an existing k8s cluster, I was wondering if scale allows us to join to an existing cluster instead of starting a new one.

No it does not.
Kubernetes is not clustered in this first angelfish release
Kubernetes will be clustered in Bluefin release
However, we can only recommend homogeneous clusters managed by the same system.

Your separate Kubernetes node/cluster can use the CSI driver to get its storage volumes from TrueNAS.

 

[sayak]

So, if I understand it right, even in the bluefish release, I won't be able to join a node running Scale to an existing cluster. Scale will always spin up a new cluster in bluefish and we will be able to join nodes to it. In short, scale will deploy its own control plane always and there is no option to join to an external control plane?

 

[morganL]

So, if I understand it right, even in the bluefish release, I won't be able to join a node running Scale to an existing cluster. Scale will always spin up a new cluster in bluefish and we will be able to join nodes to it. In short, scale will deploy its own control plane always and there is no option to join to an external control plane?

I used the word "recommend"..... lots of things are possible, but aren't as reliable.
How does the cluster get its Kubernetes stack software updated?

 

[sayak]

The way I was imagining it to be would be that Scale would only deploy a kubelet which would be able to join an existing control plane. Thus as far as Scale would have been concerned, it would only need to manage the kubelet deployment and not the control plane. Note that this was my speculation before starting this thread.

 

[morganL]

The way I was imagining it to be would be that Scale would only deploy a kubelet which would be able to join an existing control plane. Thus as far as Scale would have been concerned, it would only need to manage the kubelet deployment and not the control plane. Note that this was my speculation before starting this thread.

But you then have to deal with how the data is stored across the cluster.. so that any node can fail.

1st step is getting clustered kubernetes going with scale-out storage and snapshots... still some work to do to make that available and reliable.

 

[sayak]

But you then have to deal with how the data is stored across the cluster.. so that any node can fail.

Yeah, I can see now how that can be a pain to handle. Anyway, thanks for taking the time to clarify these things. Much appreciate it and hopefully I can contribute back to the development of Scale.