Thanks Jeff!
Everything I know about Kubernetes I learned from a cluster of Raspberry Pis
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Re: Everything I know about Kubernetes I learned from a cluster of Raspberry Pis
#12I LOVE Jeff's work and I own his Ansible book. The setup is pretty awesome. FWIW I think you could do this with local VMs a little more easily and provision with Vagrant. Having said that, a cluster of Pis is super fun!
What do you know, that's exactly how I do local development work for the cluster ;) https://github.com/geerlingguy/raspberry-pi-dramble/tree/mas...
Re: Everything I know about Kubernetes I learned from a cluster of Raspberry Pis
#13Thankfully these days, places like Digital Ocean and Linode have managed K8s where you only pay for the compute nodes, for $5/month each. So it's fairly cheap and easy to learn on a "real" cluster without having to build one.
Building a cluster is a fun and relatively easy project. You learn much more by having the hardware at your fingertips. You can simulate network failures and power failures or you can crash an important daemon. By causing problems you can see how K8s responds and manages itself when it does not have the nodes it expects. It is important to know these things because, for example, if you create a pod instead of a replica set then the loss of a node will mean the inability to use the pod assigned to that node. You need to know how a pod and a replica set differ in order to create a self-healing stack. You can learn all of that with the cloud solutions but the ability to answer your own questions will always be the superior means of learning.
The Agile movement has convinced many that the solution that gets you up and running today is the best. A good engineer is not afraid of working and learning instead of just buying a pre-baked implementation and calling themself an experienced user. The cluster that I know like the back of my hand is my “real” cluster. The production cluster is someone else’s that I just rent.
Re: Everything I know about Kubernetes I learned from a cluster of Raspberry Pis
#14A good method for learning how clusters work and playing with them without having to spend a lot of time re-building when you break things is kind ( https://kind.sigs.k8s.io/ ). Each node is a Docker container, but the version of Kubernetes running inside it is vanilla Kubeadm, so it's quite representative of what "real" clusters would look like. The great thing about it is you can spin up a cluster in < 2 mins local…
I use Kind (and Minikube, and a number of other solutions too), but this is kind of my "Kubernetes-the-really-hard-way" fun project.
Note that I maintain a parallel configuration that runs a multi-node cluster on Vagrant for local development [1] as well as a docker environment built for CI purposes[2] using almost all the same images, with the same Ansible playbooks to configure them all across platforms.
[1] https://github.com/geerlingguy/raspberry-pi-dramble/tree/mas...
[2] https://github.com/geerlingguy/raspberry-pi-dramble/tree/mas...
Re: Everything I know about Kubernetes I learned from a cluster of Raspberry Pis
#15Thankfully these days, places like Digital Ocean and Linode have managed K8s where you only pay for the compute nodes, for $5/month each. So it's fairly cheap and easy to learn on a "real" cluster without having to build one.
Building a cluster is a fun and relatively easy project. You learn much more by having the hardware at your fingertips. You can simulate network failures and power failures or you can crash an important daemon. By causing problems you can see how K8s responds and manages itself when it does not have the nodes it expects. It is important to know these things because, for example, if you create a pod instead of a repli…
Through my work on this project, I've learned a ton about kubectl, kubeadm, the control plane, etc. that I never learned when managing EKS clusters at a previous job. It's good to know more of the 'guts' of an insanely complex ecosystem like Kubernetes, which is why I often recommend people follow Kelsey Hightower's "Kubernetes the Hard Way" guide to install Kubernetes from primitives at least once.
Re: Everything I know about Kubernetes I learned from a cluster of Raspberry Pis
#16Thankfully these days, places like Digital Ocean and Linode have managed K8s where you only pay for the compute nodes, for $5/month each. So it's fairly cheap and easy to learn on a "real" cluster without having to build one.
Building a cluster is a fun and relatively easy project. You learn much more by having the hardware at your fingertips. You can simulate network failures and power failures or you can crash an important daemon. By causing problems you can see how K8s responds and manages itself when it does not have the nodes it expects. It is important to know these things because, for example, if you create a pod instead of a repli…
Sure. It's not necessarily skipping all those things you mention that's the motivation. Just the desired order and upfront effort to learn things about K8S.
Re: Everything I know about Kubernetes I learned from a cluster of Raspberry Pis
#173 years ago, I also wanted a bare metal cluster for my homelab. I wanted x86-64, low power consumption, small footprint, and low cost. I ended up building this 5 node nano ITX tower:
https://vyshane.com/2016/12/19/5-node-nano-itx-kubernetes-to...
I think that the exposed boards adds to its charm. Doesn't help with dust though.
Re: Everything I know about Kubernetes I learned from a cluster of Raspberry Pis
#18A good method for learning how clusters work and playing with them without having to spend a lot of time re-building when you break things is kind ( https://kind.sigs.k8s.io/ ). Each node is a Docker container, but the version of Kubernetes running inside it is vanilla Kubeadm, so it's quite representative of what "real" clusters would look like. The great thing about it is you can spin up a cluster in < 2 mins local…
How does this compare to k3s? https://rancher.com/docs/k3s/latest/en/
k3s is usually (AFAIK) run on VMs for production purposes, rather than being used for testing, which is where kind shines.
The major advantage of kind is you download a single binary, run one command and quickly have a functional, disposable cluster, anywhere that Docker runs.
Re: Everything I know about Kubernetes I learned from a cluster of Raspberry Pis
#19I learned k8s with some NUCs we had laying around at work. Might be easier than Pi, but not as cheap. Some things I used: https://metallb.universe.tf/ (LoadBalancer) https://cilium.io/ (Networking) https://rook.io/ (Persistent Storage)
I also use MetalLB and Rook. Can't say enough good things about them.
I have also used Kube-Router (https://kube-router.io - Digital Ocean's non Virtual networking plugin for bare metal environments; it puts your containers on your physical network, which is freaking neat) and loved that, but since I started deploying kubernetes with Rancher I've found for dev clusters I'm not caring about what networking is used. (currently running Canal).
Not sure what we will decide on when we go to production.
Re: Everything I know about Kubernetes I learned from a cluster of Raspberry Pis
#20A good method for learning how clusters work and playing with them without having to spend a lot of time re-building when you break things is kind ( https://kind.sigs.k8s.io/ ). Each node is a Docker container, but the version of Kubernetes running inside it is vanilla Kubeadm, so it's quite representative of what "real" clusters would look like. The great thing about it is you can spin up a cluster in < 2 mins local…
I use Kind (and Minikube, and a number of other solutions too), but this is kind of my "Kubernetes-the-really-hard-way" fun project. Note that I maintain a parallel configuration that runs a multi-node cluster on Vagrant for local development [1] as well as a docker environment built for CI purposes[2] using almost all the same images, with the same Ansible playbooks to configure them all across platforms. [1] https:…
yeah I think this approach will have fewer limitations than kind, and also it's fun to try different approaches!
BTW I think your ansible book is great, really helped me get to grips with it.