Setup a Kubernetes Cluster

4 minute read

In this module, you set up a Kubernetes cluster that has Istio installed and a namespace to use throughout the tutorial.

Ensure you have access to a Kubernetes cluster. You can use the Google Kubernetes Engine or the IBM Cloud Kubernetes Service.
Create an environment variable to store the name of a namespace that you will use when you run the tutorial commands. You can use any name, for example tutorial.
```
$ export NAMESPACE=tutorial
```
Create the namespace:
```
$ kubectl create namespace $NAMESPACE
```
If you are an instructor, you should allocate a separate namespace per each participant. The tutorial supports work in multiple namespaces simultaneously by multiple participants.
Install Istio using the demo profile.
Next, enable Envoy’s access logging as described in Enable Envoy’s access logging. Skip the clean up and delete steps, because you need the sleep application for later tutorial modules.

Create a Kubernetes Ingress resource for these common Istio services using the kubectl command shown. It is not necessary to be familiar with each of these services at this point in the tutorial.

The kubectl command can accept an in-line configuration to create the Ingress resources for each service:

$ kubectl apply -f - <<EOF
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: istio-system
  namespace: istio-system
spec:
  rules:
  - host: my-istio-dashboard.io
    http:
      paths:
      - path: /*
        backend:
          serviceName: grafana
          servicePort: 3000
  - host: my-istio-tracing.io
    http:
      paths:
      - path: /*
        backend:
          serviceName: tracing
          servicePort: 9411
  - host: my-istio-logs-database.io
    http:
      paths:
      - path: /*
        backend:
          serviceName: prometheus
          servicePort: 9090
  - host: my-kiali.io
    http:
      paths:
      - path: /*
        backend:
          serviceName: kiali
          servicePort: 20001
EOF

Create a role to provide read access to the istio-system namespace. This role is required to limit permissions of the participants in the steps below.

$ kubectl apply -f - <<EOF
kind: Role
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: istio-system-access
  namespace: istio-system
rules:
- apiGroups: ["", "extensions", "apps"]
  resources: ["*"]
  verbs: ["get", "list"]
EOF

Create a service account for each participant:

$ kubectl apply -f - <<EOF
apiVersion: v1
kind: ServiceAccount
metadata:
  name: ${NAMESPACE}-user
  namespace: $NAMESPACE
EOF

Limit each participant’s permissions. During the tutorial, participants only need to create resources in their namespace and to read resources from istio-system namespace. It is a good practice, even if using your own cluster, to avoid interfering with other namespaces in your cluster.

Create a role to allow read-write access to each participant’s namespace. Bind the participant’s service account to this role and to the role for reading resources from istio-system:

$ kubectl apply -f - <<EOF
kind: Role
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: ${NAMESPACE}-access
  namespace: $NAMESPACE
rules:
- apiGroups: ["", "extensions", "apps", "networking.k8s.io", "networking.istio.io", "authentication.istio.io",
              "rbac.istio.io", "config.istio.io"]
  resources: ["*"]
  verbs: ["*"]
---
kind: RoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: ${NAMESPACE}-access
  namespace: $NAMESPACE
subjects:
- kind: ServiceAccount
  name: ${NAMESPACE}-user
  namespace: $NAMESPACE
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: ${NAMESPACE}-access
---
kind: RoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: ${NAMESPACE}-istio-system-access
  namespace: istio-system
subjects:
- kind: ServiceAccount
  name: ${NAMESPACE}-user
  namespace: $NAMESPACE
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: istio-system-access
EOF

Each participant needs to use their own Kubernetes configuration file. This configuration file specifies the cluster details, the service account, the credentials and the namespace of the participant. The kubectl command uses the configuration file to operate on the cluster.

Generate a Kubernetes configuration file for each participant:

$ cat <<EOF > ./${NAMESPACE}-user-config.yaml
apiVersion: v1
kind: Config
preferences: {}

clusters:
- cluster:
    certificate-authority-data: $(kubectl get secret $(kubectl get sa ${NAMESPACE}-user -n $NAMESPACE -o jsonpath={.secrets..name}) -n $NAMESPACE -o jsonpath='{.data.ca\.crt}')
    server: $(kubectl config view -o jsonpath="{.clusters[?(.name==\"$(kubectl config view -o jsonpath="{.contexts[?(.name==\"$(kubectl config current-context)\")].context.cluster}")\")].cluster.server}")
  name: ${NAMESPACE}-cluster

users:
- name: ${NAMESPACE}-user
  user:
    as-user-extra: {}
    client-key-data: $(kubectl get secret $(kubectl get sa ${NAMESPACE}-user -n $NAMESPACE -o jsonpath={.secrets..name}) -n $NAMESPACE -o jsonpath='{.data.ca\.crt}')
    token: $(kubectl get secret $(kubectl get sa ${NAMESPACE}-user -n $NAMESPACE -o jsonpath={.secrets..name}) -n $NAMESPACE -o jsonpath={.data.token} | base64 --decode)

contexts:
- context:
    cluster: ${NAMESPACE}-cluster
    namespace: ${NAMESPACE}
    user: ${NAMESPACE}-user
  name: ${NAMESPACE}

current-context: ${NAMESPACE}
EOF

Set the KUBECONFIG environment variable for the ${NAMESPACE}-user-config.yaml configuration file:
```
$ export KUBECONFIG=./${NAMESPACE}-user-config.yaml
```
Verify that the configuration took effect by printing the current namespace:
```
$ kubectl config view -o jsonpath="{.contexts[?(@.name==\"$(kubectl config current-context)\")].context.namespace}"
tutorial
```
You should see the name of your namespace in the output.
If you are setting up the cluster for yourself, copy the ${NAMESPACE}-user-config.yaml file mentioned in the previous steps to your local computer, where ${NAMESPACE} is the name of the namespace you provided in the previous steps. For example, tutorial-user-config.yaml. You will need this file later in the tutorial.
If you are an instructor, send the generated configuration files to each participant. The participants must copy their configuration file to their local computer.

Congratulations, you configured your cluster for the tutorial!

You are ready to setup a local computer.

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