Certified Kubernetes Administrator (CKA) Study Guide

Answers to Review Questions

Chapter 2, “Cluster Architecture, Installation, and Configuration”

1. First, create the namespace named apps. Then, we’ll create the ServiceAccount:

   $ kubectl create namespace apps
   $ kubectl create serviceaccount api-access -n apps

   Alternatively, you can use the declarative approach. Create the namespace from the definition in the file apps-namespace.yaml:

   apiVersion: v1
   kind: Namespace
   metadata:
     name: apps

   Create the namespace from the YAML file:

   $ kubectl create -f apps-namespace.yaml

   Create a new YAML file called api-serviceaccount.yaml with the following contents:

   apiVersion: v1
   kind: ServiceAccount
   metadata:
     name: api-access
     namespace: apps

   Run the create command to instantiate the ServiceAccount from the YAML file:

   $ kubectl create -f api-serviceaccount.yaml

2. Use the create clusterrole command to create the ClusterRole imperatively:

   $ kubectl create clusterrole api-clusterrole --verb=watch,list,get \
     --resource=pods

   If you’d rather start with the YAML file, use content shown in the file api-clusterrole.yaml:

   apiVersion: rbac.authorization.k8s.io/v1
   kind: ClusterRole
   metadata:
     name: api-clusterrole
   rules:
   - apiGroups: [""]
     resources: ["pods"]
     verbs: ["watch","list","get"]

   Create the ClusterRole from the YAML file:

   $ kubectl create -f api-clusterrole.yaml

   Use the create clusterrolebinding command to create the ClusterRoleBinding imperatively.

   $ kubectl create clusterrolebinding api-clusterrolebinding \
     --serviceaccount=apps:api-access --clusterrole=api-clusterrole ...