Kubernetes Questions | PrepOps.Dev

General 64 questions

#1
Run a command to view all the pods in the current namespace
#2
Run a pod called "nginx-test" using the "nginx" image
#3
Assuming that you have a Pod called "nginx-test", how to remove it?
#4
In what namespace the etcd pod is running? list the pods in that namespace
#5
List pods from all namespaces
#6
Write a YAML of a Pod with two containers and use the YAML file to create the Pod (use whatever images you prefer)
#7
Create a YAML of a Pod without actually running the Pod with the kubectl command (use whatever image you prefer)
#8
How to test a manifest is valid?
#9
How to check which image a certain Pod is using?
#10
How to check how many containers run in single Pod?
#11
Run a Pod called "remo" with the the latest redis image and the label 'year=2017'
#12
List pods and their labels
#13
Delete a Pod called "nm"
#14
List all the pods with the label "env=prod"
#15
Create a static pod with the image python that runs the command sleep 2017
#16
Describe how would you delete a static Pod
#17
List all the namespaces
#18
Create a namespace called 'alle'
#19
Check how many namespaces are there
#20
Check how many pods exist in the "dev" namespace
#21
Create a pod called "kartos" in the namespace dev. The pod should be using the "redis" image.
#22
You are looking for a Pod called "atreus". How to check in which namespace it runs?
#23
Run a command to view all nodes of the cluster
#24
Create a list of all nodes in JSON format and store it in a file called "some_nodes.json"
#25
Check what labels one of your nodes in the cluster has
#26
Check how many services are running in the current namespace
#27
Create an internal service called "sevi" to expose the app 'web' on port 1991
#28
How to reference by name a service called "app-service" within the same namespace?
#29
How to check the TargetPort of a service?
#30
How to check what endpoints the svc has?
#31
How to reference by name a service called "app-service" within a different namespace, called "dev"?
#32
Assume you have a deployment running and you need to create a Service for exposing the pods. This is what is required/known:
- Deployment name: jabulik
- Target port: 8080
- Service type: NodePort
- Selector: jabulik-app
- Port: 8080
#33
How to check how many replicasets defined in the current namespace?
#34
You have a replica set defined to run 3 Pods. You removed one of these 3 pods. What will happen next? how many Pods will there be?
#35
How to check which container image was used as part of replica set called "repli"?
#36
How to check how many Pods are ready as part of a replica set called "repli"?
#37
How to delete a replica set called "rori"?
#38
How to modify a replica set called "rori" to use a different image?
#39
Scale up a replica set called "rori" to run 5 Pods instead of 2
#40
Scale down a replica set called "rori" to run 1 Pod instead of 5
#41
How to list all the deployments in the current namespace?
#42
How to check which image a certain Deployment is using?
#43
Create a file definition/manifest of a deployment called "dep", with 3 replicas that uses the image 'redis'
#44
Remove the deployment depdep
#45
Create a deployment called "pluck" using the image "redis" and make sure it runs 5 replicas
#46
Create a deployment with the following properties:
- called "blufer"
- using the image "python"
- runs 3 replicas
- all pods will be placed on a node that has the label "blufer"
#47
How to schedule a pod on a node called "node1"?
#48
How to list all the Pods with the label "app=web"?
#49
How to list all objects labeled as "env=staging"?
#50
How to list all deployments from "env=prod" and "type=web"?
#51
Check if there are taints on node "master"
#52
Create a taint on one of the nodes in your cluster with key of "app" and value of "web" and effect of "NoSchedule". Verify it was applied
#53
You applied a taint with k taint node minikube app=web:NoSchedule on the only node in your cluster and then executed kubectl run some-pod --image=redis. What will happen?
#54
You applied a taint with k taint node minikube app=web:NoSchedule on the only node in your cluster and then executed kubectl run some-pod --image=redis but the Pod is in pending state. How to fix it?
#55
Remove an existing taint from one of the nodes in your cluster
#56
Check if there are any limits on one of the pods in your cluster
#57
Run a pod called "yay" with the image "python" and resources request of 64Mi memory and 250m CPU
#58
Run a pod called "yay2" with the image "python". Make sure it has resources request of 64Mi memory and 250m CPU and the limits are 128Mi memory and 500m CPU
#59
Deploy metrics-server
#60
Using metrics-server, view the following:
- top performing nodes in the cluster
- top performing Pods
#61
Can you deploy multiple schedulers?
#62
Assuming you have multiple schedulers, how to know which scheduler was used for a given Pod?
#63
You want to run a new Pod and you would like it to be scheduled by a custom scheduler. How to achieve it?
#64
"Killing" Containers
1. Run Pod with a web service (e.g. httpd)
2. Verify the web service is running with the ps command
3. Check how many restarts the pod has performed
4. Kill the web service process
5. Check how many restarts the pod has performed
6. Verify again the web service is running
After you complete the exercise
- Why did the "RESTARTS" count raised?

Troubleshooting Pods 7 questions

#65
You try to run a Pod but see the status "CrashLoopBackOff". What does it means? How to identify the issue?
#66
What the error ImagePullBackOff means?
#67
How to check on which node a certain Pod is running?
#68
Run the following command: kubectl run ohno --image=sheris. Did it work? why not? fix it without removing the Pod and using any image you would like
#69
You try to run a Pod but it's in "Pending" state. What might be the reason?
#70
How to view the logs of a container running in a Pod?
#71
There are two containers inside a Pod called "some-pod". What will happen if you run kubectl logs some-pod

Troubleshooting ReplicaSets 2 questions

#72

Fix the following ReplicaSet definition

apiVersion: apps/v1
kind: ReplicaCet
metadata:
  name: redis
  labels:
    app: redis
    tier: cache
spec:
  selector:
    matchLabels:
      tier: cache
  template:
    metadata:
      labels:
        tier: cachy
    spec:
      containers:
      - name: redis
        image: redis

#73

Fix the following ReplicaSet definition

apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: redis
  labels:
    app: redis
    tier: cache
spec:
  selector:
    matchLabels:
      tier: cache
  template:
    metadata:
      labels:
        tier: cachy
    spec:
      containers:
      - name: redis
        image: redis

Troubleshooting Deployments 2 questions

#74

Fix the following deployment manifest

apiVersion: apps/v1
kind: Deploy
metadata:
  creationTimestamp: null
  labels:
    app: dep
  name: dep
spec:
  replicas: 3
  selector:
    matchLabels:
      app: dep
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: dep
    spec:
      containers:
      - image: redis
        name: redis
        resources: {}
status: {}

#75

Fix the following deployment manifest

apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: dep
  name: dep
spec:
  replicas: 3
  selector:
    matchLabels:
      app: depdep
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: dep
    spec:
      containers:
      - image: redis
        name: redis
        resources: {}
status: {}

Node Affinity 2 questions

#76
Using node affinity, set a Pod to schedule on a node where the key is "region" and value is either "asia" or "emea"
#77
Using node affinity, set a Pod to never schedule on a node where the key is "region" and value is "neverland"

Node Selector 3 questions

#78
Apply the label "hw=max" on one of the nodes in your cluster
#79
Create and run a Pod called some-pod with the image redis and configure it to use the selector hw=max
#80
Explain why node selectors might be limited

Kubernetes 101 9 questions

#81
What is Kubernetes? Why organizations are using it?
#82
When or why NOT to use Kubernetes?
#83
What are some of Kubernetes features?
#84
What Kubernetes objects are there?
#85
What fields are mandatory with any Kubernetes object?
#86
What is kubectl?
#87
What Kubernetes objects do you usually use when deploying applications in Kubernetes?
#88
Why there is no such command in Kubernetes? kubectl get containers
#89
What actions or operations you consider as best practices when it comes to Kubernetes?

Cluster and Architecture 16 questions

#90
What is a Kubernetes Cluster?
#91
What is a Node?
#92
What the master node is responsible for?
#93
Describe shortly and in high-level, what happens when you run kubectl get nodes
#94
True or False? Every cluster must have 0 or more master nodes and at least 1 worker
#95
What are the components of the master node (aka control plane)?
#96
What are the components of a worker node (aka data plane)?
#97
You are managing multiple Kubernetes clusters. How do you quickly change between the clusters using kubectl?
#98
How do you prevent high memory usage in your Kubernetes cluster and possibly issues like memory leak and OOM?
#99
Do you have experience with deploying a Kubernetes cluster? If so, can you describe the process in high-level?
#100
Which command will list all the object types in a cluster?
#101
What kubectl get componentstatus does?
#102
What happens to running pods if if you stop Kubelet on the worker nodes?
#103
Run a command to view all nodes of the cluster
#104
Create a list of all nodes in JSON format and store it in a file called "some_nodes.json"
#105
Check what labels one of your nodes in the cluster has

Pods 40 questions

#106
Explain what is a Pod
#107
Deploy a pod called "my-pod" using the nginx:alpine image
#108
What are your thoughts on "Pods are not meant to be created directly"?
#109
How many containers can a pod contain?
#110
What use cases exist for running multiple containers in a single pod?
#111
What are the possible Pod phases?
#112
True or False? By default, pods are isolated. This means they are unable to receive traffic from any source
#113
True or False? The "Pending" phase means the Pod was not yet accepted by the Kubernetes cluster so the scheduler can't run it unless it's accepted
#114
True or False? A single Pod can be split across multiple nodes
#115
You run a pod and you see the status ContainerCreating
#116
True or False? A volume defined in Pod can be accessed by all the containers of that Pod
#117
What happens when you run a Pod with kubectl?
#118
How to confirm a container is running after running the command kubectl run web --image nginxinc/nginx-unprivileged
#119
After running kubectl run database --image mongo you see the status is "CrashLoopBackOff". What could possibly went wrong and what do you do to confirm?
#120
Explain the purpose of the following lines
```
livenessProbe:
  exec:
    command:
    - cat
    - /appStatus
  initialDelaySeconds: 10
  periodSeconds: 5
```
#121
Explain the purpose of the following lines
```
readinessProbe:
      tcpSocket:
        port: 2017
      initialDelaySeconds: 15
      periodSeconds: 20
```
#122
What does the "ErrImagePull" status of a Pod means?
#123
What happens when you delete a Pod?
#124
Explain liveness probes
#125
Explain readiness probes
#126
How readiness probe status affect Services when they are combined?
#127
Why it's common to have only one container per Pod in most cases?
#128
True or False? Once a Pod is assisgned to a worker node, it will only run on that node, even if it fails at some point and spins up a new Pod
#129
True or False? Each Pod, when created, gets its own public IP address
#130
What are Static Pods?
#131
True or False? The same as there are "Static Pods" there are other static resources like "deployments" and "replicasets"
#132
What are some use cases for using Static Pods?
#133
How to identify which Pods are Static Pods?
#134
Which of the following is not a static pod?:
- kube-scheduler
- kube-proxy
- kube-apiserver
#135
Where static Pods manifests are located?
#136
Describe how would you delete a static Pod
#137
How to check to which worker node the pods were scheduled to? In other words, how to check on which node a certain Pod is running?
#138
How to delete a pod?
#139
List all the pods with the label "env=prod"
#140
How to list the pods in the current namespace?
#141
How view all the pods running in all the namespaces?
#142
You try to run a Pod but it's in "Pending" state. What might be the reason?
#143
What kubectl logs [pod-name] command does?
#144
What kubectl describe pod [pod name] does? command does?
#145
Create a static pod with the image python that runs the command sleep 2017

Labels and Selectors 7 questions

#146
Explain Labels
#147
Explain selectors
#148
Provide some actual examples of how labels are used
#149
What are Annotations?
#150
How annotations different from labels?
#151
How to view the logs of a container running in a Pod?
#152
There are two containers inside a Pod called "some-pod". What will happen if you run kubectl logs some-pod

Deployments 16 questions

#153
What is a "Deployment" in Kubernetes?
#154
How to create a deployment with the image "nginx:alpine"?
#155
How to verify a deployment was created?
#156
How to edit a deployment?
#157
What happens after you edit a deployment and change the image?
#158
How to delete a deployment?
#159
What happens when you delete a deployment?
#160
What happens behind the scenes when you create a Deployment object?
#161
How make an app accessible on private or external network?
#162
Can you use a Deployment for stateful applications?

#163

Fix the following deployment manifest

apiVersion: apps/v1
kind: Deploy
metadata:
  creationTimestamp: null
  labels:
    app: dep
  name: dep
spec:
  replicas: 3
  selector:
    matchLabels:
      app: dep
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: dep
    spec:
      containers:
      - image: redis
        name: redis
        resources: {}
status: {}

#164

Fix the following deployment manifest

apiVersion: apps/v1
kind: Deployment
metadata:
  creationTimestamp: null
  labels:
    app: dep
  name: dep
spec:
  replicas: 3
  selector:
    matchLabels:
      app: depdep
  strategy: {}
  template:
    metadata:
      creationTimestamp: null
      labels:
        app: dep
    spec:
      containers:
      - image: redis
        name: redis
        resources: {}
status: {}

#165
Create a file definition/manifest of a deployment called "dep", with 3 replicas that uses the image 'redis'
#166
Delete the deployment depdep
#167
Create a deployment called "pluck" using the image "redis" and make sure it runs 5 replicas
#168
Create a deployment with the following properties:
- called "blufer"
- using the image "python"
- runs 3 replicas
- all pods will be placed on a node that has the label "blufer"

Services 26 questions

#169
What is a Service in Kubernetes?
#170
How to create a service for an existing deployment called "alle" on port 8080 so the Pod(s) accessible via a Load Balancer?
#171
True or False? The lifecycle of Pods and Services isn't connected so when a Pod dies, the Service still stays
#172
After creating a service, how to check it was created?
#173
What's the default Service type?
#174
What Service types are there?
#175
How Service and Deployment are connected?
#176
What are important steps in defining/adding a Service?
#177
What is the default service type in Kubernetes and what is it used for?
#178
How to get information on a certain service?
#179
What the following command does?
```
kubectl expose rs some-replicaset --name=replicaset-svc --target-port=2017 --type=NodePort
```
#180
True or False? the target port, in the case of running the following command, will be exposed only on one of the Kubernetes cluster nodes but it will routed to all the pods
```
kubectl expose rs some-replicaset --name=replicaset-svc --target-port=2017 --type=NodePort
```
#181
How to verify that a certain service configured to forward the requests to a given pod

#182

Explain what will happen when running apply on the following block

apiVersion: v1
kind: Service
metadata:
  name: some-app
spec:
  type: NodePort
  ports:
  - port: 8080
    nodePort: 2017
    protocol: TCP
  selector:
    type: backend
    service: some-app

#183
How to turn the following service into an external one?
```
spec:
  selector:
    app: some-app
  ports:
    - protocol: TCP
      port: 8081
      targetPort: 8081
```
#184
What would you use to route traffic from outside the Kubernetes cluster to services within a cluster?
#185
True or False? When "NodePort" is used, "ClusterIP" will be created automatically?
#186
When would you use the "LoadBalancer" type
#187
How would you map a service to an external address?
#188
Describe in detail what happens when you create a service
#189
How to list the endpoints of a certain app?
#190
How can you find out information on a Service related to a certain Pod if all you can use is kubectl exec --
#191
Describe what happens when a container tries to connect with its corresponding Service for the first time. Explain who added each of the components you include in your description
#192
Describe in high level what happens when you run kubctl expose deployment remo --type=LoadBalancer --port 8080
#193
After creating a service that forwards incoming external traffic to the containerized application, how to make sure it works?
#194
An internal load balancer in Kubernetes is called ____ and an external load balancer is called ____

Ingress 13 questions

#195
What is Ingress?
#196
Complete the following configuration file to make it Ingress
```
metadata:
  name: someapp-ingress
spec:
```

#197

Explain the meaning of "http", "host" and "backend" directives

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: someapp-ingress
spec:
  rules:
  - host: my.host
    http:
      paths:
      - backend:
          serviceName: someapp-internal-service
          servicePort: 8080

#198
Why using a wildcard in ingress host may lead to issues?
#199
What is Ingress Controller?
#200
What are some use cases for using Ingress?
#201
How to list Ingress in your namespace?
#202
What is Ingress Default Backend?
#203
How to configure a default backend?
#204
How to configure TLS with Ingress?
#205
True or False? When configuring Ingress with TLS, the Secret component must be in the same namespace as the Ingress component
#206
Which Kubernetes concept would you use to control traffic flow at the IP address or port level?
#207
How to scale an application (deplyoment) so it runs more than one instance of the application?

ReplicaSets 26 questions

#208
What is the purpose of ReplicaSet?

#209

What the following block of lines does?

spec:
  replicas: 2
  selector:
    matchLabels:
      type: backend
  template:
    metadata:
      labels:
        type: backend
    spec:
      containers:
      - name: httpd-yup
        image: httpd

#210
What will happen when a Pod, created by ReplicaSet, is deleted directly with kubectl delete po ...?
#211
True or False? If a ReplicaSet defines 2 replicas but there 3 Pods running matching the ReplicaSet selector, it will do nothing
#212
Describe the sequence of events in case of creating a ReplicaSet
#213
How to list ReplicaSets in the current namespace?
#214
Is it possible to delete ReplicaSet without deleting the Pods it created?
#215
What is the default number of replicas if not explicitly specified?
#216
What the following output of kubectl get rs means?
NAME DESIRED CURRENT READY AGE web 2 2 0 2m23s
#217
True or False? Pods specified by the selector field of ReplicaSet must be created by the ReplicaSet itself
#218
True or False? In case of a ReplicaSet, if Pods specified in the selector field don't exists, the ReplicaSet will wait for them to run before doing anything
#219
In case of a ReplicaSet, Which field is mandatory in the spec section?
#220
You've created a ReplicaSet, how to check whether the ReplicaSet found matching Pods or it created new Pods?
#221
True or False? Deleting a ReplicaSet will delete the Pods it created
#222
True or False? Removing the label from a Pod that is tracked by a ReplicaSet, will cause the ReplicaSet to create a new Pod
#223
How to scale a deployment to 8 replicas?
#224
ReplicaSets are running the moment the user executed the command to create them (like kubectl create -f rs.yaml)
#225
How to expose a ReplicaSet as a new service?

#226

Fix the following ReplicaSet definition

apiVersion: apps/v1
kind: ReplicaCet
metadata:
  name: redis
  labels:
    app: redis
    tier: cache
spec:
  selector:
    matchLabels:
      tier: cache
  template:
    metadata:
      labels:
        tier: cachy
    spec:
      containers:
      - name: redis
        image: redis

#227

Fix the following ReplicaSet definition

apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: redis
  labels:
    app: redis
    tier: cache
spec:
  selector:
    matchLabels:
      tier: cache
  template:
    metadata:
      labels:
        tier: cachy
    spec:
      containers:
      - name: redis
        image: redis

#228
How to check which container image was used as part of replica set called "repli"?
#229
How to check how many Pods are ready as part of a replica set called "repli"?
#230
How to delete a replica set called "rori"?
#231
How to modify a replica set called "rori" to use a different image?
#232
Scale up a replica set called "rori" to run 5 Pods instead of 2
#233
Scale down a replica set called "rori" to run 1 Pod instead of 5

DaemonSet 5 questions

#234
What's a DaemonSet?
#235
What's the difference between a ReplicaSet and DaemonSet?
#236
What are some use cases for using a DaemonSet?
#237
How DaemonSet works?
#238
How to list all daemonsets in the current namespace?

StatefulSet 1 question

#239
Explain StatefulSet

Storage 5 questions

#240
What is a volume in regards to Kubernetes?
#241
What volume types are you familiar with?
#242
Which problems, volumes in Kubernetes solve?
#243
Explain ephemeral volume types vs. persistent volumes in regards to Pods
#244
Provide at least one use-case for each of the following volume types:
- emptyDir
- hostPath

Networking 1 question

#245
True or False? By default there is no communication between two Pods in two different namespaces

Network Policies 5 questions

#246
Explain Network Policies
#247
What are some use cases for using Network Policies?
#248
True or False? If no network policies are applied to a pod, then no connections to or from it are allowed
#249
In case of two pods, if there is an egress policy on the source denining traffic and ingress policy on the destination that allows traffic then, traffic will be allowed or denied?
#250
Where Kubernetes cluster stores the cluster state?

etcd 5 questions

#251
What is etcd?
#252
True or False? Etcd holds the current status of any kubernetes component
#253
True or False? The API server is the only component which communicates directly with etcd
#254
True or False? application data is not stored in etcd
#255
Why etcd? Why not some SQL or NoSQL database?

Namespaces 36 questions

#256
What are namespaces?
#257
Why to use namespaces? What is the problem with using one default namespace?
#258
True or False? When a namespace is deleted all resources in that namespace are not deleted but moved to another default namespace
#259
What special namespaces are there by default when creating a Kubernetes cluster?
#260
What can you find in kube-system namespace?
#261
While namespaces do provide scope for resources, they are not isolating them
#262
How to list all namespaces?
#263
Create a namespace called 'alle'
#264
Check how many namespaces are there
#265
Check how many pods exist in the "dev" namespace
#266
Create a pod called "kartos" in the namespace dev. The pod should be using the "redis" image.
#267
You are looking for a Pod called "atreus". How to check in which namespace it runs?
#268
What kube-public contains?
#269
How to get the name of the current namespace?
#270
What kube-node-lease contains?
#271
True or False? With namespaces you can limit the resources consumed by the users/teams
#272
How to switch to another namespace? In other words how to change active namespace?
#273
What is Resource Quota?
#274
How to create a Resource Quota?
#275
Which resources are accessible from different namespaces?
#276
Which service and in which namespace the following file is referencing?
```
apiVersion: v1
kind: ConfigMap
metadata:
  name: some-configmap
data:
  some_url: samurai.jack
```
#277
Which components can't be created within a namespace?
#278
How to list all the components that bound to a namespace?
#279
How to create components in a namespace?
#280
How to execute the command "ls" in an existing pod?
#281
How to create a service that exposes a deployment?
#282
How to create a pod and a service with one command?
#283
Describe in detail what the following command does kubectl create deployment kubernetes-httpd --image=httpd
#284
Why to create kind deployment, if pods can be launched with replicaset?
#285
How to get list of resources which are not bound to a specific namespace?
#286
How to delete all pods whose status is not "Running"?
#287
How to display the resources usages of pods?
#288
Perhaps a general question but, you suspect one of the pods is having issues, you don't know what exactly. What do you do?
#289
What happens what pods are using too much memory? (more than its limit)
#290
Describe how roll-back works
#291
True or False? Memory is a compressible resource, meaning that when a container reach the memory limit, it will keep running

Operators 14 questions

#292
What is an Operator?
#293
Why do we need Operators?
#294
What components the Operator consists of?
#295
Explain CRD
#296
How Operator works?
#297
True or False? Kubernetes Operator used for stateful applications
#298
Explain what is the OLM (Operator Lifecycle Manager) and what is it used for
#299
What is the Operator Framework?
#300
What components the Operator Framework consists of?
#301
Describe in detail what is the Operator Lifecycle Manager
#302
What openshift-operator-lifecycle-manager namespace includes?
#303
What is kubconfig? What do you use it for?
#304
Would you use Helm, Go or something else for creating an Operator?
#305
Are there any tools, projects you are using for building Operators?

Secrets 8 questions

#306
Explain Kubernetes Secrets
#307
How to create a Secret from a key and value?
#308
How to create a Secret from a file?
#309
What type: Opaque in a secret file means? What other types are there?
#310
True or False? storing data in a Secret component makes it automatically secured
#311
What is the problem with the following Secret file:
```
apiVersion: v1
kind: Secret
metadata:
    name: some-secret
type: Opaque
data:
    password: mySecretPassword
```

#312

What the following in a Deployment configuration file means?

spec:
  containers:
    - name: USER_PASSWORD
      valueFrom:
        secretKeyRef:
          name: some-secret
          key: password

#313
How to commit secrets to Git and in general how to use encrypted secrets?

Volumes 15 questions

#314
True or False? Kubernetes provides data persistence out of the box, so when you restart a pod, data is saved
#315
Explain "Persistent Volumes". Why do we need it?
#316
True or False? Persistent Volume must be available to all nodes because the pod can restart on any of them
#317
What types of persistent volumes are there?
#318
What is PersistentVolumeClaim?
#319
Explain Volume Snapshots
#320
True or False? Kubernetes manages data persistence
#321
Explain Storage Classes
#322
Explain "Dynamic Provisioning" and "Static Provisioning"
#323
Explain Access Modes
#324
What is CSI Volume Cloning?
#325
Explain "Ephemeral Volumes"
#326
What types of ephemeral volumes Kubernetes supports?
#327
What is Reclaim Policy?
#328
What reclaim policies are there?

Access Control 8 questions

#329
What is RBAC?
#330
Explain the Role and RoleBinding" objects
#331
What is the difference between Role and ClusterRole objects?
#332
Explain what are "Service Accounts" and in which scenario would use create/use one
#333
What happens you create a pod and you DON'T specify a service account?
#334
Explain how Service Accounts are different from User Accounts
#335
How to list Service Accounts?
#336
Explain "Security Context"

CronJob 3 questions

#337
Explain what is CronJob and what is it used for

#338

What possible issue can arise from using the following spec and how to fix it?

apiVersion: batch/v1beta1
kind: CronJob
metadata:
  name: some-cron-job
spec:
  schedule: '*/1 * * * *'
  startingDeadlineSeconds: 10
  concurrencyPolicy: Allow

#339

What issue might arise from using the following CronJob and how to fix it?

apiVersion: batch/v1beta1
kind: CronJob
metadata:
  name: "some-cron-job"
spec:
  schedule: '*/1 * * * *'
jobTemplate:
  spec:
    template:
      spec:
      restartPolicy: Never
      concurrencyPolicy: Forbid
      successfulJobsHistoryLimit: 1
      failedJobsHistoryLimit: 1

Misc 21 questions

#340
Explain Imperative Management vs. Declarative Management
#341
Explain what Kubernetes Service Discovery means
#342
You have one Kubernetes cluster and multiple teams that would like to use it. You would like to limit the resources each team consumes in the cluster. Which Kubernetes concept would you use for that?
#343
What Kube Proxy does?
#344
What "Resources Quotas" are used for and how?
#345
Explain ConfigMap
#346
How to use ConfigMaps?
#347
True or False? Sensitive data, like credentials, should be stored in a ConfigMap
#348
Explain "Horizontal Pod Autoscaler"
#349
When you delete a pod, is it deleted instantly? (a moment after running the command)
#350
What does being cloud-native mean?
#351
Explain the pet and cattle approach of infrastructure with respect to kubernetes
#352
Describe how you one proceeds to run a containerized web app in K8s, which should be reachable from a public URL.
#353
How would you troubleshoot your cluster if some applications are not reachable any more?
#354
Describe what CustomResourceDefinitions there are in the Kubernetes world? What they can be used for?
#355
How does scheduling work in kubernetes?
#356
How are labels and selectors used?
#357
What QoS classes are there?
#358
Explain Labels. What are they and why would one use them?
#359
Explain Selectors
#360
What is Kubeconfig?

Gatekeeper 2 questions

#361
What is Gatekeeper?
#362
Explain how Gatekeeper works

Policy Testing 2 questions

#363
What is Conftest?
#364
What is Datree? How is it different from Conftest?

Helm 13 questions

#365
What is Helm?
#366
Why do we need Helm? What would be the use case for using it?
#367
Explain "Helm Charts"
#368
It is said that Helm is also Templating Engine. What does it mean?
#369
What are some use cases for using Helm template file?
#370
Explain the Helm Chart Directory Structure
#371
How Helm supports release management?
#372
How do you search for charts?
#373
Is it possible to override values in values.yaml file when installing a chart?
#374
How do you list deployed releases?
#375
How to execute a rollback?
#376
How to view revision history for a certain release?
#377
How to upgrade a release?

Security 1 question

#378
What security best practices do you follow in regards to the Kubernetes cluster?

Troubleshooting Scenarios 2 questions

#379
Running kubectl get pods you see Pods in "Pending" status. What would you do?
#380
Users unable to reach an application running on a Pod on Kubernetes. What might be the issue and how to check?

Istio 1 question

#381
What is Istio? What is it used for?

Controllers 5 questions

#382
What are controllers?
#383
Name two controllers you are familiar with
#384
What process is responsible for running and installing the different controllers?
#385
What is the control loop? How it works?
#386
What are all the phases/steps of a control loop?

Scheduler 9 questions

#387
True of False? The scheduler is responsible for both deciding where a Pod will run and actually running it
#388
How to schedule a pod on a node called "node1"?
#389
Using node affinity, set a Pod to schedule on a node where the key is "region" and value is either "asia" or "emea"
#390
Using node affinity, set a Pod to never schedule on a node where the key is "region" and value is "neverland"
#391
True of False? Using the node affinity type "requiredDuringSchedlingIgnoredDuringExecution" means the scheduler can't schedule unless the rule is met
#392
True of False? Using the node affinity type "preferredDuringSchedlingIgnoredDuringExecution" means the scheduler can't schedule unless the rule is met
#393
Can you deploy multiple schedulers?
#394
Assuming you have multiple schedulers, how to know which scheduler was used for a given Pod?
#395
You want to run a new Pod and you would like it to be scheduled by a custom scheduler. How to achieve it?

Taints 6 questions

#396
Check if there are taints on node "master"
#397
Create a taint on one of the nodes in your cluster with key of "app" and value of "web" and effect of "NoSchedule". Verify it was applied
#398
You applied a taint with k taint node minikube app=web:NoSchedule on the only node in your cluster and then executed kubectl run some-pod --image=redis. What will happen?
#399
You applied a taint with k taint node minikube app=web:NoSchedule on the only node in your cluster and then executed kubectl run some-pod --image=redis but the Pod is in pending state. How to fix it?
#400
Remove an existing taint from one of the nodes in your cluster
#401
What taint effects are there? Explain each one of them

Resource Limits 5 questions

#402
Explain why one would specify resource limits in regards to Pods
#403
True or False? Resource limits applied on a Pod level meaning, if limits is 2gb RAM and there are two container in a Pod that it's 1gb RAM each
#404
Check if there are any limits on one of the pods in your cluster
#405
Run a pod called "yay" with the image "python" and resources request of 64Mi memory and 250m CPU
#406
Run a pod called "yay2" with the image "python". Make sure it has resources request of 64Mi memory and 250m CPU and the limits are 128Mi memory and 500m CPU

Monitoring 2 questions

#407
What monitoring solutions are you familiar with in regards to Kubernetes?
#408
Describe how the monitoring solution you are working with monitors Kubernetes and

Kustomize 3 questions

#409
What is Kustomize?
#410
Explain the need for Kustomize by describing actual use cases
#411
Describe in high-level how Kustomize works

Deployment Strategies 4 questions

#412
What rollout/deployment strategies are you familiar with?
#413
Explain Blue/Green deployments/rollouts in detail
#414
Explain Canary deployments/rollouts in detail
#415
What ways are you familiar with to implement deployment strategies (like canary, blue/green) in Kubernetes?

Scenarios 4 questions

#416
An engineer form your organization told you he is interested only in seeing his team resources in Kubernetes. Instead, in reality, he sees resources of the whole organization, from multiple different teams. What Kubernetes concept can you use in order to deal with it?
#417
An engineer in your team runs a Pod but the status he sees is "CrashLoopBackOff". What does it means? How to identify the issue?
#418
An engineer form your organization asked whether there is a way to prevent from Pods (with cretain label) to be scheduled on one of the nodes in the cluster. Your reply is:
#419
You would like to limit the number of resources being used in your cluster. For example no more than 4 replicasets, 2 services, etc. How would you achieve that?

Kubernetes

After you complete the exercise