Prompt:
Explain this bash code:

kubectl scale --replicas 1 deployments/my-nginx --subresource='scale' --type='merge' -p '{"spec":{"replicas": 1}}'

Response: This bash code 4 - Managing Workloads | and allow Kubernetes to add more temporary replicas during a rollout, by setting a surge maximum of 100%:

Context: 4 - Managing Workloads | and allow Kubernetes to add more temporary replicas during a rollout, by setting a surge maximum of 100%:


Prompt:
Explain this bash code:

kubectl patch --type='merge' -p '{"spec":{"strategy":{"rollingUpdate":{"maxSurge": "100%" }}}}'

Response: This bash code 4 - Managing Workloads | To update to version 1.16.1, change .spec.template.spec.containers[0].image from nginx:1.14.2 to nginx:1.16.1 using kubectl edit:

Context: 4 - Managing Workloads | To update to version 1.16.1, change .spec.template.spec.containers[0].image from nginx:1.14.2 to nginx:1.16.1 using kubectl edit:


Prompt:
Explain this bash code:

kubectl edit deployment/my-nginx
# Change the manifest to use the newer container image, then save your changes

Response: This bash code 4 - Managing Workloads | That's it! The Deployment will declaratively update the deployed nginx application progressively behind the scene. It ensures that only a certain number of old replicas may be down while they are bein

Context: 4 - Managing Workloads | That's it! The Deployment will declaratively update the deployed nginx application progressively behind the scene. It ensures that only a certain number of old replicas may be down while they are bein


Prompt:
Complete this bash code:

kubectl apply -f my-deployment.yaml

Response:
# wait for rollout to finish
kubectl rollout status deployment/my-deployment --timeout 10m # 10 minute timeout

Context: 4 - Managing Workloads | or


Prompt:
Explain this bash code:

kubectl apply -f my-deployment.yaml

# wait for rollout to finish
kubectl rollout status deployment/my-deployment --timeout 10m # 10 minute timeout

Response: This bash code 4 - Managing Workloads | or

Context: 4 - Managing Workloads | or


Prompt:
Complete this bash code:

kubectl apply -f backing-stateful-component.yaml

Response:
# don't wait for rollout to finish, just check the status
kubectl rollout status statefulsets/backing-stateful-component --watch=false

Context: 4 - Managing Workloads | You can also pause, resume or cancel a rollout. Visit kubectl rollout to learn more.


Prompt:
Explain this bash code:

kubectl apply -f backing-stateful-component.yaml

# don't wait for rollout to finish, just check the status
kubectl rollout status statefulsets/backing-stateful-component --watch=false

Response: This bash code 4 - Managing Workloads | You can also pause, resume or cancel a rollout. Visit kubectl rollout to learn more.


Prompt:
Explain this bash code:

kubectl annotate pods my-nginx-v4-9gw19 description='my frontend running nginx'
kubectl get pods my-nginx-v4-9gw19 -o yaml

Response: This bash code 4 - Managing Workloads | For more information, see annotations and kubectl annotate.

Context: 4 - Managing Workloads | For more information, see annotations and kubectl annotate.


Prompt:
Complete this yaml code:

apiVersion: v1
kind: pod
metadata:

Response:
  annotations:
    description: my frontend running nginx
...


Prompt:
Explain this yaml code:

apiVersion: v1
kind: pod
metadata:
  annotations:
    description: my frontend running nginx
...

Response: This yaml code 4 - Managing Workloads | For more information, see annotations and kubectl annotate.


Prompt:
Explain this text code:

# This requires an existing source of container and Pod metrics
kubectl autoscale deployment/my-nginx --min=1 --max=3

Response: This text code 4 - Managing Workloads | Now your nginx replicas will be scaled up and down as needed, automatically.

Context: 4 - Managing Workloads | Now your nginx replicas will be scaled up and down as needed, automatically.


Prompt:
Explain this bash code:

kubectl apply -f https://k8s.io/examples/application/nginx/nginx-deployment.yaml

Response: This bash code 4 - Managing Workloads | To learn more about the underlying mechanism, read server-side apply.

Context: 4 - Managing Workloads | To learn more about the underlying mechanism, read server-side apply.


Prompt:
Complete this bash code:

kubectl get deployment my-nginx -o yaml > /tmp/nginx.yaml
vi /tmp/nginx.yaml
# do some edit, and then save the file

Response:
kubectl apply -f /tmp/nginx.yaml
deployment.apps/my-nginx configured

rm /tmp/nginx.yaml

Context: 4 - Managing Workloads | This allows you to do more significant changes more easily. Note that you can specify the editor with your EDITOR or KUBE_EDITOR environment variables.


Prompt:
Explain this bash code:

kubectl get deployment my-nginx -o yaml > /tmp/nginx.yaml
vi /tmp/nginx.yaml
# do some edit, and then save the file

kubectl apply -f /tmp/nginx.yaml
deployment.apps/my-nginx configured

rm /tmp/nginx.yaml

Response: This bash code 4 - Managing Workloads | This allows you to do more significant changes more easily. Note that you can specify the editor with your EDITOR or KUBE_EDITOR environment variables.


Prompt:
Explain this bash code:

kubectl replace -f https://k8s.io/examples/application/nginx/nginx-deployment.yaml --force

Response: This bash code 4 - Managing Workloads | © 2025 The Kubernetes Authors | Documentation Distributed under CC BY 4.0

Context: 4 - Managing Workloads | © 2025 The Kubernetes Authors | Documentation Distributed under CC BY 4.0


Prompt:
Explain this text code:

# List the users that kubectl knows about
  kubectl config get-users

Response: This text code kubectl config get-users | help for get-users

Context: kubectl config get-users | help for get-users


Prompt:
Explain this text code:

# List the users that kubectl knows about
  kubectl config get-users

Response: This text code kubectl config get-users | help for get-users


Prompt:
Explain this bash code:

kubectl describe (-f FILENAME | TYPE [NAME_PREFIX | -l label] | TYPE/NAME)

Response: This bash code kubectl describe | If present, list the requested object(s) across all namespaces. Namespace in current context is ignored even if specified with --namespace.

Context: kubectl describe | If present, list the requested object(s) across all namespaces. Namespace in current context is ignored even if specified with --namespace.


Prompt:
Complete this text code:

# Describe a node
  kubectl describe nodes kubernetes-node-emt8.c.myproject.internal

  # Describe a pod
  kubectl describe pods/nginx

  # Describe a pod identified by type and name in "pod.json"
  kubectl describe -f pod.json

Response:
  # Describe all pods
  kubectl describe pods

  # Describe pods by label name=myLabel
  kubectl describe pods -l name=myLabel

  # Describe all pods managed by the 'frontend' replication controller
  # (rc-created pods get the name of the rc as a prefix in the pod name)
  kubectl describe pods frontend


Prompt:
Explain this text code:

# Describe a node
  kubectl describe nodes kubernetes-node-emt8.c.myproject.internal

  # Describe a pod
  kubectl describe pods/nginx

  # Describe a pod identified by type and name in "pod.json"
  kubectl describe -f pod.json

  # Describe all pods
  kubectl describe pods

  # Describe pods by label name=myLabel
  kubectl describe pods -l name=myLabel

  # Describe all pods managed by the 'frontend' replication controller
  # (rc-created pods get the name of the rc as a prefix in the pod name)
  kubectl describe pods frontend

Response: This text code kubectl describe | If present, list the requested object(s) across all namespaces. Namespace in current context is ignored even if specified with --namespace.


Prompt:
Explain this bash code:

kubectl describe (-f FILENAME | TYPE [NAME_PREFIX | -l label] | TYPE/NAME)

Response: This bash code kubectl describe | If present, list the requested object(s) across all namespaces. Namespace in current context is ignored even if specified with --namespace.


Prompt:
Complete this text code:

# Describe a node
  kubectl describe nodes kubernetes-node-emt8.c.myproject.internal

  # Describe a pod
  kubectl describe pods/nginx

  # Describe a pod identified by type and name in "pod.json"
  kubectl describe -f pod.json

Response:
  # Describe all pods
  kubectl describe pods

  # Describe pods by label name=myLabel
  kubectl describe pods -l name=myLabel

  # Describe all pods managed by the 'frontend' replication controller
  # (rc-created pods get the name of the rc as a prefix in the pod name)
  kubectl describe pods frontend


Prompt:
Explain this text code:

# Describe a node
  kubectl describe nodes kubernetes-node-emt8.c.myproject.internal

  # Describe a pod
  kubectl describe pods/nginx

  # Describe a pod identified by type and name in "pod.json"
  kubectl describe -f pod.json

  # Describe all pods
  kubectl describe pods

  # Describe pods by label name=myLabel
  kubectl describe pods -l name=myLabel

  # Describe all pods managed by the 'frontend' replication controller
  # (rc-created pods get the name of the rc as a prefix in the pod name)
  kubectl describe pods frontend

Response: This text code kubectl describe | If present, list the requested object(s) across all namespaces. Namespace in current context is ignored even if specified with --namespace.


Prompt:
Explain this text code:

container_t, container_init_t, container_kvm_t, container_engine_t

Response: This text code Mapping PodSecurityPolicies to Pod Security Standards | Baseline: Anything

Context: Mapping PodSecurityPolicies to Pod Security Standards | Baseline: Anything


Prompt:
Explain this python code:

import "k8s.io/kube-aggregator/pkg/apis/apiregistration/v1"

Response: This python code APIService | APIService represents a server for a particular GroupVersion. Name must be "version.group".

Context: APIService | APIService represents a server for a particular GroupVersion. Name must be "version.group".


Prompt:
Explain this text code:

Subject: O = kubeadm:cluster-admins, CN = kubernetes-admin

Response: This text code Implementation details | During kubeadm init another kubeconfig file is generated and stored in /etc/kubernetes/super-admin.conf. This file includes a certificate with Subject: O = system:masters, CN = kubernetes-super-admin.

Context: Implementation details | During kubeadm init another kubeconfig file is generated and stored in /etc/kubernetes/super-admin.conf. This file includes a certificate with Subject: O = system:masters, CN = kubernetes-super-admin.


Prompt:
Explain this text code:

Subject: O = system:masters, CN = kubernetes-super-admin

Response: This text code Implementation details | See RBAC user facing role bindings for additional information on RBAC and built-in ClusterRoles and groups.

Context: Implementation details | See RBAC user facing role bindings for additional information on RBAC and built-in ClusterRoles and groups.


Prompt:
Explain this text code:

--requestheader-extra-headers-prefix=X-Remote-Extra-

Response: This text code Implementation details | The static Pod manifest for the controller manager is affected by following parameters provided by the users:

Context: Implementation details | The static Pod manifest for the controller manager is affected by following parameters provided by the users:


Prompt:
Explain this text code:

system:certificates.k8s.io:certificatesigningrequests:nodeclient

Response: This text code Implementation details | The role system:certificates.k8s.io:certificatesigningrequests:nodeclient should be created as well, granting POST permission to /apis/certificates.k8s.io/certificatesigningrequests/nodeclient.

Context: Implementation details | The role system:certificates.k8s.io:certificatesigningrequests:nodeclient should be created as well, granting POST permission to /apis/certificates.k8s.io/certificatesigningrequests/nodeclient.


Prompt:
Explain this text code:

system:certificates.k8s.io:certificatesigningrequests:nodeclient

Response: This text code Implementation details | Kubeadm ensures that certificate rotation is enabled for nodes, and that a new certificate request for nodes will get its CSR request automatically approved by the csrapprover controller.

Context: Implementation details | Kubeadm ensures that certificate rotation is enabled for nodes, and that a new certificate request for nodes will get its CSR request automatically approved by the csrapprover controller.


Prompt:
Explain this text code:

/apis/certificates.k8s.io/certificatesigningrequests/nodeclient

Response: This text code Implementation details | Kubeadm ensures that certificate rotation is enabled for nodes, and that a new certificate request for nodes will get its CSR request automatically approved by the csrapprover controller.


Prompt:
Explain this text code:

system:certificates.k8s.io:certificatesigningrequests:selfnodeclient

Response: This text code Implementation details | This phase creates the cluster-info ConfigMap in the kube-public namespace.

Context: Implementation details | This phase creates the cluster-info ConfigMap in the kube-public namespace.


Prompt:
Complete this text code:

NAME              STATUS   AGE
default           Active   1d

Response:
kube-node-lease   Active   1d
kube-public       Active   1d
kube-system       Active   1d

Context: Namespaces | To set the namespace for a current request, use the --namespace flag.


Prompt:
Explain this text code:

NAME              STATUS   AGE
default           Active   1d
kube-node-lease   Active   1d
kube-public       Active   1d
kube-system       Active   1d

Response: This text code Namespaces | To set the namespace for a current request, use the --namespace flag.


Prompt:
Explain this bash code:

kubectl run nginx --image=nginx --namespace=<insert-namespace-name-here>
kubectl get pods --namespace=<insert-namespace-name-here>

Response: This bash code Namespaces | You can permanently save the namespace for all subsequent kubectl commands in that context.

Context: Namespaces | You can permanently save the namespace for all subsequent kubectl commands in that context.


Prompt:
Explain this bash code:

kubectl config set-context --current --namespace=<insert-namespace-name-here>
# Validate it
kubectl config view --minify | grep namespace:

Response: This bash code Namespaces | When you create a Service, it creates a corresponding DNS entry. This entry is of the form <service-name>.<namespace-name>.svc.cluster.local, which means that if a container only uses <service-name>,

Context: Namespaces | When you create a Service, it creates a corresponding DNS entry. This entry is of the form <service-name>.<namespace-name>.svc.cluster.local, which means that if a container only uses <service-name>,


Prompt:
Complete this text code:

# In a namespace
kubectl api-resources --namespaced=true

Response:
# Not in a namespace
kubectl api-resources --namespaced=false

Context: Namespaces | The Kubernetes control plane sets an immutable label kubernetes.io/metadata.name on all namespaces. The value of the label is the namespace name.


Prompt:
Explain this text code:

# In a namespace
kubectl api-resources --namespaced=true

# Not in a namespace
kubectl api-resources --namespaced=false

Response: This text code Namespaces | The Kubernetes control plane sets an immutable label kubernetes.io/metadata.name on all namespaces. The value of the label is the namespace name.


Prompt:
Complete this text code:

NAME              STATUS   AGE
default           Active   1d

Response:
kube-node-lease   Active   1d
kube-public       Active   1d
kube-system       Active   1d


Prompt:
Explain this text code:

NAME              STATUS   AGE
default           Active   1d
kube-node-lease   Active   1d
kube-public       Active   1d
kube-system       Active   1d

Response: This text code Namespaces | To set the namespace for a current request, use the --namespace flag.


Prompt:
Explain this shell code:

kubectl run nginx --image=nginx --namespace=<insert-namespace-name-here>
kubectl get pods --namespace=<insert-namespace-name-here>

Response: This shell code Namespaces | You can permanently save the namespace for all subsequent kubectl commands in that context.


Prompt:
Explain this shell code:

kubectl config set-context --current --namespace=<insert-namespace-name-here>
# Validate it
kubectl config view --minify | grep namespace:

Response: This shell code Namespaces | When you create a Service, it creates a corresponding DNS entry. This entry is of the form <service-name>.<namespace-name>.svc.cluster.local, which means that if a container only uses <service-name>,


Prompt:
Complete this shell code:

# In a namespace
kubectl api-resources --namespaced=true

Response:
# Not in a namespace
kubectl api-resources --namespaced=false


Prompt:
Explain this shell code:

# In a namespace
kubectl api-resources --namespaced=true

# Not in a namespace
kubectl api-resources --namespaced=false

Response: This shell code Namespaces | The Kubernetes control plane sets an immutable label kubernetes.io/metadata.name on all namespaces. The value of the label is the namespace name.


Prompt:
Explain this bash code:

kubectl run nginx --image=nginx --namespace=<insert-namespace-name-here>
kubectl get pods --namespace=<insert-namespace-name-here>

Response: This bash code Namespaces | You can permanently save the namespace for all subsequent kubectl commands in that context.


Prompt:
Explain this bash code:

kubectl config set-context --current --namespace=<insert-namespace-name-here>
# Validate it
kubectl config view --minify | grep namespace:

Response: This bash code Namespaces | When you create a Service, it creates a corresponding DNS entry. This entry is of the form <service-name>.<namespace-name>.svc.cluster.local, which means that if a container only uses <service-name>,


Prompt:
Complete this text code:

# In a namespace
kubectl api-resources --namespaced=true

Response:
# Not in a namespace
kubectl api-resources --namespaced=false


Prompt:
Explain this text code:

# In a namespace
kubectl api-resources --namespaced=true

# Not in a namespace
kubectl api-resources --namespaced=false

Response: This text code Namespaces | The Kubernetes control plane sets an immutable label kubernetes.io/metadata.name on all namespaces. The value of the label is the namespace name.


Prompt:
Complete this yaml code:

apiVersion: v1
kind: Pod
metadata:
  name: redis
spec:
  containers:
  - name: redis

Response:
    image: redis
    volumeMounts:
    - name: redis-storage
      mountPath: /data/redis
  volumes:
  - name: redis-storage
    emptyDir: {}

Context: Configure a Pod to Use a Volume for Storage | Create the Pod:


Prompt:
Explain this yaml code:

apiVersion: v1
kind: Pod
metadata:
  name: redis
spec:
  containers:
  - name: redis
    image: redis
    volumeMounts:
    - name: redis-storage
      mountPath: /data/redis
  volumes:
  - name: redis-storage
    emptyDir: {}

Response: This yaml code Configure a Pod to Use a Volume for Storage | Create the Pod:


Prompt:
Explain this bash code:

kubectl apply -f https://k8s.io/examples/pods/storage/redis.yaml

Response: This bash code Configure a Pod to Use a Volume for Storage | Verify that the Pod's Container is running, and then watch for changes to the Pod:

Context: Configure a Pod to Use a Volume for Storage | Verify that the Pod's Container is running, and then watch for changes to the Pod:


Prompt:
Explain this text code:

NAME      READY     STATUS    RESTARTS   AGE
redis     1/1       Running   0          13s

Response: This text code Configure a Pod to Use a Volume for Storage | In another terminal, get a shell to the running Container:

Context: Configure a Pod to Use a Volume for Storage | In another terminal, get a shell to the running Container:


Prompt:
Explain this text code:

root@redis:/data# cd /data/redis/
root@redis:/data/redis# echo Hello > test-file

Response: This text code Configure a Pod to Use a Volume for Storage | In your shell, list the running processes:

Context: Configure a Pod to Use a Volume for Storage | In your shell, list the running processes:


Prompt:
Explain this text code:

root@redis:/data/redis# apt-get update
root@redis:/data/redis# apt-get install procps
root@redis:/data/redis# ps aux

Response: This text code Configure a Pod to Use a Volume for Storage | The output is similar to this:

Context: Configure a Pod to Use a Volume for Storage | The output is similar to this:


Prompt:
Complete this text code:

USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
redis        1  0.1  0.1  33308  3828 ?        Ssl  00:46   0:00 redis-server *:6379

Response:
root        12  0.0  0.0  20228  3020 ?        Ss   00:47   0:00 /bin/bash
root        15  0.0  0.0  17500  2072 ?        R+   00:48   0:00 ps aux

Context: Configure a Pod to Use a Volume for Storage | In your shell, kill the Redis process:


Prompt:
Explain this text code:

USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
redis        1  0.1  0.1  33308  3828 ?        Ssl  00:46   0:00 redis-server *:6379
root        12  0.0  0.0  20228  3020 ?        Ss   00:47   0:00 /bin/bash
root        15  0.0  0.0  17500  2072 ?        R+   00:48   0:00 ps aux

Response: This text code Configure a Pod to Use a Volume for Storage | In your shell, kill the Redis process:


Prompt:
Complete this text code:

NAME      READY     STATUS     RESTARTS   AGE
redis     1/1       Running    0          13s

Response:
redis     0/1       Completed  0         6m
redis     1/1       Running    1         6m

Context: Configure a Pod to Use a Volume for Storage | At this point, the Container has terminated and restarted. This is because the Redis Pod has a restartPolicy of Always.


Prompt:
Explain this text code:

NAME      READY     STATUS     RESTARTS   AGE
redis     1/1       Running    0          13s
redis     0/1       Completed  0         6m
redis     1/1       Running    1         6m

Response: This text code Configure a Pod to Use a Volume for Storage | At this point, the Container has terminated and restarted. This is because the Redis Pod has a restartPolicy of Always.


Prompt:
Explain this text code:

root@redis:/data/redis# cd /data/redis/
root@redis:/data/redis# ls
test-file

Response: This text code Configure a Pod to Use a Volume for Storage | Delete the Pod that you created for this exercise:

Context: Configure a Pod to Use a Volume for Storage | Delete the Pod that you created for this exercise:


Prompt:
Complete this yaml code:

apiVersion: v1
kind: Pod
metadata:
  name: redis
spec:
  containers:
  - name: redis

Response:
    image: redis
    volumeMounts:
    - name: redis-storage
      mountPath: /data/redis
  volumes:
  - name: redis-storage
    emptyDir: {}


Prompt:
Explain this yaml code:

apiVersion: v1
kind: Pod
metadata:
  name: redis
spec:
  containers:
  - name: redis
    image: redis
    volumeMounts:
    - name: redis-storage
      mountPath: /data/redis
  volumes:
  - name: redis-storage
    emptyDir: {}

Response: This yaml code Configure a Pod to Use a Volume for Storage | Create the Pod:


Prompt:
Explain this shell code:

kubectl apply -f https://k8s.io/examples/pods/storage/redis.yaml

Response: This shell code Configure a Pod to Use a Volume for Storage | Verify that the Pod's Container is running, and then watch for changes to the Pod:


Prompt:
Explain this console code:

NAME      READY     STATUS    RESTARTS   AGE
redis     1/1       Running   0          13s

Response: This console code Configure a Pod to Use a Volume for Storage | In another terminal, get a shell to the running Container:


Prompt:
Explain this shell code:

root@redis:/data# cd /data/redis/
root@redis:/data/redis# echo Hello > test-file

Response: This shell code Configure a Pod to Use a Volume for Storage | In your shell, list the running processes:


Prompt:
Explain this shell code:

root@redis:/data/redis# apt-get update
root@redis:/data/redis# apt-get install procps
root@redis:/data/redis# ps aux

Response: This shell code Configure a Pod to Use a Volume for Storage | The output is similar to this:


Prompt:
Complete this console code:

USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
redis        1  0.1  0.1  33308  3828 ?        Ssl  00:46   0:00 redis-server *:6379

Response:
root        12  0.0  0.0  20228  3020 ?        Ss   00:47   0:00 /bin/bash
root        15  0.0  0.0  17500  2072 ?        R+   00:48   0:00 ps aux


Prompt:
Explain this console code:

USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
redis        1  0.1  0.1  33308  3828 ?        Ssl  00:46   0:00 redis-server *:6379
root        12  0.0  0.0  20228  3020 ?        Ss   00:47   0:00 /bin/bash
root        15  0.0  0.0  17500  2072 ?        R+   00:48   0:00 ps aux

Response: This console code Configure a Pod to Use a Volume for Storage | In your shell, kill the Redis process:


Prompt:
Complete this console code:

NAME      READY     STATUS     RESTARTS   AGE
redis     1/1       Running    0          13s

Response:
redis     0/1       Completed  0         6m
redis     1/1       Running    1         6m


Prompt:
Explain this console code:

NAME      READY     STATUS     RESTARTS   AGE
redis     1/1       Running    0          13s
redis     0/1       Completed  0         6m
redis     1/1       Running    1         6m

Response: This console code Configure a Pod to Use a Volume for Storage | At this point, the Container has terminated and restarted. This is because the Redis Pod has a restartPolicy of Always.


Prompt:
Explain this shell code:

root@redis:/data/redis# cd /data/redis/
root@redis:/data/redis# ls
test-file

Response: This shell code Configure a Pod to Use a Volume for Storage | Delete the Pod that you created for this exercise:


Prompt:
Complete this yaml code:

pods/storage/redis.yaml
apiVersion: v1
kind: Pod
metadata:
  name: redis
spec:
  containers:

Response:
  - name: redis
    image: redis
    volumeMounts:
    - name: redis-storage
      mountPath: /data/redis
  volumes:
  - name: redis-storage
    emptyDir: {}


Prompt:
Explain this yaml code:

pods/storage/redis.yaml
apiVersion: v1
kind: Pod
metadata:
  name: redis
spec:
  containers:
  - name: redis
    image: redis
    volumeMounts:
    - name: redis-storage
      mountPath: /data/redis
  volumes:
  - name: redis-storage
    emptyDir: {}

Response: This yaml code Configure a Pod to Use a Volume for Storage | Create the Pod:


Prompt:
Complete this yaml code:

apiVersion: v1
kind: Pod
metadata:
  name: redis
spec:
  containers:
  - name: redis

Response:
    image: redis
    volumeMounts:
    - name: redis-storage
      mountPath: /data/redis
  volumes:
  - name: redis-storage
    emptyDir: {}


Prompt:
Explain this yaml code:

apiVersion: v1
kind: Pod
metadata:
  name: redis
spec:
  containers:
  - name: redis
    image: redis
    volumeMounts:
    - name: redis-storage
      mountPath: /data/redis
  volumes:
  - name: redis-storage
    emptyDir: {}

Response: This yaml code Configure a Pod to Use a Volume for Storage | Create the Pod:


Prompt:
Explain this bash code:

kubectl apply -f https://k8s.io/examples/pods/storage/redis.yaml

Response: This bash code Configure a Pod to Use a Volume for Storage | Verify that the Pod's Container is running, and then watch for changes to the Pod:


Prompt:
Explain this text code:

NAME      READY     STATUS    RESTARTS   AGE
redis     1/1       Running   0          13s

Response: This text code Configure a Pod to Use a Volume for Storage | In another terminal, get a shell to the running Container:


Prompt:
Explain this text code:

root@redis:/data# cd /data/redis/
root@redis:/data/redis# echo Hello > test-file

Response: This text code Configure a Pod to Use a Volume for Storage | In your shell, list the running processes:


Prompt:
Explain this text code:

root@redis:/data/redis# apt-get update
root@redis:/data/redis# apt-get install procps
root@redis:/data/redis# ps aux

Response: This text code Configure a Pod to Use a Volume for Storage | The output is similar to this:


Prompt:
Complete this text code:

USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
redis        1  0.1  0.1  33308  3828 ?        Ssl  00:46   0:00 redis-server *:6379

Response:
root        12  0.0  0.0  20228  3020 ?        Ss   00:47   0:00 /bin/bash
root        15  0.0  0.0  17500  2072 ?        R+   00:48   0:00 ps aux


Prompt:
Explain this text code:

USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
redis        1  0.1  0.1  33308  3828 ?        Ssl  00:46   0:00 redis-server *:6379
root        12  0.0  0.0  20228  3020 ?        Ss   00:47   0:00 /bin/bash
root        15  0.0  0.0  17500  2072 ?        R+   00:48   0:00 ps aux

Response: This text code Configure a Pod to Use a Volume for Storage | In your shell, kill the Redis process:


Prompt:
Complete this text code:

NAME      READY     STATUS     RESTARTS   AGE
redis     1/1       Running    0          13s

Response:
redis     0/1       Completed  0         6m
redis     1/1       Running    1         6m


Prompt:
Explain this text code:

NAME      READY     STATUS     RESTARTS   AGE
redis     1/1       Running    0          13s
redis     0/1       Completed  0         6m
redis     1/1       Running    1         6m

Response: This text code Configure a Pod to Use a Volume for Storage | At this point, the Container has terminated and restarted. This is because the Redis Pod has a restartPolicy of Always.


Prompt:
Explain this text code:

root@redis:/data/redis# cd /data/redis/
root@redis:/data/redis# ls
test-file

Response: This text code Configure a Pod to Use a Volume for Storage | Delete the Pod that you created for this exercise:


Prompt:
Complete this text code:

$ telepresence connect

Response:
Launching Telepresence Daemon
...
Connected to context default (https://<cluster public IP>)

Context: Developing and debugging services locally using telepresence | You can curl services using the Kubernetes syntax e.g. curl -ik https://kubernetes.default


Prompt:
Explain this text code:

$ telepresence connect

Launching Telepresence Daemon
...
Connected to context default (https://<cluster public IP>)

Response: This text code Developing and debugging services locally using telepresence | You can curl services using the Kubernetes syntax e.g. curl -ik https://kubernetes.default


Prompt:
Complete this text code:

$ telepresence connect

Response:
Launching Telepresence Daemon
...
Connected to context default (https://<cluster public IP>)


Prompt:
Explain this text code:

$ telepresence connect

Launching Telepresence Daemon
...
Connected to context default (https://<cluster public IP>)

Response: This text code Developing and debugging services locally using telepresence | You can curl services using the Kubernetes syntax e.g. curl -ik https://kubernetes.default


Prompt:
Explain this text code:

telepresence intercept $SERVICE_NAME --port $LOCAL_PORT:$REMOTE_PORT

Response: This text code Developing and debugging services locally using telepresence | Where:

Context: Developing and debugging services locally using telepresence | Where:


Prompt:
Explain this text code:

kubeadm upgrade apply phase bootstrap-token [flags]

Response: This text code kubeadm upgrade phases | Path to a kubeadm configuration file.

Context: kubeadm upgrade phases | Path to a kubeadm configuration file.


Prompt:
Explain this text code:

kubeadm upgrade apply phase bootstrap-token [flags]

Response: This text code kubeadm upgrade phases | Path to a kubeadm configuration file.


Prompt:
Explain this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
encryptionAlgorithm: <ALGORITHM>

Response: This yaml code Certificate Management with kubeadm | <ALGORITHM> can be one of RSA-2048 (default), RSA-3072, RSA-4096 or ECDSA-P256.

Context: Certificate Management with kubeadm | <ALGORITHM> can be one of RSA-2048 (default), RSA-3072, RSA-4096 or ECDSA-P256.


Prompt:
Complete this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration

Response:
certificateValidityPeriod: 8760h # Default: 365 days × 24 hours = 1 year
caCertificateValidityPeriod: 87600h # Default: 365 days × 24 hours * 10 = 10 years

Context: Certificate Management with kubeadm | The values of the fields follow the accepted format for Go's time.Duration values, with the longest supported unit being h (hours).


Prompt:
Explain this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
certificateValidityPeriod: 8760h # Default: 365 days × 24 hours = 1 year
caCertificateValidityPeriod: 87600h # Default: 365 days × 24 hours * 10 = 10 years

Response: This yaml code Certificate Management with kubeadm | The values of the fields follow the accepted format for Go's time.Duration values, with the longest supported unit being h (hours).


Prompt:
Complete this text code:

CERTIFICATE                EXPIRES                  RESIDUAL TIME   CERTIFICATE AUTHORITY   EXTERNALLY MANAGED
admin.conf                 Dec 30, 2020 23:36 UTC   364d                                    no
apiserver                  Dec 30, 2020 23:36 UTC   364d            ca                      no
apiserver-etcd-client      Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
apiserver-kubelet-client   Dec 30, 2020 23:36 UTC   364d            ca                      no
controller-manager.conf    Dec 30, 2020 23:36 UTC   364d                                    no
etcd-healthcheck-client    Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
etcd-peer                  Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no

Response:
etcd-server                Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
front-proxy-client         Dec 30, 2020 23:36 UTC   364d            front-proxy-ca          no
scheduler.conf             Dec 30, 2020 23:36 UTC   364d                                    no

CERTIFICATE AUTHORITY   EXPIRES                  RESIDUAL TIME   EXTERNALLY MANAGED
ca                      Dec 28, 2029 23:36 UTC   9y              no
etcd-ca                 Dec 28, 2029 23:36 UTC   9y              no
front-proxy-ca          Dec 28, 2029 23:36 UTC   9y              no

Context: Certificate Management with kubeadm | The command shows expiration/residual time for the client certificates in the /etc/kubernetes/pki folder and for the client certificate embedded in the kubeconfig files used by kubeadm (admin.conf, co


Prompt:
Explain this text code:

CERTIFICATE                EXPIRES                  RESIDUAL TIME   CERTIFICATE AUTHORITY   EXTERNALLY MANAGED
admin.conf                 Dec 30, 2020 23:36 UTC   364d                                    no
apiserver                  Dec 30, 2020 23:36 UTC   364d            ca                      no
apiserver-etcd-client      Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
apiserver-kubelet-client   Dec 30, 2020 23:36 UTC   364d            ca                      no
controller-manager.conf    Dec 30, 2020 23:36 UTC   364d                                    no
etcd-healthcheck-client    Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
etcd-peer                  Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
etcd-server                Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
front-proxy-client         Dec 30, 2020 23:36 UTC   364d            front-proxy-ca          no
scheduler.conf             Dec 30, 2020 23:36 UTC   364d                                    no

CERTIFICATE AUTHORITY   EXPIRES                  RESIDUAL TIME   EXTERNALLY MANAGED
ca                      Dec 28, 2029 23:36 UTC   9y              no
etcd-ca                 Dec 28, 2029 23:36 UTC   9y              no
front-proxy-ca          Dec 28, 2029 23:36 UTC   9y              no

Response: This text code Certificate Management with kubeadm | The command shows expiration/residual time for the client certificates in the /etc/kubernetes/pki folder and for the client certificate embedded in the kubeconfig files used by kubeadm (admin.conf, co


Prompt:
Explain this text code:

client-certificate: /var/lib/kubelet/pki/kubelet-client-current.pem
client-key: /var/lib/kubelet/pki/kubelet-client-current.pem

Response: This text code Certificate Management with kubeadm | kubeadm renews all the certificates during control plane upgrade.

Context: Certificate Management with kubeadm | kubeadm renews all the certificates during control plane upgrade.


Prompt:
Explain this text code:

# If you are running cluster with a replicated control plane, this command
# needs to be executed on all the control-plane nodes.
kubeadm certs renew all

Response: This text code Certificate Management with kubeadm | Clusters built with kubeadm often copy the admin.conf certificate into $HOME/.kube/config, as instructed in Creating a cluster with kubeadm. On such a system, to update the contents of $HOME/.kube/con

Context: Certificate Management with kubeadm | Clusters built with kubeadm often copy the admin.conf certificate into $HOME/.kube/config, as instructed in Creating a cluster with kubeadm. On such a system, to update the contents of $HOME/.kube/con


Prompt:
Explain this text code:

sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

Response: This text code Certificate Management with kubeadm | This section provides more details about how to execute manual certificate renewal using the Kubernetes certificates API.

Context: Certificate Management with kubeadm | This section provides more details about how to execute manual certificate renewal using the Kubernetes certificates API.


Prompt:
Complete this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
controllerManager:
  extraArgs:

Response:
  - name: "cluster-signing-cert-file"
    value: "/etc/kubernetes/pki/ca.crt"
  - name: "cluster-signing-key-file"
    value: "/etc/kubernetes/pki/ca.key"

Context: Certificate Management with kubeadm | See Create CertificateSigningRequest for creating CSRs with the Kubernetes API.


Prompt:
Explain this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
controllerManager:
  extraArgs:
  - name: "cluster-signing-cert-file"
    value: "/etc/kubernetes/pki/ca.crt"
  - name: "cluster-signing-key-file"
    value: "/etc/kubernetes/pki/ca.key"

Response: This yaml code Certificate Management with kubeadm | See Create CertificateSigningRequest for creating CSRs with the Kubernetes API.


Prompt:
Complete this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
---

Response:
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
serverTLSBootstrap: true

Context: Certificate Management with kubeadm | If you have already created the cluster you must adapt it by doing the following:


Prompt:
Explain this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
---
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
serverTLSBootstrap: true

Response: This yaml code Certificate Management with kubeadm | If you have already created the cluster you must adapt it by doing the following:


Prompt:
Explain this text code:

NAME        AGE     SIGNERNAME                        REQUESTOR                      CONDITION
csr-9wvgt   112s    kubernetes.io/kubelet-serving     system:node:worker-1           Pending
csr-lz97v   1m58s   kubernetes.io/kubelet-serving     system:node:control-plane-1    Pending

Response: This text code Certificate Management with kubeadm | To approve them you can do the following:

Context: Certificate Management with kubeadm | To approve them you can do the following:


Prompt:
Complete this yaml code:

# example.yaml
apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
# Will be used as the target "cluster" in the kubeconfig

Response:
clusterName: "kubernetes"
# Will be used as the "server" (IP or DNS name) of this cluster in the kubeconfig
controlPlaneEndpoint: "some-dns-address:6443"
# The cluster CA key and certificate will be loaded from this local directory
certificatesDir: "/etc/kubernetes/pki"

Context: Certificate Management with kubeadm | Make sure that these settings match the desired target cluster settings. To see the settings of an existing cluster use:


Prompt:
Explain this yaml code:

# example.yaml
apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
# Will be used as the target "cluster" in the kubeconfig
clusterName: "kubernetes"
# Will be used as the "server" (IP or DNS name) of this cluster in the kubeconfig
controlPlaneEndpoint: "some-dns-address:6443"
# The cluster CA key and certificate will be loaded from this local directory
certificatesDir: "/etc/kubernetes/pki"

Response: This yaml code Certificate Management with kubeadm | Make sure that these settings match the desired target cluster settings. To see the settings of an existing cluster use:


Prompt:
Explain this bash code:

kubectl get cm kubeadm-config -n kube-system -o=jsonpath="{.data.ClusterConfiguration}"

Response: This bash code Certificate Management with kubeadm | The following example will generate a kubeconfig file with credentials valid for 24 hours for a new user johndoe that is part of the appdevs group:

Context: Certificate Management with kubeadm | The following example will generate a kubeconfig file with credentials valid for 24 hours for a new user johndoe that is part of the appdevs group:


Prompt:
Explain this text code:

kubeadm kubeconfig user --config example.yaml --org appdevs --client-name johndoe --validity-period 24h

Response: This text code Certificate Management with kubeadm | The following example will generate a kubeconfig file with administrator credentials valid for 1 week:

Context: Certificate Management with kubeadm | The following example will generate a kubeconfig file with administrator credentials valid for 1 week:


Prompt:
Explain this text code:

kubeadm kubeconfig user --config example.yaml --client-name admin --validity-period 168h

Response: This text code Certificate Management with kubeadm | You can create certificate signing requests with kubeadm certs generate-csr. Calling this command will generate .csr / .key file pairs for regular certificates. For certificates embedded in kubeconfig

Context: Certificate Management with kubeadm | You can create certificate signing requests with kubeadm certs generate-csr. Calling this command will generate .csr / .key file pairs for regular certificates. For certificates embedded in kubeconfig


Prompt:
Complete this text code:

sudo kubeadm init phase certs ca
sudo kubeadm init phase certs etcd-ca

Response:
sudo kubeadm init phase certs front-proxy-ca
sudo kubeadm init phase certs sa

Context: Certificate Management with kubeadm | This will populate the folders /etc/kubernetes/pki and /etc/kubernetes/pki/etcd with all self-signed CA files (certificates and keys) and service account (public and private keys) that kubeadm needs f


Prompt:
Explain this text code:

sudo kubeadm init phase certs ca
sudo kubeadm init phase certs etcd-ca
sudo kubeadm init phase certs front-proxy-ca
sudo kubeadm init phase certs sa

Response: This text code Certificate Management with kubeadm | This will populate the folders /etc/kubernetes/pki and /etc/kubernetes/pki/etcd with all self-signed CA files (certificates and keys) and service account (public and private keys) that kubeadm needs f


Prompt:
Complete this text code:

#!/bin/bash

# Set certificate expiration time in days
DAYS=365

# Process all CSR files except those for front-proxy and etcd
find ./ -name "*.csr" | grep -v "pki/etcd" | grep -v "front-proxy" | while read -r FILE;
do
    echo "* Processing ${FILE} ..."
    FILE=${FILE%.*} # Trim the extension
    if [ -f "./pki/ca.srl" ]; then
        SERIAL_FLAG="-CAserial ./pki/ca.srl"
    else
        SERIAL_FLAG="-CAcreateserial"
    fi
    openssl x509 -req -days "${DAYS}" -CA ./pki/ca.crt -CAkey ./pki/ca.key ${SERIAL_FLAG} \
        -in "${FILE}.csr" -out "${FILE}.crt"
    sleep 2
done

Response:
# Process all etcd CSRs
find ./pki/etcd -name "*.csr" | while read -r FILE;
do
    echo "* Processing ${FILE} ..."
    FILE=${FILE%.*} # Trim the extension
    if [ -f "./pki/etcd/ca.srl" ]; then
        SERIAL_FLAG=-CAserial ./pki/etcd/ca.srl
    else
        SERIAL_FLAG=-CAcreateserial
    fi
    openssl x509 -req -days "${DAYS}" -CA ./pki/etcd/ca.crt -CAkey ./pki/etcd/ca.key ${SERIAL_FLAG} \
        -in "${FILE}.csr" -out "${FILE}.crt"
done

# Process front-proxy CSRs
echo "* Processing ./pki/front-proxy-client.csr ..."
openssl x509 -req -days "${DAYS}" -CA ./pki/front-proxy-ca.crt -CAkey ./pki/front-proxy-ca.key -CAcreateserial \
    -in ./pki/front-proxy-client.csr -out ./pki/front-proxy-client.crt

Context: Certificate Management with kubeadm | Repeat this step for all nodes that have CSR files.


Prompt:
Explain this text code:

#!/bin/bash

# Set certificate expiration time in days
DAYS=365

# Process all CSR files except those for front-proxy and etcd
find ./ -name "*.csr" | grep -v "pki/etcd" | grep -v "front-proxy" | while read -r FILE;
do
    echo "* Processing ${FILE} ..."
    FILE=${FILE%.*} # Trim the extension
    if [ -f "./pki/ca.srl" ]; then
        SERIAL_FLAG="-CAserial ./pki/ca.srl"
    else
        SERIAL_FLAG="-CAcreateserial"
    fi
    openssl x509 -req -days "${DAYS}" -CA ./pki/ca.crt -CAkey ./pki/ca.key ${SERIAL_FLAG} \
        -in "${FILE}.csr" -out "${FILE}.crt"
    sleep 2
done

# Process all etcd CSRs
find ./pki/etcd -name "*.csr" | while read -r FILE;
do
    echo "* Processing ${FILE} ..."
    FILE=${FILE%.*} # Trim the extension
    if [ -f "./pki/etcd/ca.srl" ]; then
        SERIAL_FLAG=-CAserial ./pki/etcd/ca.srl
    else
        SERIAL_FLAG=-CAcreateserial
    fi
    openssl x509 -req -days "${DAYS}" -CA ./pki/etcd/ca.crt -CAkey ./pki/etcd/ca.key ${SERIAL_FLAG} \
        -in "${FILE}.csr" -out "${FILE}.crt"
done

# Process front-proxy CSRs
echo "* Processing ./pki/front-proxy-client.csr ..."
openssl x509 -req -days "${DAYS}" -CA ./pki/front-proxy-ca.crt -CAkey ./pki/front-proxy-ca.key -CAcreateserial \
    -in ./pki/front-proxy-client.csr -out ./pki/front-proxy-client.crt

Response: This text code Certificate Management with kubeadm | Repeat this step for all nodes that have CSR files.


Prompt:
Complete this text code:

#!/bin/bash

CLUSTER=kubernetes
find ./ -name "*.conf" | while read -r FILE;
do

Response:
    echo "* Processing ${FILE} ..."
    KUBECONFIG="${FILE}" kubectl config set-cluster "${CLUSTER}" --certificate-authority ./pki/ca.crt --embed-certs
    USER=$(KUBECONFIG="${FILE}" kubectl config view -o jsonpath='{.users[0].name}')
    KUBECONFIG="${FILE}" kubectl config set-credentials "${USER}" --client-certificate "${FILE}.crt" --embed-certs
done

Context: Certificate Management with kubeadm | Perform this step on all nodes that have CSR files.


Prompt:
Explain this text code:

#!/bin/bash

CLUSTER=kubernetes
find ./ -name "*.conf" | while read -r FILE;
do
    echo "* Processing ${FILE} ..."
    KUBECONFIG="${FILE}" kubectl config set-cluster "${CLUSTER}" --certificate-authority ./pki/ca.crt --embed-certs
    USER=$(KUBECONFIG="${FILE}" kubectl config view -o jsonpath='{.users[0].name}')
    KUBECONFIG="${FILE}" kubectl config set-credentials "${USER}" --client-certificate "${FILE}.crt" --embed-certs
done

Response: This text code Certificate Management with kubeadm | Perform this step on all nodes that have CSR files.


Prompt:
Complete this text code:

#!/bin/bash

# Cleanup CSR files

Response:
rm -f ./*.csr ./pki/*.csr ./pki/etcd/*.csr # Clean all CSR files

# Cleanup CRT files that were already embedded in kubeconfig files
rm -f ./*.crt

Context: Certificate Management with kubeadm | Optionally, move .srl files to the next node to be processed.


Prompt:
Explain this text code:

#!/bin/bash

# Cleanup CSR files
rm -f ./*.csr ./pki/*.csr ./pki/etcd/*.csr # Clean all CSR files

# Cleanup CRT files that were already embedded in kubeconfig files
rm -f ./*.crt

Response: This text code Certificate Management with kubeadm | Optionally, move .srl files to the next node to be processed.


Prompt:
Explain this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
encryptionAlgorithm: <ALGORITHM>

Response: This yaml code Certificate Management with kubeadm | <ALGORITHM> can be one of RSA-2048 (default), RSA-3072, RSA-4096 or ECDSA-P256.

Context: Certificate Management with kubeadm | <ALGORITHM> can be one of RSA-2048 (default), RSA-3072, RSA-4096 or ECDSA-P256.


Prompt:
Complete this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration

Response:
certificateValidityPeriod: 8760h # Default: 365 days × 24 hours = 1 year
caCertificateValidityPeriod: 87600h # Default: 365 days × 24 hours * 10 = 10 years

Context: Certificate Management with kubeadm | The values of the fields follow the accepted format for Go's time.Duration values, with the longest supported unit being h (hours).


Prompt:
Explain this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
certificateValidityPeriod: 8760h # Default: 365 days × 24 hours = 1 year
caCertificateValidityPeriod: 87600h # Default: 365 days × 24 hours * 10 = 10 years

Response: This yaml code Certificate Management with kubeadm | The values of the fields follow the accepted format for Go's time.Duration values, with the longest supported unit being h (hours).


Prompt:
Explain this text code:

kubeadm init phase kubeconfig all --config config.yaml

Response: This text code Certificate Management with kubeadm | Once the credentials are prepared on all nodes, call kubeadm init and kubeadm join for these nodes to join the cluster. kubeadm will use the existing kubeconfig and certificate files under /etc/kubern

Context: Certificate Management with kubeadm | Once the credentials are prepared on all nodes, call kubeadm init and kubeadm join for these nodes to join the cluster. kubeadm will use the existing kubeconfig and certificate files under /etc/kubern


Prompt:
Complete this console code:

CERTIFICATE                EXPIRES                  RESIDUAL TIME   CERTIFICATE AUTHORITY   EXTERNALLY MANAGED
admin.conf                 Dec 30, 2020 23:36 UTC   364d                                    no
apiserver                  Dec 30, 2020 23:36 UTC   364d            ca                      no
apiserver-etcd-client      Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
apiserver-kubelet-client   Dec 30, 2020 23:36 UTC   364d            ca                      no
controller-manager.conf    Dec 30, 2020 23:36 UTC   364d                                    no
etcd-healthcheck-client    Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
etcd-peer                  Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no

Response:
etcd-server                Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
front-proxy-client         Dec 30, 2020 23:36 UTC   364d            front-proxy-ca          no
scheduler.conf             Dec 30, 2020 23:36 UTC   364d                                    no

CERTIFICATE AUTHORITY   EXPIRES                  RESIDUAL TIME   EXTERNALLY MANAGED
ca                      Dec 28, 2029 23:36 UTC   9y              no
etcd-ca                 Dec 28, 2029 23:36 UTC   9y              no
front-proxy-ca          Dec 28, 2029 23:36 UTC   9y              no

Context: Certificate Management with kubeadm | The command shows expiration/residual time for the client certificates in the /etc/kubernetes/pki folder and for the client certificate embedded in the kubeconfig files used by kubeadm (admin.conf, co


Prompt:
Explain this console code:

CERTIFICATE                EXPIRES                  RESIDUAL TIME   CERTIFICATE AUTHORITY   EXTERNALLY MANAGED
admin.conf                 Dec 30, 2020 23:36 UTC   364d                                    no
apiserver                  Dec 30, 2020 23:36 UTC   364d            ca                      no
apiserver-etcd-client      Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
apiserver-kubelet-client   Dec 30, 2020 23:36 UTC   364d            ca                      no
controller-manager.conf    Dec 30, 2020 23:36 UTC   364d                                    no
etcd-healthcheck-client    Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
etcd-peer                  Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
etcd-server                Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
front-proxy-client         Dec 30, 2020 23:36 UTC   364d            front-proxy-ca          no
scheduler.conf             Dec 30, 2020 23:36 UTC   364d                                    no

CERTIFICATE AUTHORITY   EXPIRES                  RESIDUAL TIME   EXTERNALLY MANAGED
ca                      Dec 28, 2029 23:36 UTC   9y              no
etcd-ca                 Dec 28, 2029 23:36 UTC   9y              no
front-proxy-ca          Dec 28, 2029 23:36 UTC   9y              no

Response: This console code Certificate Management with kubeadm | The command shows expiration/residual time for the client certificates in the /etc/kubernetes/pki folder and for the client certificate embedded in the kubeconfig files used by kubeadm (admin.conf, co


Prompt:
Explain this yaml code:

client-certificate: /var/lib/kubelet/pki/kubelet-client-current.pem
client-key: /var/lib/kubelet/pki/kubelet-client-current.pem

Response: This yaml code Certificate Management with kubeadm | kubeadm renews all the certificates during control plane upgrade.

Context: Certificate Management with kubeadm | kubeadm renews all the certificates during control plane upgrade.


Prompt:
Explain this shell code:

# If you are running cluster with a replicated control plane, this command
# needs to be executed on all the control-plane nodes.
kubeadm certs renew all

Response: This shell code Certificate Management with kubeadm | Clusters built with kubeadm often copy the admin.conf certificate into $HOME/.kube/config, as instructed in Creating a cluster with kubeadm. On such a system, to update the contents of $HOME/.kube/con

Context: Certificate Management with kubeadm | Clusters built with kubeadm often copy the admin.conf certificate into $HOME/.kube/config, as instructed in Creating a cluster with kubeadm. On such a system, to update the contents of $HOME/.kube/con


Prompt:
Explain this shell code:

sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

Response: This shell code Certificate Management with kubeadm | This section provides more details about how to execute manual certificate renewal using the Kubernetes certificates API.

Context: Certificate Management with kubeadm | This section provides more details about how to execute manual certificate renewal using the Kubernetes certificates API.


Prompt:
Complete this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
controllerManager:
  extraArgs:

Response:
  - name: "cluster-signing-cert-file"
    value: "/etc/kubernetes/pki/ca.crt"
  - name: "cluster-signing-key-file"
    value: "/etc/kubernetes/pki/ca.key"

Context: Certificate Management with kubeadm | See Create CertificateSigningRequest for creating CSRs with the Kubernetes API.


Prompt:
Explain this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
controllerManager:
  extraArgs:
  - name: "cluster-signing-cert-file"
    value: "/etc/kubernetes/pki/ca.crt"
  - name: "cluster-signing-key-file"
    value: "/etc/kubernetes/pki/ca.key"

Response: This yaml code Certificate Management with kubeadm | See Create CertificateSigningRequest for creating CSRs with the Kubernetes API.


Prompt:
Complete this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
---

Response:
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
serverTLSBootstrap: true

Context: Certificate Management with kubeadm | If you have already created the cluster you must adapt it by doing the following:


Prompt:
Explain this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
---
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
serverTLSBootstrap: true

Response: This yaml code Certificate Management with kubeadm | If you have already created the cluster you must adapt it by doing the following:


Prompt:
Explain this console code:

NAME        AGE     SIGNERNAME                        REQUESTOR                      CONDITION
csr-9wvgt   112s    kubernetes.io/kubelet-serving     system:node:worker-1           Pending
csr-lz97v   1m58s   kubernetes.io/kubelet-serving     system:node:control-plane-1    Pending

Response: This console code Certificate Management with kubeadm | To approve them you can do the following:

Context: Certificate Management with kubeadm | To approve them you can do the following:


Prompt:
Explain this text code:

Subject: O = system:masters, CN = kubernetes-super-admin

Response: This text code Certificate Management with kubeadm | You can use the kubeadm kubeconfig user command to generate kubeconfig files for additional users. The command accepts a mixture of command line flags and kubeadm configuration options. The generated

Context: Certificate Management with kubeadm | You can use the kubeadm kubeconfig user command to generate kubeconfig files for additional users. The command accepts a mixture of command line flags and kubeadm configuration options. The generated


Prompt:
Explain this text code:

Subject: O = kubeadm:cluster-admins, CN = kubernetes-admin

Response: This text code Certificate Management with kubeadm | You can use the kubeadm kubeconfig user command to generate kubeconfig files for additional users. The command accepts a mixture of command line flags and kubeadm configuration options. The generated


Prompt:
Complete this yaml code:

# example.yaml
apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
# Will be used as the target "cluster" in the kubeconfig

Response:
clusterName: "kubernetes"
# Will be used as the "server" (IP or DNS name) of this cluster in the kubeconfig
controlPlaneEndpoint: "some-dns-address:6443"
# The cluster CA key and certificate will be loaded from this local directory
certificatesDir: "/etc/kubernetes/pki"

Context: Certificate Management with kubeadm | Make sure that these settings match the desired target cluster settings. To see the settings of an existing cluster use:


Prompt:
Explain this yaml code:

# example.yaml
apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
# Will be used as the target "cluster" in the kubeconfig
clusterName: "kubernetes"
# Will be used as the "server" (IP or DNS name) of this cluster in the kubeconfig
controlPlaneEndpoint: "some-dns-address:6443"
# The cluster CA key and certificate will be loaded from this local directory
certificatesDir: "/etc/kubernetes/pki"

Response: This yaml code Certificate Management with kubeadm | Make sure that these settings match the desired target cluster settings. To see the settings of an existing cluster use:


Prompt:
Explain this shell code:

kubectl get cm kubeadm-config -n kube-system -o=jsonpath="{.data.ClusterConfiguration}"

Response: This shell code Certificate Management with kubeadm | The following example will generate a kubeconfig file with credentials valid for 24 hours for a new user johndoe that is part of the appdevs group:

Context: Certificate Management with kubeadm | The following example will generate a kubeconfig file with credentials valid for 24 hours for a new user johndoe that is part of the appdevs group:


Prompt:
Explain this shell code:

kubeadm kubeconfig user --config example.yaml --org appdevs --client-name johndoe --validity-period 24h

Response: This shell code Certificate Management with kubeadm | The following example will generate a kubeconfig file with administrator credentials valid for 1 week:

Context: Certificate Management with kubeadm | The following example will generate a kubeconfig file with administrator credentials valid for 1 week:


Prompt:
Explain this shell code:

kubeadm kubeconfig user --config example.yaml --client-name admin --validity-period 168h

Response: This shell code Certificate Management with kubeadm | You can create certificate signing requests with kubeadm certs generate-csr. Calling this command will generate .csr / .key file pairs for regular certificates. For certificates embedded in kubeconfig

Context: Certificate Management with kubeadm | You can create certificate signing requests with kubeadm certs generate-csr. Calling this command will generate .csr / .key file pairs for regular certificates. For certificates embedded in kubeconfig


Prompt:
Complete this shell code:

sudo kubeadm init phase certs ca
sudo kubeadm init phase certs etcd-ca

Response:
sudo kubeadm init phase certs front-proxy-ca
sudo kubeadm init phase certs sa

Context: Certificate Management with kubeadm | This will populate the folders /etc/kubernetes/pki and /etc/kubernetes/pki/etcd with all self-signed CA files (certificates and keys) and service account (public and private keys) that kubeadm needs f


Prompt:
Explain this shell code:

sudo kubeadm init phase certs ca
sudo kubeadm init phase certs etcd-ca
sudo kubeadm init phase certs front-proxy-ca
sudo kubeadm init phase certs sa

Response: This shell code Certificate Management with kubeadm | This will populate the folders /etc/kubernetes/pki and /etc/kubernetes/pki/etcd with all self-signed CA files (certificates and keys) and service account (public and private keys) that kubeadm needs f


Prompt:
Complete this bash code:

#!/bin/bash

# Set certificate expiration time in days
DAYS=365

# Process all CSR files except those for front-proxy and etcd
find ./ -name "*.csr" | grep -v "pki/etcd" | grep -v "front-proxy" | while read -r FILE;
do
    echo "* Processing ${FILE} ..."
    FILE=${FILE%.*} # Trim the extension
    if [ -f "./pki/ca.srl" ]; then
        SERIAL_FLAG="-CAserial ./pki/ca.srl"
    else
        SERIAL_FLAG="-CAcreateserial"
    fi
    openssl x509 -req -days "${DAYS}" -CA ./pki/ca.crt -CAkey ./pki/ca.key ${SERIAL_FLAG} \
        -in "${FILE}.csr" -out "${FILE}.crt"
    sleep 2
done

Response:
# Process all etcd CSRs
find ./pki/etcd -name "*.csr" | while read -r FILE;
do
    echo "* Processing ${FILE} ..."
    FILE=${FILE%.*} # Trim the extension
    if [ -f "./pki/etcd/ca.srl" ]; then
        SERIAL_FLAG=-CAserial ./pki/etcd/ca.srl
    else
        SERIAL_FLAG=-CAcreateserial
    fi
    openssl x509 -req -days "${DAYS}" -CA ./pki/etcd/ca.crt -CAkey ./pki/etcd/ca.key ${SERIAL_FLAG} \
        -in "${FILE}.csr" -out "${FILE}.crt"
done

# Process front-proxy CSRs
echo "* Processing ./pki/front-proxy-client.csr ..."
openssl x509 -req -days "${DAYS}" -CA ./pki/front-proxy-ca.crt -CAkey ./pki/front-proxy-ca.key -CAcreateserial \
    -in ./pki/front-proxy-client.csr -out ./pki/front-proxy-client.crt

Context: Certificate Management with kubeadm | Repeat this step for all nodes that have CSR files.


Prompt:
Explain this bash code:

#!/bin/bash

# Set certificate expiration time in days
DAYS=365

# Process all CSR files except those for front-proxy and etcd
find ./ -name "*.csr" | grep -v "pki/etcd" | grep -v "front-proxy" | while read -r FILE;
do
    echo "* Processing ${FILE} ..."
    FILE=${FILE%.*} # Trim the extension
    if [ -f "./pki/ca.srl" ]; then
        SERIAL_FLAG="-CAserial ./pki/ca.srl"
    else
        SERIAL_FLAG="-CAcreateserial"
    fi
    openssl x509 -req -days "${DAYS}" -CA ./pki/ca.crt -CAkey ./pki/ca.key ${SERIAL_FLAG} \
        -in "${FILE}.csr" -out "${FILE}.crt"
    sleep 2
done

# Process all etcd CSRs
find ./pki/etcd -name "*.csr" | while read -r FILE;
do
    echo "* Processing ${FILE} ..."
    FILE=${FILE%.*} # Trim the extension
    if [ -f "./pki/etcd/ca.srl" ]; then
        SERIAL_FLAG=-CAserial ./pki/etcd/ca.srl
    else
        SERIAL_FLAG=-CAcreateserial
    fi
    openssl x509 -req -days "${DAYS}" -CA ./pki/etcd/ca.crt -CAkey ./pki/etcd/ca.key ${SERIAL_FLAG} \
        -in "${FILE}.csr" -out "${FILE}.crt"
done

# Process front-proxy CSRs
echo "* Processing ./pki/front-proxy-client.csr ..."
openssl x509 -req -days "${DAYS}" -CA ./pki/front-proxy-ca.crt -CAkey ./pki/front-proxy-ca.key -CAcreateserial \
    -in ./pki/front-proxy-client.csr -out ./pki/front-proxy-client.crt

Response: This bash code Certificate Management with kubeadm | Repeat this step for all nodes that have CSR files.


Prompt:
Complete this bash code:

#!/bin/bash

CLUSTER=kubernetes
find ./ -name "*.conf" | while read -r FILE;
do

Response:
    echo "* Processing ${FILE} ..."
    KUBECONFIG="${FILE}" kubectl config set-cluster "${CLUSTER}" --certificate-authority ./pki/ca.crt --embed-certs
    USER=$(KUBECONFIG="${FILE}" kubectl config view -o jsonpath='{.users[0].name}')
    KUBECONFIG="${FILE}" kubectl config set-credentials "${USER}" --client-certificate "${FILE}.crt" --embed-certs
done

Context: Certificate Management with kubeadm | Perform this step on all nodes that have CSR files.


Prompt:
Explain this bash code:

#!/bin/bash

CLUSTER=kubernetes
find ./ -name "*.conf" | while read -r FILE;
do
    echo "* Processing ${FILE} ..."
    KUBECONFIG="${FILE}" kubectl config set-cluster "${CLUSTER}" --certificate-authority ./pki/ca.crt --embed-certs
    USER=$(KUBECONFIG="${FILE}" kubectl config view -o jsonpath='{.users[0].name}')
    KUBECONFIG="${FILE}" kubectl config set-credentials "${USER}" --client-certificate "${FILE}.crt" --embed-certs
done

Response: This bash code Certificate Management with kubeadm | Perform this step on all nodes that have CSR files.


Prompt:
Complete this bash code:

#!/bin/bash

# Cleanup CSR files

Response:
rm -f ./*.csr ./pki/*.csr ./pki/etcd/*.csr # Clean all CSR files

# Cleanup CRT files that were already embedded in kubeconfig files
rm -f ./*.crt

Context: Certificate Management with kubeadm | Optionally, move .srl files to the next node to be processed.


Prompt:
Explain this bash code:

#!/bin/bash

# Cleanup CSR files
rm -f ./*.csr ./pki/*.csr ./pki/etcd/*.csr # Clean all CSR files

# Cleanup CRT files that were already embedded in kubeconfig files
rm -f ./*.crt

Response: This bash code Certificate Management with kubeadm | Optionally, move .srl files to the next node to be processed.


Prompt:
Explain this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
encryptionAlgorithm: <ALGORITHM>

Response: This yaml code Certificate Management with kubeadm | <ALGORITHM> can be one of RSA-2048 (default), RSA-3072, RSA-4096 or ECDSA-P256.

Context: Certificate Management with kubeadm | <ALGORITHM> can be one of RSA-2048 (default), RSA-3072, RSA-4096 or ECDSA-P256.


Prompt:
Complete this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration

Response:
certificateValidityPeriod: 8760h # Default: 365 days × 24 hours = 1 year
caCertificateValidityPeriod: 87600h # Default: 365 days × 24 hours * 10 = 10 years

Context: Certificate Management with kubeadm | The values of the fields follow the accepted format for Go's time.Duration values, with the longest supported unit being h (hours).


Prompt:
Explain this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
certificateValidityPeriod: 8760h # Default: 365 days × 24 hours = 1 year
caCertificateValidityPeriod: 87600h # Default: 365 days × 24 hours * 10 = 10 years

Response: This yaml code Certificate Management with kubeadm | The values of the fields follow the accepted format for Go's time.Duration values, with the longest supported unit being h (hours).


Prompt:
Complete this text code:

CERTIFICATE                EXPIRES                  RESIDUAL TIME   CERTIFICATE AUTHORITY   EXTERNALLY MANAGED
admin.conf                 Dec 30, 2020 23:36 UTC   364d                                    no
apiserver                  Dec 30, 2020 23:36 UTC   364d            ca                      no
apiserver-etcd-client      Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
apiserver-kubelet-client   Dec 30, 2020 23:36 UTC   364d            ca                      no
controller-manager.conf    Dec 30, 2020 23:36 UTC   364d                                    no
etcd-healthcheck-client    Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
etcd-peer                  Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no

Response:
etcd-server                Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
front-proxy-client         Dec 30, 2020 23:36 UTC   364d            front-proxy-ca          no
scheduler.conf             Dec 30, 2020 23:36 UTC   364d                                    no

CERTIFICATE AUTHORITY   EXPIRES                  RESIDUAL TIME   EXTERNALLY MANAGED
ca                      Dec 28, 2029 23:36 UTC   9y              no
etcd-ca                 Dec 28, 2029 23:36 UTC   9y              no
front-proxy-ca          Dec 28, 2029 23:36 UTC   9y              no

Context: Certificate Management with kubeadm | The command shows expiration/residual time for the client certificates in the /etc/kubernetes/pki folder and for the client certificate embedded in the kubeconfig files used by kubeadm (admin.conf, co


Prompt:
Explain this text code:

CERTIFICATE                EXPIRES                  RESIDUAL TIME   CERTIFICATE AUTHORITY   EXTERNALLY MANAGED
admin.conf                 Dec 30, 2020 23:36 UTC   364d                                    no
apiserver                  Dec 30, 2020 23:36 UTC   364d            ca                      no
apiserver-etcd-client      Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
apiserver-kubelet-client   Dec 30, 2020 23:36 UTC   364d            ca                      no
controller-manager.conf    Dec 30, 2020 23:36 UTC   364d                                    no
etcd-healthcheck-client    Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
etcd-peer                  Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
etcd-server                Dec 30, 2020 23:36 UTC   364d            etcd-ca                 no
front-proxy-client         Dec 30, 2020 23:36 UTC   364d            front-proxy-ca          no
scheduler.conf             Dec 30, 2020 23:36 UTC   364d                                    no

CERTIFICATE AUTHORITY   EXPIRES                  RESIDUAL TIME   EXTERNALLY MANAGED
ca                      Dec 28, 2029 23:36 UTC   9y              no
etcd-ca                 Dec 28, 2029 23:36 UTC   9y              no
front-proxy-ca          Dec 28, 2029 23:36 UTC   9y              no

Response: This text code Certificate Management with kubeadm | The command shows expiration/residual time for the client certificates in the /etc/kubernetes/pki folder and for the client certificate embedded in the kubeconfig files used by kubeadm (admin.conf, co


Prompt:
Explain this text code:

client-certificate: /var/lib/kubelet/pki/kubelet-client-current.pem
client-key: /var/lib/kubelet/pki/kubelet-client-current.pem

Response: This text code Certificate Management with kubeadm | kubeadm renews all the certificates during control plane upgrade.

Context: Certificate Management with kubeadm | kubeadm renews all the certificates during control plane upgrade.


Prompt:
Explain this text code:

# If you are running cluster with a replicated control plane, this command
# needs to be executed on all the control-plane nodes.
kubeadm certs renew all

Response: This text code Certificate Management with kubeadm | Clusters built with kubeadm often copy the admin.conf certificate into $HOME/.kube/config, as instructed in Creating a cluster with kubeadm. On such a system, to update the contents of $HOME/.kube/con

Context: Certificate Management with kubeadm | Clusters built with kubeadm often copy the admin.conf certificate into $HOME/.kube/config, as instructed in Creating a cluster with kubeadm. On such a system, to update the contents of $HOME/.kube/con


Prompt:
Explain this text code:

sudo cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
sudo chown $(id -u):$(id -g) $HOME/.kube/config

Response: This text code Certificate Management with kubeadm | This section provides more details about how to execute manual certificate renewal using the Kubernetes certificates API.

Context: Certificate Management with kubeadm | This section provides more details about how to execute manual certificate renewal using the Kubernetes certificates API.


Prompt:
Complete this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
controllerManager:
  extraArgs:

Response:
  - name: "cluster-signing-cert-file"
    value: "/etc/kubernetes/pki/ca.crt"
  - name: "cluster-signing-key-file"
    value: "/etc/kubernetes/pki/ca.key"

Context: Certificate Management with kubeadm | See Create CertificateSigningRequest for creating CSRs with the Kubernetes API.


Prompt:
Explain this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
controllerManager:
  extraArgs:
  - name: "cluster-signing-cert-file"
    value: "/etc/kubernetes/pki/ca.crt"
  - name: "cluster-signing-key-file"
    value: "/etc/kubernetes/pki/ca.key"

Response: This yaml code Certificate Management with kubeadm | See Create CertificateSigningRequest for creating CSRs with the Kubernetes API.


Prompt:
Complete this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
---

Response:
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
serverTLSBootstrap: true

Context: Certificate Management with kubeadm | If you have already created the cluster you must adapt it by doing the following:


Prompt:
Explain this yaml code:

apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
---
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
serverTLSBootstrap: true

Response: This yaml code Certificate Management with kubeadm | If you have already created the cluster you must adapt it by doing the following:


Prompt:
Explain this text code:

NAME        AGE     SIGNERNAME                        REQUESTOR                      CONDITION
csr-9wvgt   112s    kubernetes.io/kubelet-serving     system:node:worker-1           Pending
csr-lz97v   1m58s   kubernetes.io/kubelet-serving     system:node:control-plane-1    Pending

Response: This text code Certificate Management with kubeadm | To approve them you can do the following:

Context: Certificate Management with kubeadm | To approve them you can do the following:


Prompt:
Complete this yaml code:

# example.yaml
apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
# Will be used as the target "cluster" in the kubeconfig

Response:
clusterName: "kubernetes"
# Will be used as the "server" (IP or DNS name) of this cluster in the kubeconfig
controlPlaneEndpoint: "some-dns-address:6443"
# The cluster CA key and certificate will be loaded from this local directory
certificatesDir: "/etc/kubernetes/pki"

Context: Certificate Management with kubeadm | Make sure that these settings match the desired target cluster settings. To see the settings of an existing cluster use:


Prompt:
Explain this yaml code:

# example.yaml
apiVersion: kubeadm.k8s.io/v1beta4
kind: ClusterConfiguration
# Will be used as the target "cluster" in the kubeconfig
clusterName: "kubernetes"
# Will be used as the "server" (IP or DNS name) of this cluster in the kubeconfig
controlPlaneEndpoint: "some-dns-address:6443"
# The cluster CA key and certificate will be loaded from this local directory
certificatesDir: "/etc/kubernetes/pki"

Response: This yaml code Certificate Management with kubeadm | Make sure that these settings match the desired target cluster settings. To see the settings of an existing cluster use:


Prompt:
Explain this bash code:

kubectl get cm kubeadm-config -n kube-system -o=jsonpath="{.data.ClusterConfiguration}"

Response: This bash code Certificate Management with kubeadm | The following example will generate a kubeconfig file with credentials valid for 24 hours for a new user johndoe that is part of the appdevs group:

Context: Certificate Management with kubeadm | The following example will generate a kubeconfig file with credentials valid for 24 hours for a new user johndoe that is part of the appdevs group:


Prompt:
Explain this text code:

kubeadm kubeconfig user --config example.yaml --org appdevs --client-name johndoe --validity-period 24h

Response: This text code Certificate Management with kubeadm | The following example will generate a kubeconfig file with administrator credentials valid for 1 week:

Context: Certificate Management with kubeadm | The following example will generate a kubeconfig file with administrator credentials valid for 1 week:


Prompt:
Explain this text code:

kubeadm kubeconfig user --config example.yaml --client-name admin --validity-period 168h

Response: This text code Certificate Management with kubeadm | You can create certificate signing requests with kubeadm certs generate-csr. Calling this command will generate .csr / .key file pairs for regular certificates. For certificates embedded in kubeconfig

Context: Certificate Management with kubeadm | You can create certificate signing requests with kubeadm certs generate-csr. Calling this command will generate .csr / .key file pairs for regular certificates. For certificates embedded in kubeconfig


Prompt:
Complete this text code:

sudo kubeadm init phase certs ca
sudo kubeadm init phase certs etcd-ca

Response:
sudo kubeadm init phase certs front-proxy-ca
sudo kubeadm init phase certs sa

Context: Certificate Management with kubeadm | This will populate the folders /etc/kubernetes/pki and /etc/kubernetes/pki/etcd with all self-signed CA files (certificates and keys) and service account (public and private keys) that kubeadm needs f


Prompt:
Explain this text code:

sudo kubeadm init phase certs ca
sudo kubeadm init phase certs etcd-ca
sudo kubeadm init phase certs front-proxy-ca
sudo kubeadm init phase certs sa

Response: This text code Certificate Management with kubeadm | This will populate the folders /etc/kubernetes/pki and /etc/kubernetes/pki/etcd with all self-signed CA files (certificates and keys) and service account (public and private keys) that kubeadm needs f


Prompt:
Complete this text code:

#!/bin/bash

# Set certificate expiration time in days
DAYS=365

# Process all CSR files except those for front-proxy and etcd
find ./ -name "*.csr" | grep -v "pki/etcd" | grep -v "front-proxy" | while read -r FILE;
do
    echo "* Processing ${FILE} ..."
    FILE=${FILE%.*} # Trim the extension
    if [ -f "./pki/ca.srl" ]; then
        SERIAL_FLAG="-CAserial ./pki/ca.srl"
    else
        SERIAL_FLAG="-CAcreateserial"
    fi
    openssl x509 -req -days "${DAYS}" -CA ./pki/ca.crt -CAkey ./pki/ca.key ${SERIAL_FLAG} \
        -in "${FILE}.csr" -out "${FILE}.crt"
    sleep 2
done

Response:
# Process all etcd CSRs
find ./pki/etcd -name "*.csr" | while read -r FILE;
do
    echo "* Processing ${FILE} ..."
    FILE=${FILE%.*} # Trim the extension
    if [ -f "./pki/etcd/ca.srl" ]; then
        SERIAL_FLAG=-CAserial ./pki/etcd/ca.srl
    else
        SERIAL_FLAG=-CAcreateserial
    fi
    openssl x509 -req -days "${DAYS}" -CA ./pki/etcd/ca.crt -CAkey ./pki/etcd/ca.key ${SERIAL_FLAG} \
        -in "${FILE}.csr" -out "${FILE}.crt"
done

# Process front-proxy CSRs
echo "* Processing ./pki/front-proxy-client.csr ..."
openssl x509 -req -days "${DAYS}" -CA ./pki/front-proxy-ca.crt -CAkey ./pki/front-proxy-ca.key -CAcreateserial \
    -in ./pki/front-proxy-client.csr -out ./pki/front-proxy-client.crt

Context: Certificate Management with kubeadm | Repeat this step for all nodes that have CSR files.


Prompt:
Explain this text code:

#!/bin/bash

# Set certificate expiration time in days
DAYS=365

# Process all CSR files except those for front-proxy and etcd
find ./ -name "*.csr" | grep -v "pki/etcd" | grep -v "front-proxy" | while read -r FILE;
do
    echo "* Processing ${FILE} ..."
    FILE=${FILE%.*} # Trim the extension
    if [ -f "./pki/ca.srl" ]; then
        SERIAL_FLAG="-CAserial ./pki/ca.srl"
    else
        SERIAL_FLAG="-CAcreateserial"
    fi
    openssl x509 -req -days "${DAYS}" -CA ./pki/ca.crt -CAkey ./pki/ca.key ${SERIAL_FLAG} \
        -in "${FILE}.csr" -out "${FILE}.crt"
    sleep 2
done

# Process all etcd CSRs
find ./pki/etcd -name "*.csr" | while read -r FILE;
do
    echo "* Processing ${FILE} ..."
    FILE=${FILE%.*} # Trim the extension
    if [ -f "./pki/etcd/ca.srl" ]; then
        SERIAL_FLAG=-CAserial ./pki/etcd/ca.srl
    else
        SERIAL_FLAG=-CAcreateserial
    fi
    openssl x509 -req -days "${DAYS}" -CA ./pki/etcd/ca.crt -CAkey ./pki/etcd/ca.key ${SERIAL_FLAG} \
        -in "${FILE}.csr" -out "${FILE}.crt"
done

# Process front-proxy CSRs
echo "* Processing ./pki/front-proxy-client.csr ..."
openssl x509 -req -days "${DAYS}" -CA ./pki/front-proxy-ca.crt -CAkey ./pki/front-proxy-ca.key -CAcreateserial \
    -in ./pki/front-proxy-client.csr -out ./pki/front-proxy-client.crt

Response: This text code Certificate Management with kubeadm | Repeat this step for all nodes that have CSR files.


Prompt:
Complete this text code:

#!/bin/bash

CLUSTER=kubernetes
find ./ -name "*.conf" | while read -r FILE;
do

Response:
    echo "* Processing ${FILE} ..."
    KUBECONFIG="${FILE}" kubectl config set-cluster "${CLUSTER}" --certificate-authority ./pki/ca.crt --embed-certs
    USER=$(KUBECONFIG="${FILE}" kubectl config view -o jsonpath='{.users[0].name}')
    KUBECONFIG="${FILE}" kubectl config set-credentials "${USER}" --client-certificate "${FILE}.crt" --embed-certs
done

Context: Certificate Management with kubeadm | Perform this step on all nodes that have CSR files.


Prompt:
Explain this text code:

#!/bin/bash

CLUSTER=kubernetes
find ./ -name "*.conf" | while read -r FILE;
do
    echo "* Processing ${FILE} ..."
    KUBECONFIG="${FILE}" kubectl config set-cluster "${CLUSTER}" --certificate-authority ./pki/ca.crt --embed-certs
    USER=$(KUBECONFIG="${FILE}" kubectl config view -o jsonpath='{.users[0].name}')
    KUBECONFIG="${FILE}" kubectl config set-credentials "${USER}" --client-certificate "${FILE}.crt" --embed-certs
done

Response: This text code Certificate Management with kubeadm | Perform this step on all nodes that have CSR files.


Prompt:
Complete this text code:

#!/bin/bash

# Cleanup CSR files

Response:
rm -f ./*.csr ./pki/*.csr ./pki/etcd/*.csr # Clean all CSR files

# Cleanup CRT files that were already embedded in kubeconfig files
rm -f ./*.crt

Context: Certificate Management with kubeadm | Optionally, move .srl files to the next node to be processed.


Prompt:
Explain this text code:

#!/bin/bash

# Cleanup CSR files
rm -f ./*.csr ./pki/*.csr ./pki/etcd/*.csr # Clean all CSR files

# Cleanup CRT files that were already embedded in kubeconfig files
rm -f ./*.crt

Response: This text code Certificate Management with kubeadm | Optionally, move .srl files to the next node to be processed.


Prompt:
Complete this yaml code:

cat << EOF > /etc/systemd/system/kubelet.service.d/kubelet.conf
# Replace "systemd" with the cgroup driver of your container runtime. The default value in the kubelet is "cgroupfs".
# Replace the value of "containerRuntimeEndpoint" for a different container runtime if needed.
#
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
authentication:
  anonymous:
    enabled: false
  webhook:
    enabled: false
authorization:
  mode: AlwaysAllow
cgroupDriver: systemd

Response:
address: 127.0.0.1
containerRuntimeEndpoint: unix:///var/run/containerd/containerd.sock
staticPodPath: /etc/kubernetes/manifests
EOF

cat << EOF > /etc/systemd/system/kubelet.service.d/20-etcd-service-manager.conf
[Service]
ExecStart=
ExecStart=/usr/bin/kubelet --config=/etc/systemd/system/kubelet.service.d/kubelet.conf
Restart=always
EOF

systemctl daemon-reload
systemctl restart kubelet

Context: Set up a High Availability etcd Cluster with kubeadm | Check the kubelet status to ensure it is running.


Prompt:
Explain this yaml code:

cat << EOF > /etc/systemd/system/kubelet.service.d/kubelet.conf
# Replace "systemd" with the cgroup driver of your container runtime. The default value in the kubelet is "cgroupfs".
# Replace the value of "containerRuntimeEndpoint" for a different container runtime if needed.
#
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
authentication:
  anonymous:
    enabled: false
  webhook:
    enabled: false
authorization:
  mode: AlwaysAllow
cgroupDriver: systemd
address: 127.0.0.1
containerRuntimeEndpoint: unix:///var/run/containerd/containerd.sock
staticPodPath: /etc/kubernetes/manifests
EOF

cat << EOF > /etc/systemd/system/kubelet.service.d/20-etcd-service-manager.conf
[Service]
ExecStart=
ExecStart=/usr/bin/kubelet --config=/etc/systemd/system/kubelet.service.d/kubelet.conf
Restart=always
EOF

systemctl daemon-reload
systemctl restart kubelet

Response: This yaml code Set up a High Availability etcd Cluster with kubeadm | Check the kubelet status to ensure it is running.


Prompt:
Complete this yaml code:

# Update HOST0, HOST1 and HOST2 with the IPs of your hosts
export HOST0=10.0.0.6
export HOST1=10.0.0.7
export HOST2=10.0.0.8

# Update NAME0, NAME1 and NAME2 with the hostnames of your hosts
export NAME0="infra0"
export NAME1="infra1"
export NAME2="infra2"

# Create temp directories to store files that will end up on other hosts
mkdir -p /tmp/${HOST0}/ /tmp/${HOST1}/ /tmp/${HOST2}/

HOSTS=(${HOST0} ${HOST1} ${HOST2})
NAMES=(${NAME0} ${NAME1} ${NAME2})

for i in "${!HOSTS[@]}"; do
HOST=${HOSTS[$i]}
NAME=${NAMES[$i]}
cat << EOF > /tmp/${HOST}/kubeadmcfg.yaml
---
apiVersion: "kubeadm.k8s.io/v1beta4"
kind: InitConfiguration
nodeRegistration:
    name: ${NAME}
localAPIEndpoint:

Response:
    advertiseAddress: ${HOST}
---
apiVersion: "kubeadm.k8s.io/v1beta4"
kind: ClusterConfiguration
etcd:
    local:
        serverCertSANs:
        - "${HOST}"
        peerCertSANs:
        - "${HOST}"
        extraArgs:
        - name: initial-cluster
          value: ${NAMES[0]}=https://${HOSTS[0]}:2380,${NAMES[1]}=https://${HOSTS[1]}:2380,${NAMES[2]}=https://${HOSTS[2]}:2380
        - name: initial-cluster-state
          value: new
        - name: name
          value: ${NAME}
        - name: listen-peer-urls
          value: https://${HOST}:2380
        - name: listen-client-urls
          value: https://${HOST}:2379
        - name: advertise-client-urls
          value: https://${HOST}:2379
        - name: initial-advertise-peer-urls
          value: https://${HOST}:2380
EOF
done

Context: Set up a High Availability etcd Cluster with kubeadm | Generate the certificate authority.


Prompt:
Explain this yaml code:

# Update HOST0, HOST1 and HOST2 with the IPs of your hosts
export HOST0=10.0.0.6
export HOST1=10.0.0.7
export HOST2=10.0.0.8

# Update NAME0, NAME1 and NAME2 with the hostnames of your hosts
export NAME0="infra0"
export NAME1="infra1"
export NAME2="infra2"

# Create temp directories to store files that will end up on other hosts
mkdir -p /tmp/${HOST0}/ /tmp/${HOST1}/ /tmp/${HOST2}/

HOSTS=(${HOST0} ${HOST1} ${HOST2})
NAMES=(${NAME0} ${NAME1} ${NAME2})

for i in "${!HOSTS[@]}"; do
HOST=${HOSTS[$i]}
NAME=${NAMES[$i]}
cat << EOF > /tmp/${HOST}/kubeadmcfg.yaml
---
apiVersion: "kubeadm.k8s.io/v1beta4"
kind: InitConfiguration
nodeRegistration:
    name: ${NAME}
localAPIEndpoint:
    advertiseAddress: ${HOST}
---
apiVersion: "kubeadm.k8s.io/v1beta4"
kind: ClusterConfiguration
etcd:
    local:
        serverCertSANs:
        - "${HOST}"
        peerCertSANs:
        - "${HOST}"
        extraArgs:
        - name: initial-cluster
          value: ${NAMES[0]}=https://${HOSTS[0]}:2380,${NAMES[1]}=https://${HOSTS[1]}:2380,${NAMES[2]}=https://${HOSTS[2]}:2380
        - name: initial-cluster-state
          value: new
        - name: name
          value: ${NAME}
        - name: listen-peer-urls
          value: https://${HOST}:2380
        - name: listen-client-urls
          value: https://${HOST}:2379
        - name: advertise-client-urls
          value: https://${HOST}:2379
        - name: initial-advertise-peer-urls
          value: https://${HOST}:2380
EOF
done

Response: This yaml code Set up a High Availability etcd Cluster with kubeadm | Generate the certificate authority.


Prompt:
Complete this text code:

kubeadm init phase certs etcd-server --config=/tmp/${HOST2}/kubeadmcfg.yaml
kubeadm init phase certs etcd-peer --config=/tmp/${HOST2}/kubeadmcfg.yaml
kubeadm init phase certs etcd-healthcheck-client --config=/tmp/${HOST2}/kubeadmcfg.yaml
kubeadm init phase certs apiserver-etcd-client --config=/tmp/${HOST2}/kubeadmcfg.yaml
cp -R /etc/kubernetes/pki /tmp/${HOST2}/
# cleanup non-reusable certificates
find /etc/kubernetes/pki -not -name ca.crt -not -name ca.key -type f -delete

kubeadm init phase certs etcd-server --config=/tmp/${HOST1}/kubeadmcfg.yaml
kubeadm init phase certs etcd-peer --config=/tmp/${HOST1}/kubeadmcfg.yaml
kubeadm init phase certs etcd-healthcheck-client --config=/tmp/${HOST1}/kubeadmcfg.yaml
kubeadm init phase certs apiserver-etcd-client --config=/tmp/${HOST1}/kubeadmcfg.yaml

Response:
cp -R /etc/kubernetes/pki /tmp/${HOST1}/
find /etc/kubernetes/pki -not -name ca.crt -not -name ca.key -type f -delete

kubeadm init phase certs etcd-server --config=/tmp/${HOST0}/kubeadmcfg.yaml
kubeadm init phase certs etcd-peer --config=/tmp/${HOST0}/kubeadmcfg.yaml
kubeadm init phase certs etcd-healthcheck-client --config=/tmp/${HOST0}/kubeadmcfg.yaml
kubeadm init phase certs apiserver-etcd-client --config=/tmp/${HOST0}/kubeadmcfg.yaml
# No need to move the certs because they are for HOST0

# clean up certs that should not be copied off this host
find /tmp/${HOST2} -name ca.key -type f -delete
find /tmp/${HOST1} -name ca.key -type f -delete

Context: Set up a High Availability etcd Cluster with kubeadm | Copy certificates and kubeadm configs.


Prompt:
Explain this text code:

kubeadm init phase certs etcd-server --config=/tmp/${HOST2}/kubeadmcfg.yaml
kubeadm init phase certs etcd-peer --config=/tmp/${HOST2}/kubeadmcfg.yaml
kubeadm init phase certs etcd-healthcheck-client --config=/tmp/${HOST2}/kubeadmcfg.yaml
kubeadm init phase certs apiserver-etcd-client --config=/tmp/${HOST2}/kubeadmcfg.yaml
cp -R /etc/kubernetes/pki /tmp/${HOST2}/
# cleanup non-reusable certificates
find /etc/kubernetes/pki -not -name ca.crt -not -name ca.key -type f -delete

kubeadm init phase certs etcd-server --config=/tmp/${HOST1}/kubeadmcfg.yaml
kubeadm init phase certs etcd-peer --config=/tmp/${HOST1}/kubeadmcfg.yaml
kubeadm init phase certs etcd-healthcheck-client --config=/tmp/${HOST1}/kubeadmcfg.yaml
kubeadm init phase certs apiserver-etcd-client --config=/tmp/${HOST1}/kubeadmcfg.yaml
cp -R /etc/kubernetes/pki /tmp/${HOST1}/
find /etc/kubernetes/pki -not -name ca.crt -not -name ca.key -type f -delete

kubeadm init phase certs etcd-server --config=/tmp/${HOST0}/kubeadmcfg.yaml
kubeadm init phase certs etcd-peer --config=/tmp/${HOST0}/kubeadmcfg.yaml
kubeadm init phase certs etcd-healthcheck-client --config=/tmp/${HOST0}/kubeadmcfg.yaml
kubeadm init phase certs apiserver-etcd-client --config=/tmp/${HOST0}/kubeadmcfg.yaml
# No need to move the certs because they are for HOST0

# clean up certs that should not be copied off this host
find /tmp/${HOST2} -name ca.key -type f -delete
find /tmp/${HOST1} -name ca.key -type f -delete

Response: This text code Set up a High Availability etcd Cluster with kubeadm | Copy certificates and kubeadm configs.


Prompt:
Complete this text code:

USER=ubuntu
HOST=${HOST1}
scp -r /tmp/${HOST}/* ${USER}@${HOST}:

Response:
ssh ${USER}@${HOST}
USER@HOST $ sudo -Es
root@HOST $ chown -R root:root pki
root@HOST $ mv pki /etc/kubernetes/

Context: Set up a High Availability etcd Cluster with kubeadm | Ensure all expected files exist.


Prompt:
Explain this text code:

USER=ubuntu
HOST=${HOST1}
scp -r /tmp/${HOST}/* ${USER}@${HOST}:
ssh ${USER}@${HOST}
USER@HOST $ sudo -Es
root@HOST $ chown -R root:root pki
root@HOST $ mv pki /etc/kubernetes/

Response: This text code Set up a High Availability etcd Cluster with kubeadm | Ensure all expected files exist.


Prompt:
Complete this text code:

/tmp/${HOST0}
└── kubeadmcfg.yaml
---
/etc/kubernetes/pki
├── apiserver-etcd-client.crt
├── apiserver-etcd-client.key
└── etcd

Response:
    ├── ca.crt
    ├── ca.key
    ├── healthcheck-client.crt
    ├── healthcheck-client.key
    ├── peer.crt
    ├── peer.key
    ├── server.crt
    └── server.key

Context: Set up a High Availability etcd Cluster with kubeadm | On $HOST1:


Prompt:
Explain this text code:

/tmp/${HOST0}
└── kubeadmcfg.yaml
---
/etc/kubernetes/pki
├── apiserver-etcd-client.crt
├── apiserver-etcd-client.key
└── etcd
    ├── ca.crt
    ├── ca.key
    ├── healthcheck-client.crt
    ├── healthcheck-client.key
    ├── peer.crt
    ├── peer.key
    ├── server.crt
    └── server.key

Response: This text code Set up a High Availability etcd Cluster with kubeadm | On $HOST1:


Prompt:
Complete this text code:

$HOME
└── kubeadmcfg.yaml
---
/etc/kubernetes/pki
├── apiserver-etcd-client.crt
├── apiserver-etcd-client.key
└── etcd

Response:
    ├── ca.crt
    ├── healthcheck-client.crt
    ├── healthcheck-client.key
    ├── peer.crt
    ├── peer.key
    ├── server.crt
    └── server.key

Context: Set up a High Availability etcd Cluster with kubeadm | On $HOST2:


Prompt:
Explain this text code:

$HOME
└── kubeadmcfg.yaml
---
/etc/kubernetes/pki
├── apiserver-etcd-client.crt
├── apiserver-etcd-client.key
└── etcd
    ├── ca.crt
    ├── healthcheck-client.crt
    ├── healthcheck-client.key
    ├── peer.crt
    ├── peer.key
    ├── server.crt
    └── server.key

Response: This text code Set up a High Availability etcd Cluster with kubeadm | On $HOST2:


Prompt:
Complete this text code:

$HOME
└── kubeadmcfg.yaml
---
/etc/kubernetes/pki
├── apiserver-etcd-client.crt
├── apiserver-etcd-client.key
└── etcd

Response:
    ├── ca.crt
    ├── healthcheck-client.crt
    ├── healthcheck-client.key
    ├── peer.crt
    ├── peer.key
    ├── server.crt
    └── server.key

Context: Set up a High Availability etcd Cluster with kubeadm | Create the static pod manifests.


Prompt:
Explain this text code:

$HOME
└── kubeadmcfg.yaml
---
/etc/kubernetes/pki
├── apiserver-etcd-client.crt
├── apiserver-etcd-client.key
└── etcd
    ├── ca.crt
    ├── healthcheck-client.crt
    ├── healthcheck-client.key
    ├── peer.crt
    ├── peer.key
    ├── server.crt
    └── server.key

Response: This text code Set up a High Availability etcd Cluster with kubeadm | Create the static pod manifests.


Prompt:
Explain this text code:

root@HOST0 $ kubeadm init phase etcd local --config=/tmp/${HOST0}/kubeadmcfg.yaml
root@HOST1 $ kubeadm init phase etcd local --config=$HOME/kubeadmcfg.yaml
root@HOST2 $ kubeadm init phase etcd local --config=$HOME/kubeadmcfg.yaml

Response: This text code Set up a High Availability etcd Cluster with kubeadm | Optional: Check the cluster health.

Context: Set up a High Availability etcd Cluster with kubeadm | Optional: Check the cluster health.


Prompt:
Complete this text code:

ETCDCTL_API=3 etcdctl \
--cert /etc/kubernetes/pki/etcd/peer.crt \
--key /etc/kubernetes/pki/etcd/peer.key \
--cacert /etc/kubernetes/pki/etcd/ca.crt \

Response:
--endpoints https://${HOST0}:2379 endpoint health
...
https://[HOST0 IP]:2379 is healthy: successfully committed proposal: took = 16.283339ms
https://[HOST1 IP]:2379 is healthy: successfully committed proposal: took = 19.44402ms
https://[HOST2 IP]:2379 is healthy: successfully committed proposal: took = 35.926451ms

Context: Set up a High Availability etcd Cluster with kubeadm | Once you have an etcd cluster with 3 working members, you can continue setting up a highly available control plane using the external etcd method with kubeadm.


Prompt:
Explain this text code:

ETCDCTL_API=3 etcdctl \
--cert /etc/kubernetes/pki/etcd/peer.crt \
--key /etc/kubernetes/pki/etcd/peer.key \
--cacert /etc/kubernetes/pki/etcd/ca.crt \
--endpoints https://${HOST0}:2379 endpoint health
...
https://[HOST0 IP]:2379 is healthy: successfully committed proposal: took = 16.283339ms
https://[HOST1 IP]:2379 is healthy: successfully committed proposal: took = 19.44402ms
https://[HOST2 IP]:2379 is healthy: successfully committed proposal: took = 35.926451ms

Response: This text code Set up a High Availability etcd Cluster with kubeadm | Once you have an etcd cluster with 3 working members, you can continue setting up a highly available control plane using the external etcd method with kubeadm.


Prompt:
Complete this sh code:

cat << EOF > /etc/systemd/system/kubelet.service.d/kubelet.conf
# Replace "systemd" with the cgroup driver of your container runtime. The default value in the kubelet is "cgroupfs".
# Replace the value of "containerRuntimeEndpoint" for a different container runtime if needed.
#
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
authentication:
  anonymous:
    enabled: false
  webhook:
    enabled: false
authorization:
  mode: AlwaysAllow
cgroupDriver: systemd

Response:
address: 127.0.0.1
containerRuntimeEndpoint: unix:///var/run/containerd/containerd.sock
staticPodPath: /etc/kubernetes/manifests
EOF

cat << EOF > /etc/systemd/system/kubelet.service.d/20-etcd-service-manager.conf
[Service]
ExecStart=
ExecStart=/usr/bin/kubelet --config=/etc/systemd/system/kubelet.service.d/kubelet.conf
Restart=always
EOF

systemctl daemon-reload
systemctl restart kubelet


Prompt:
Explain this sh code:

cat << EOF > /etc/systemd/system/kubelet.service.d/kubelet.conf
# Replace "systemd" with the cgroup driver of your container runtime. The default value in the kubelet is "cgroupfs".
# Replace the value of "containerRuntimeEndpoint" for a different container runtime if needed.
#
apiVersion: kubelet.config.k8s.io/v1beta1
kind: KubeletConfiguration
authentication:
  anonymous:
    enabled: false
  webhook:
    enabled: false
authorization:
  mode: AlwaysAllow
cgroupDriver: systemd
address: 127.0.0.1
containerRuntimeEndpoint: unix:///var/run/containerd/containerd.sock
staticPodPath: /etc/kubernetes/manifests
EOF

cat << EOF > /etc/systemd/system/kubelet.service.d/20-etcd-service-manager.conf
[Service]
ExecStart=
ExecStart=/usr/bin/kubelet --config=/etc/systemd/system/kubelet.service.d/kubelet.conf
Restart=always
EOF

systemctl daemon-reload
systemctl restart kubelet

Response: This sh code Set up a High Availability etcd Cluster with kubeadm | Check the kubelet status to ensure it is running.