Networking, Load Balancing, Storage and Configuration

What is the role of a Service in Kubernetes?

• Schedules Pods on worker nodes.

• Manages the Deployment Service for Pods.

• Handles storing Secrets and Configuration.

• Provides a single point of entry for accessing one or more Pods.

How do you associate a Service with Pod?

• Use an Annotation

• That is not supported

• Use a Deployment

• Use a Label

Services default to which type unless otherwise specified?

• ClusterIP

• ExternalName

• NodePort

• LoadBanacer

When deploying an app running on a Kubernetes cluster, what would you configure the "service type" as in order to expose the service on the same port of each selected node?

• ClusterIP

• NodePort

• LoadBalancer

• NodeIP

Which of these is feature of service objects?

• The set of pods that a service objects connects to does not change.

• Versioning and healing are provided by service objects.

• The service objects and the pods that they govern are tightly coupled.

• Service objects provide stable static addresses that can be used by external clients.

One of your Pods needs access to a Service that has an associated port that is a published and a cluster IP in in its place. The client Pod's environment variables aren't yet populated, however. Why?

• You must create the Service before creating the client Pods.

• You must create the Service 30 minutes after you create the client Pods.

• You must replace the Domain Name System (DNS) Service Discovery method with the environment variable method.

• You must replace the Domain Name System (DNS) Service Discovery method with the Dynamic Host Configuration Protocol (DHCP) method.

A cluster administrator creatred a StorageClass resource named gce-storage-disk, allowing an storage system to dynamically provision volumes. What actions must a developer take to bind PersistentVolumeClaims (PVC) to PersistentVolumes (PV) of the storage class gce-storage-disk.

• Set the volume.beta.kubernetes.io/storage-class-name: gce-storage-disk annotation on PVC resources.

• Set the volume.beta.kubernetes.io/storage-class-name: gce-storage-disk attribute on PVC resources.

• Set the spec.storageClassName: gce-storage-disk attribute on PVC resources.

• Set the spec.storageClass: gce-storage-disk attribute on PVC resources.

You would like your company's Kubernetes deployments to use dynamic secret values generated as a set of files. Since you manage several clusters, what is the most effective way to handle this?

• Define the secrets as environment variables under the Pod's container.

• Write an init script that downloads the secrets from the Kubernetes API at runtime.

• Run as init container to download the secrets from the Kubernetes API and mount them as a volume to the Pod.

• Attach secrets ffiles to Pods by declaring a volume that will mount each secret as a file in the Pod definition.

In which scenario can you define a Service with a Pod selector?

• When you want to point your Service in a different Namespace or an another cluster.

• When you are migrating a workload to Kubernetes. During the evaluation process, you run only a proportion of your backends in Kubernetes.

• When you want to have an external database cluster in production, but in your test environment you use your own database.

• When you want the controller for the Service selector continuously scanning for Pods to match its selector, and then update an Endpoints if necessary.

Assume you are managing secrets for a Kubernetes Cluster. You have been careful to follow all suggested guidelines and stored all your secrets in Kubernetes objects. How can a secret still become exposed?

• The application reading the secret from the volume and accidentally logging it.

• The secret begin encoded in SHA256 as this is a plain text system.

• A user who can create pods can still edit the value of the secret.

• Anyone with root access on a node has write-access to the secret object.