VMware vctl KinD - Writing configuration failed

Robert Guske included in Platforms End User Computing

2021-03-02 1486 words 7 minutes

Contents

Introduction

Quote

“Everything fails all the time”

– Werner Vogels, Amazon CTO

^^But why always at the most inappropriate moments?! Just recently it happened to me, that one day before I needed my homelab for a presentation, the vSAN caching disk failed and had to be replaced.

Nooooooooooo 😩👹 pic.twitter.com/GHELTrPeTn
— Robert Guske (@RobertGuske) February 23, 2021

Normally there is no real issue with loosing a caching device in a vSAN cluster but let me put it that way, I’m really using all my given 2-node cluster resources and a potential risk of data-loss was calculated. Not everybody can have a “homelab” like the Homelab King¹, right? 😉

Unfortunately, some of my Tanzu Kubernetes Grid clusters² suffered from the outage and was the one providing my Harbor³ registry service which I needed for my demo.

However, there are other ways to help yourself when your homelab is in “maintenance” and I wanted to leverage VMware Fusion vctl⁴ to quickly instantiate a KinD⁵ cluster locally on my machine, to install Harbor via a Helm chart⁶ afterwards on it. For the purposes of my presentation this would have been totally sufficient. But then it turned out that I have to find an alternative again 🤦.

Adjusting the CRX VM with appropriate resources

By default vctl assigns 2 GB of memory and 2 CPU cores for the CRX VM that hosts the Kubernetes node container. For my Harbor 1-node deployment I sticked to the minimum requirements⁷ (2 CPUs, 4 GB Mem) for the Kubernetes node but also decided to give the CRX VM a little bit more, to keep the option open to run a Multo-Node deployment as well. Therefore, I applied the following configuration:

vctl system config --vm-cpus 4 --vm-mem 8192 --k8s-cpus 2 --k8s-mem 4096 which will adjust the config.yaml in ~/.vctl/ accordingly.

        
        
        
    
cache-location: /Users/rguske/.vctl
k8s-cpus: 2
k8s-mem: 4096
log-level: info
log-location: /Users/rguske/.vctl/containerd.log
mount-name: Fusion Container Storage
pid: 45414
storage: 128g
vm-cpus: 4
vm-mem: 8192
vmnet: vmnet8

KinD - Writing configuration failed

Moving forward to the KinD cluster creation itself. I first looked up for the latest kindest/node image version I can choose.

/img/posts/202102_vctlkindissue/CapturFiles-20210227_035317.jpg — Figure I: kindest/node available images

You can see at Figure I that v1.19.7 is at the top (sort by: Newest) and so my choice was taken.

kind create cluster --image kindest/node:v1.19.7 --name harbor

        
        
        
    
Creating cluster "harbor" ...
 ✓ Ensuring node image (kindest/node:v1.19.7) 🖼
 ✓ Preparing nodes 📦
 ✗ Writing configuration 📜
ERROR: failed to create cluster: failed to generate kubeadm config content: failed to get kubernetes version from node: failed to get file: command "docker exec --privileged harbor-control-plane cat /kind/version" failed with error: exit status 1
Command Output: level=error msg="Error starting process: container = harbor-control-plane, command = [cat /kind/version] env = [PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin TERM=xterm PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin container=docker TERM=xterm] error = container_linux.go:345: starting container process caused \"read init-p: connection reset by peer\": unknown"

What is this error msg telling us? Let’s activate debug mode by adding option -v 1 to the command.

kind create cluster --image kindest/node:v1.19.7 --name harbor -v 1

        
        
        
    
Creating cluster "harbor" ...
DEBUG: docker/images.go:58] Image: kindest/node:v1.19.7 present locally
 ✓ Ensuring node image (kindest/node:v1.19.7) 🖼
 ✓ Preparing nodes 📦
 ✗ Writing configuration 📜
ERROR: failed to create cluster: failed to generate kubeadm config content: failed to get kubernetes version from node: failed to get file: command "docker exec --privileged harbor-control-plane cat /kind/version" failed with error: exit status 1
Command Output: level=error msg="Error starting process: container = harbor-control-plane, command = [cat /kind/version] env = [PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin TERM=xterm PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin container=docker TERM=xterm] error = container_linux.go:345: starting container process caused \"read init-p: connection reset by peer\": unknown"
Stack Trace:
sigs.k8s.io/kind/pkg/errors.WithStack
        sigs.k8s.io/kind/pkg/errors/errors.go:51
sigs.k8s.io/kind/pkg/exec.(*LocalCmd).Run
        sigs.k8s.io/kind/pkg/exec/local.go:124
sigs.k8s.io/kind/pkg/cluster/internal/providers/docker.(*nodeCmd).Run
        sigs.k8s.io/kind/pkg/cluster/internal/providers/docker/node.go:146
sigs.k8s.io/kind/pkg/exec.CombinedOutputLines
        sigs.k8s.io/kind/pkg/exec/helpers.go:67
sigs.k8s.io/kind/pkg/cluster/nodeutils.KubeVersion
        sigs.k8s.io/kind/pkg/cluster/nodeutils/util.go:35
sigs.k8s.io/kind/pkg/cluster/internal/create/actions/config.getKubeadmConfig
        sigs.k8s.io/kind/pkg/cluster/internal/create/actions/config/config.go:170
sigs.k8s.io/kind/pkg/cluster/internal/create/actions/config.(*Action).Execute.func1.1
        sigs.k8s.io/kind/pkg/cluster/internal/create/actions/config/config.go:82
sigs.k8s.io/kind/pkg/errors.UntilErrorConcurrent.func1
        sigs.k8s.io/kind/pkg/errors/concurrent.go:30
runtime.goexit
        runtime/asm_amd64.s:1374

I have to admit that I couldn’t really use the output for further debugging and also searching the web helped me neither. Consequently, I reached out internally and got the hint that v1.20.0 should work.

v1.20.0 ❓ ❗ I haven’t seen this version on the list of available images (Figure I) and so I went back to Docker Hub and searched for this particular version.

Okay, it exists and besides it a v1.20.2. as well. I learned Newest isn’t related to Tags, what IMO would make sense, but it’s related to last pushed.

/img/posts/202102_vctlkindissue/Screenshot2021-03-01.jpg — Figure II: hidden kindest image version 1.20.0

Give it a another try and this time with v1.20.0.

kind create cluster --image kindest/node:v1.20.0 --name harbor

        
        
        
    
Creating cluster "harbor" ...
 ✓ Ensuring node image (kindest/node:v1.20.0) 🖼
 ✓ Preparing nodes 📦
 ✓ Writing configuration 📜
 ✓ Starting control-plane 🕹️
 ✓ Installing CNI 🔌
 ✓ Installing StorageClass 💾
Set kubectl context to "kind-harbor"
You can now use your cluster with:

kubectl cluster-info --context kind-harbor

Not sure what to do next? 😅  Check out https://kind.sigs.k8s.io/docs/user/quick-start/

        
kubectl get nodes -o wide
NAME                   STATUS   ROLES                  AGE   VERSION   INTERNAL-IP    EXTERNAL-IP   OS-IMAGE                                     KERNEL-VERSION       CONTAINER-RUNTIME
harbor-control-plane   Ready    control-plane,master   48s   v1.20.0   192.168.43.2   <none>        Ubuntu Groovy Gorilla (development branch)   4.19.138-7.ph3-esx   containerd://1.4.0

Created. On the one hand that’s a satisfying result but on the other hand of course not, because we want to have the flexibilty to create a KinD cluster with every available Kubernetes (kindest/node) version.

If prior 1.20.0 won’t work, will the next above work?

kind create cluster --image kindest/node:v1.20.2 --name harbor

        
        
        
    
Creating cluster "harbor" ...
 ✓ Ensuring node image (kindest/node:v1.19.7) 🖼
 ✓ Preparing nodes 📦
 ✗ Writing configuration 📜
ERROR: failed to create cluster: failed to generate kubeadm config content: failed to get kubernetes version from node: failed to get file: command "docker exec --privileged harbor-control-plane cat /kind/version" failed with error: exit status 1
Command Output: level=error msg="Error starting process: container = harbor-control-plane, command = [cat /kind/version] env = [PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin TERM=xterm PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin container=docker TERM=xterm] error = container_linux.go:345: starting container process caused \"read init-p: connection reset by peer\": unknown"

😳 Failed

I repeated it with a couple of other versions and created the following table with my observations:

My Test Results

kindest/node Version	Result
1.20.2	❌
1.20.0	✅
1.19.7	❌
1.19.1	✅
1.18.8	✅

All my tests were made with the following versions:

OS, App, CLI, Runtime	Version
macOS Big Sur	11.2.1 (20D75)
Fusion	12.1.0 (17195230)
vctl	1.1.1
containerd github.com/containerd/containerd	v1.3.2-vmw

Heads up!

No solution yet

I don’t have a solution for this issue yet but I will keep this post updated. For the time being, I recommend using a version which passed my test.

Bonus: Multi-Node deployment

I have mentioned at the beginning, that I have assigned enough resources to the CRX VM to run a multi-node KinD deployment and I’d like to show you now how to instantiate this by using the --config option.

Just create a file in a directory of your choice and add the following description to it:

Example:

vim ~/.kube/kind_worker

        
        
        
    
# two node (one ctrl plane & one worker node) cluster config
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
nodes:
- role: control-plane
- role: worker
- role: worker

kind create cluster --image kindest/node:v1.20.0 --name kind-cluster-harbor --config ~/.kube/kind_worker

        
Creating cluster "kind-cluster-harbor" ...
 ✓ Ensuring node image (kindest/node:v1.20.0) 🖼
 ✗ Preparing nodes 📦 📦 
ERROR: failed to create cluster: docker run error: command "docker run --hostname kind-cluster-harbor-control-plane --name kind-cluster-harbor-control-plane --label io.x-k8s.kind.role=control-plane --privileged --security-opt seccomp=unconfined --security-opt apparmor=unconfined --tmpfs /tmp --tmpfs /run --volume /var --volume /lib/modules:/lib/modules:ro --detach --tty --label io.x-k8s.kind.cluster=kind-cluster-harbor --net kind --restart=on-failure:1 --publish=127.0.0.1:61721:6443/TCP kindest/node:v1.20.0" failed with error: exit status 1
Command Output: level=error msg="failed to create container: container name (kind-cluster-harbor-control-plane) length is greater than the maximum allowed length (30)"

container name length exeeded

Command Output: level=error msg=“failed to create container: container name (kind-cluster-harbor-control-plane) length is greater than the maximum allowed length (30)”

Ooookay 🙄 the given cluster name is too long. Shortened:

kind create cluster --image kindest/node:v1.20.0 --name kind-harbor --config ~/.kube/kind_worker

        
        
        
    
Creating cluster "kind-harbor" ...
 ✓ Ensuring node image (kindest/node:v1.20.0) 🖼
 ✓ Preparing nodes 📦 📦 📦
 ✓ Writing configuration 📜
 ✓ Starting control-plane 🕹️
 ✓ Installing CNI 🔌
 ✓ Installing StorageClass 💾
 ✓ Joining worker nodes 🚜
Set kubectl context to "kind-kind-harbor"
You can now use your cluster with:

kubectl cluster-info --context kind-kind-harbor

Thanks for using kind! 😊

kubectl get nodes -o wide

        
NAME                        STATUS   ROLES                  AGE   VERSION   INTERNAL-IP    EXTERNAL-IP   OS-IMAGE                                     KERNEL-VERSION       CONTAINER-RUNTIME
kind-harbor-control-plane   Ready    control-plane,master   67s   v1.20.0   192.168.43.6   <none>        Ubuntu Groovy Gorilla (development branch)   4.19.138-7.ph3-esx   containerd://1.4.0
kind-harbor-worker          Ready    <none>                 39s   v1.20.0   192.168.43.5   <none>        Ubuntu Groovy Gorilla (development branch)   4.19.138-7.ph3-esx   containerd://1.4.0
kind-harbor-worker2         Ready    <none>                 39s   v1.20.0   192.168.43.7   <none>        Ubuntu Groovy Gorilla (development branch)   4.19.138-7.ph3-esx   containerd://1.4.0

Wohoo, a multi-node Kubernetes cluster running locally on my desktop.

Commands I used

These are the commands I used in this post:

vctl version
vctl system config --vm-cpus 4 --vm-mem 8192 --k8s-cpus 2 --k8s-mem 4096
kind create cluster --image kindest/node:v1.20.0 --name kind-cluster
kind create cluster --image kindest/node:v1.20.0 --name kind-cluster -v 1
vim ~/.kube/kind_worker
kind create cluster --image kindest/node:v1.20.0 --name kind-harbor --config ~/.kube/kind_worker