openSUSE Kubernetes Dev With kind
Yesterday I discussed getting openSUSE configured for doing DevOps and Kubernetes work. I ended with settling on kind as my solution for a local Kubernetes cluster. I have done a little research. It seems back in April, and there were some issues around kind and Btrfs, which has been closed with a fix. All that is left now is to create a cluster and deploy something to make sure that it works. Let’s jump in.
Configuring and Exploring the Cluster
The first step is to create our cluster.
$ kind create cluster Creating cluster "kind" ... ✓ Ensuring node image (kindest/node:v1.19.1) 🖼 ✓ Preparing nodes 📦 ✓ Writing configuration 📜 ✓ Starting control-plane 🕹️ ✓ Installing CNI 🔌 ✓ Installing StorageClass 💾 Set kubectl context to "kind-kind" You can now use your cluster with: kubectl cluster-info --context kind-kind Have a question, bug, or feature request? Let us know! https://kind.sigs.k8s.io/#community 🙂
Awesome! It’s up and running and consuming about 500MB of RAM, which isn’t all that intensive. Let’s check out what our system looks like now. Let’s first set our context, so we don’t have to pass it in continually.
$kubectl config set-context kind-kind Context "kind-kind" modified.
Now we can run cluster-info without having to pass the context.
$ kubectl cluster-info Kubernetes master is running at https://127.0.0.1:45145 KubeDNS is running at https://127.0.0.1:45145/api/v1/namespaces/kube-system/services/kube-dns:dns/proxy To further debug and diagnose cluster problems, use 'kubectl cluster-info dump'.
We can also check out what pods we have running on our entire cluster.
$ kubectl get pods -A NAMESPACE NAME READY STATUS RESTARTS AGE kube-system coredns-f9fd979d6-vkkv2 1/1 Running 0 6m25s kube-system coredns-f9fd979d6-zz4lk 1/1 Running 0 6m25s kube-system etcd-kind-control-plane 1/1 Running 0 6m29s kube-system kindnet-dsq6j 1/1 Running 0 6m25s kube-system kube-apiserver-kind-control-plane 1/1 Running 0 6m29s kube-system kube-controller-manager-kind-control-plane 1/1 Running 0 6m29s kube-system kube-proxy-mtmbm 1/1 Running 0 6m25s kube-system kube-scheduler-kind-control-plane 1/1 Running 0 6m29s local-path-storage local-path-provisioner-78776bfc44-56t2c 1/1 Running 0 6m25s
It looks like it’s using CoreDNS along kindnet for CNI and a local file provisioner. Everything else seems fairly typical. This is a pretty nice little setup for doing local development against Kubernetes.
Deploying an App
We have a working cluster at this point, yet the configuration isn’t complete for what we need to do. We will first need to delete the cluster.
$ kind delete cluster
Now create a kind.yaml file that will be the configuration for our cluster and paste what is below there. This will tell kind to map the port 6000 on the host to the ingress controller port.
kind: Cluster apiVersion: kind.x-k8s.io/v1alpha4 nodes: - role: control-plane kubeadmConfigPatches: - | kind: InitConfiguration nodeRegistration: kubeletExtraArgs: node-labels: "ingress-ready=true" extraPortMappings: - containerPort: 80 hostPort: 6000 protocol: TCP
Let’s create a new cluster with the config.
$ kind create cluster --config kind.yaml Creating cluster "kind" ... ✓ Ensuring node image (kindest/node:v1.19.1) 🖼 ✓ Preparing nodes 📦 ✓ Writing configuration 📜 ✓ Starting control-plane 🕹️ ✓ Installing CNI 🔌 ✓ Installing StorageClass 💾 Set kubectl context to "kind-kind" You can now use your cluster with: kubectl cluster-info --context kind-kind Have a nice day! 👋
Now that the cluster is up, we can add our Nginx Ingress controller.
$ kubectl apply -f https://raw.githubusercontent.com/kubernetes/ingress-nginx/master/deploy/static/provider/kind/deploy.yaml
We need to check that our ingress controller is running.
$ kubectl get pod --namespace ingress-nginx NAME READY STATUS RESTARTS AGE ingress-nginx-admission-create-gq5tp 0/1 Completed 0 46s ingress-nginx-admission-patch-g7n4p 0/1 Completed 0 46s ingress-nginx-controller-55dccbb989-jzp6m 1/1 Running 0 46s
It looks like it’s working. We can now deploy an app to test. We will use an echo server to keep it simple. Create hello.yaml with the following code.
kind: Pod apiVersion: v1 metadata: name: hello-app labels: app: hello spec: containers: - name: hello-app image: hashicorp/http-echo:0.2.3 args: - "-text=Hello from a kind cluster." --- kind: Service apiVersion: v1 metadata: name: hello-service spec: selector: app: hello ports: # Default port used by the image - port: 5678 --- apiVersion: networking.k8s.io/v1beta1 kind: Ingress metadata: name: hello-ingress spec: rules: - http: paths: - path: /hello backend: serviceName: hello-service servicePort: 5678
Apply hello.yaml to create our objects.
$ kubectl apply -f hello.yaml pod/hello-app created service/hello-service created ingress.networking.k8s.io/hello-ingress created
All that is left is to call it.
$ curl localhost:6000/hello Hello from a kind cluster.
I hope that you found this useful. One limitation that I am aware of that I wasn’t originally is that these clusters are not persistent. My understanding is that it’s by design for testing Kubernetes. In some ways, this is good as it will require you to push more of your setup into a single manifest to script it out, which is good. It can be frustrating to run through these steps every time.
Thanks for reading,
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