README.md

Step 0

Install a cluster

There are three kind of clusters.

• One is using (coreOS and vagrant recipe). The problem is with new versions of coreOS there are some problems because the recipe is no more maintained by CoreOS.

• Now CoreOS encourages use Tectonic as installer and tool to run Kubernetes. There are a free version for less than 10 nodes clusters.

• Last one and recommended is use kubeadm, vagrant and Ubuntu as OS.

Check some default components in a bare cluster

• Display the nodes

kubectl get node
kubectl get cs

• Get components from kubernetes

kubectl get pod -n kube-system

Install a self contained registry

We use registry.yaml inside cluster folder to run the registry. Inside there is a deployment with one replica that define the actual registry container. Also, there is a service to make it available along the cluster. Finally, a daemonset is deployed too for setting a registry proxy so every node can pull from it.

$ kubectl apply -f registry.yaml

Now we need to expose the registry outside the VMs in order to push the images we generate in our host.

$ export REGISTRY_POD=$(kubectl get pods --namespace kube-system -l k8s-app=kube-registry-upstream \
    -o template --template '{{range .items}}{{.metadata.name}} {{.status.phase}}{{"\n"}}{{end}}' \
    | grep Running | head -1 | cut -f1 -d' ')

Thanks to port-forward command we expose the registry in the port 5000.

$ kubectl port-forward --namespace kube-system $REGISTRY_POD 5000:5000 > /dev/null 2>&1 &

Finally, you need to add docker.for.mac.localhost:5000 (localhost in linux) in the insecure registry list so docker daemon will know were the registry.

Let's push a iamge to the registry to verify everything works as expected.

$ docker pull busybox
$ docker tag busybox docker.for.mac.localhost:5000/busybox:latest
$ docker push docker.for.mac.localhost:5000/busybox:latest

Note: If you are running on Linux, replace docker.for.mac.localhost for localhost. Docker in mac runs in a VM and expose it via DNS.

For Linux, it should work out of the box.

Open an issue in case something fails for you.

Install helm

Use helm to install apps or tools in kubernetes cluster is a good idea. They are created by the community with the best practices agreed by different contributors. Further, helm help to mantain version, run releases and rollbacks, and use a central repository to save these receipts.

To install helm please follow the official instructions

Since RBAC is enabled by default in new kubernetes versions we need to run helm with permissions. Helm offers a client for run the actions and a server running as pod to interpret the commands. The server is called Tiller and needs to run a service account with the right permissions.

$ kubectl -n kube-system create sa tiller
$ kubectl create clusterrolebinding tiller --clusterrole cluster-admin --serviceaccount=kube-system:tiller
$ helm init --service-account tiller

Helm client uses kubeconfig for connecting with kubernetes.