Kubernetes Documentation¶

kind create/delete cluster [flags] 

--config string           path to a kind config file

-h, --help                help for cluster

--image string            node docker image to use for booting the cluster

-n, --name string         cluster name, overrides KIND_CLUSTER_NAME (default kind)

--retain                  retain nodes for debugging when cluster creation fails

--wait duration           wait for control plane node to be ready (default 0s) 

kind create cluster --name <ibtisam>            # Ensuring node image (kindest/node:v1.30.0) 
kind create cluster --name <ibtisam> --image <abc>
kind create cluster --config /path/to/file
kind get clusters/nodes/kubeconfig
kind delete cluster --name ibtisam  # Delete to recreate; no restart command.

systemctl stop docker; systemctl stop docker.socket; systemctl --user stop docker-desktop
lsmod | grep kvm; sudo modprobe -r kvm kvm_intel; sudo reboot

minikube start --driver virtualbox
minikube start --driver docker 

minikube status/start/stop/delete/dashboard/pause/unpause 

minikube addons enable metrics-server   # for minikube  
# only one Metrics Server for one cluster whether minikube or other. 
kubectl apply -f https://github.com/kubernetes-sigs/metrics-server/releases/latest/download/components.yaml # install Metrics-server    
kubectl patch -n kube-system deployment metrics-server --type=json -p '[{"op":"add","path":"/spec/template/spec/containers/0/args/-","value":"--kubelet-insecure-tls"}]'

kubectl config get-contexts # to get all available clusters 
kubectl config get-clusters     
kubectl cluster-info
kubectl config use-context <minikube>   # use, not set          
kubectl config use-context <kind-ibtisam>
kubectl config current-context                              
kubectl cluster-info --context $(kubectl config current-context)
kubectl config view
kubectl config delete-context kind-ibtisam                  
kubectl config delete-cluster kind-ibtisam
kubectl config set-context <context-name> --cluster=<cluster-name> --user=<user-name> --namespace=<namespace>

curl -LO "https://dl.k8s.io/release/$(curl -L -s https://dl.k8s.io/release/stable.txt)/bin/linux/amd64/kubectl"
kubectl version
kubectl version --client false -o yaml

Basic Commands (Beginner):
  create          Create a resource from a file or from stdin
  expose          Take a replication controller, service, deployment or pod and expose it as a new Kubernetes service
  run             Run a particular image on the cluster
  set             Set specific features on objects

Basic Commands (Intermediate):
  explain         Get documentation for a resource
  get             Display one or many resources
  edit            Edit a resource on the server
  delete          Delete resources by file names, stdin, resources and names, or by resources and label selector

Deploy Commands:
  rollout         Manage the rollout of a resource
  scale           Set a new size for a deployment, replica set, or replication controller       --replicas=0
  autoscale       Auto-scale a deployment, replica set, stateful set, or replication controller

Cluster Management Commands:
  certificate     Modify certificate resources
  cluster-info    Display cluster information
  top             Display resource (CPU/memory) usage
  cordon          Mark node as unschedulable
  uncordon        Mark node as schedulable
  drain           Drain node in preparation for maintenance
  taint           Update the taints on one or more nodes

Troubleshooting and Debugging Commands:
  describe        Show details of a specific resource or group of resources
  logs            Print the logs for a container in a pod
  attach          Attach to a running container
  exec            Execute a command in a container
  port-forward    Forward one or more local ports to a pod
  proxy           Run a proxy to the Kubernetes API server
  cp              Copy files and directories to and from containers
  auth            Inspect authorization
  debug           Create debugging sessions for troubleshooting workloads and nodes
  events          List events

Advanced Commands:
  diff            Diff the live version against a would-be applied version
  apply           Apply a configuration to a resource by file name or stdin
  patch           Update fields of a resource
  replace         Replace a resource by file name or stdin
  wait            Experimental: Wait for a specific condition on one or many resources
  kustomize       Build a kustomization target from a directory or URL

Settings Commands:
  label           Update the labels on a resource
  annotate        Update the annotations on a resource
  completion      Output shell completion code for the specified shell (bash, zsh, fish, or powershell)

Other Commands:
  api-resources   Print the supported API resources on the server
  api-versions    Print the supported API versions on the server, in the form of "group/version"
  config          Modify kubeconfig files
  plugin          Provides utilities for interacting with plugins
  version         Print the client and server version information

current-context   Display the current-context
delete-cluster    Delete the specified cluster from the kubeconfig
delete-context    Delete the specified context from the kubeconfig
delete-user       Delete the specified user from the kubeconfig
get-clusters      Display clusters defined in the kubeconfig
get-contexts      Describe one or many contexts
get-users         Display users defined in the kubeconfig
rename-context    Rename a context from the kubeconfig file
set               Set an individual value in a kubeconfig file
set-cluster       Set a cluster entry in kubeconfig
set-context       Set a context entry in kubeconfig
set-credentials   Set a user entry in kubeconfig
unset             Unset an individual value in a kubeconfig file
use-context       Set the current-context in a kubeconfig file
view              Display merged kubeconfig settings or a specified kubeconfig file

-f, --filename=[]                # Filename, directory, or URL to files identifying the resource to manage.
--force                          # Force the operation.
--dry-run=''                     # Must be "none", "server", or "client". Use to preview the operation without making changes.
-o, --output=''                  # Output format. Options: 'yaml' or 'json'.
-w, --watch=false                # Watch for changes after the operation.
-n, --namespace=[]               # Namespace to use for the operation.
-l, --labels=''                  # Comma-separated labels to apply to the resource. Will override previous values.
#                      Create
--edit=false                     # Edit the API resource before creating it.

--save-config                    # Save the configuration of the current object in its annotation. Useful for future kubectl apply operations.
#                      Run
--annotations=[]                 # Annotations to apply to the pod.

--attach=false                   # Wait for the Pod to start running, then attach to it. Default is false unless '-i/--stdin' is set.

--command=false                  # Use extra arguments as the 'command' field in the container, rather than the 'args' field.

--env=[]                         # Environment variables to set in the container.

--expose=false                   # Create a ClusterIP service associated with the pod. Requires `--port`.

--image=''                       # The image for the container to run.

--port=''                        # The port that this container exposes.

--privileged=false               # Run the container in privileged mode.

-q, --quiet=false                # Suppress prompt messages.

--restart='Always'               # The restart policy for this Pod. Legal values: [Always, OnFailure, Never].

--rm=false                       # Delete the pod after it exits. Only valid when attaching to the container.

-i, --stdin=false                # Keep stdin open on the container in the pod, even if nothing is attached.

-t, --tty=false                  # Allocate a TTY for the container in the pod.
#                       Expose    
--cluster-ip=''                  # ClusterIP to be assigned to the service. Leave empty to auto-allocate, or set to 'None' to create a headless service.

--external-ip=''                 # Additional external IP address (not managed by Kubernetes) to accept for the service.

--load-balancer-ip=''            # IP to assign to the LoadBalancer. If empty, an ephemeral IP will be created and used (cloud-provider specific).

--name=''                        # The name for the newly created object.

--protocol=''                    # The network protocol for the service to be created. Default is 'TCP'.

--selector=''                    # A label selector to use for this service. Only equality-based selector requirements are supported.

--target-port=''                 # Name or number for the port on the container that the service should direct traffic to. Optional.

--type=''                        # Type for this service: ClusterIP, NodePort, LoadBalancer, or ExternalName. Default is 'ClusterIP'.

-A, --all-namespaces=false       # List the requested object(s) across all namespaces.

-n, --namespace=[]               # Namespace to use for the operation.

-f, --filename=[]                # Filename, directory, or URL to files identifying the resource to get from a server.

--no-headers=false               # When using the default or custom-column output format, don't print headers.

-o, --output=''                  # Output format. Options: 'wide'.

-l, --selector=''                # Selector (label query) to filter on, supports '=', '==', and '!='.

--show-kind=false                # List the resource type for the requested object(s).

--show-labels=false              # Show all labels as the last column when printing.
#                       Get
-w, --watch=false                # Watch for changes after listing/getting the requested object.

--watch-only=false               # Watch for changes to the requested object(s), without listing/getting first.

--all=false                      # Delete all resources, in the namespace of the specified resource types.

--force=false                    # Immediately remove resources from API and bypass graceful deletion.

--grace-period=-1                # Period of time in seconds given to the resource to terminate gracefully. Ignored if negative.

--ignore-not-found=false         # Treat "resource not found" as a successful delete. Defaults to "true" when --all is specified.

-i, --interactive=false          # Delete resource only when the user confirms.

--now=false                      # Signal resources for immediate shutdown.

--timeout=0s                     # The length of time to wait before giving up on a delete.

--wait=true                      # Wait for resources to be gone before returning. This waits for finalizers.
#                       Edit
--save-config=false              # Save the configuration of the current object in its annotation.
#                       Exec
-c, --container=''               # Container name. If omitted, use the default container or the first container in the pod.

-q, --quiet=false                # Only print output from the remote session.

-i, --stdin=false                # Pass stdin to the container.

-t, --tty=false                  # Stdin is a TTY.
#                       logs
--all-containers=false           # Get all containers' logs in the pod(s).

-c, --container=''               # Print the logs of this container.

-f, --follow=false               # Specify if the logs should be streamed.

--max-log-requests=5             # Specify maximum number of concurrent logs to follow when using by a selector. Defaults to 5.

--pod-running-timeout=20s        # The length of time to wait until at least one pod is running.

--prefix=false                   # Prefix each log line with the log source (pod name and container name).

-p, --previous=false             # Print the logs for the previous instance of the container in a pod if it exists.

--timestamps=false               # Include timestamps on each line in the log output.

--record=true                    # Record the current kubectl command in the resource annotation.

--selector app=frontend,env=dev --no-headers | wc -l  # Example of using a selector to filter resources and count them.

kubectl apply/create -f /filepath
kubectl replace -f /filepath --force        
kubectl get po --watch      
kubectl get po -o wide (internal IP & Node) kubectl get po -A       
kubectl delete po --all
kubectl get/describe/edit/delete <object> <object name> | grep -i label -7      | grep -i -A 1 -B 1 args         after -B before
kubectl logs -f <pod name> -c <container name>
kubectl get/describe/edit/delete all,clusters,nodes,po,rc,rs,deploy,quota,cm,secret,svc,job,cronjob,sa,token,role,rolebinding
kubectl exec <pod name> -c <cont name> -- whoami    
kubectl exec -it <my-pod> -- sh 
docker exec -it <node name> /bin/sh
kubectl edit deploy/svc/job <name> --record

kubectl run <pod name> --image <image name> # only if resource quota isn’t set

kubectl run my-pod --image=nginx --restart=Never --port=80 --labels="app=my-pod,env=production" --env="ENVIRONMENT=production" --namespace default --dry-run=client -o yaml > filename

kubectl replace -f <path-to-file.yaml> --force          

kubectl run <> --image kodekloud/webapp-color --dry-run=client -o yaml -- --color red # command: python run main.py
kubectl run <> --image kodekloud/webapp-color --dry-run=client -o yaml --command -- color red
kubectl run <> --image=busybox --dry-run=client -o yaml --command -- sleep 3600

kubectl create quota <> --hard=cpu=4,memory=8Gi,pods=10,services=5,persistentvolumeclaims=2 --namespace=<> --dry-run=client
kubectl set resources pod <> --limits="cpu=500m,memory=128Mi" --requests="cpu=250m,memory=64Mi" --dry-run=client

kubectl create cm abc --from-literal key=value --from-literal APP_COLOR=green --dry-run=client -o yaml  # From key-value pairs
kubectl create cm abc --from-file /home/ibtisam/k8s/10-1/cm.yaml --dry-run=client -o yaml           # From a file
kubectl create secret generic <> --from-literal DB_Host=sq101 --from-literal DB_User=root --from-literal DB_Password=password123
echo -n 'value' | base64                    
echo -n 'sq101' | base64                    # Base64 encoded
echo 'base64_encoded_value' | base64 --decode       
echo 'c3ExMDE=' | base64 --decode

kubectl taint node <ibtisam-worker> flower=rose:NoSchedule      # associated with pod tolerations
kubectl taint node <ibtisam-worker> flower=rose:NoSchedule- key=value:tainteffect                   # remove the taint
kubectl describe node <ibtisam-control-plane> | grep -i taint -5
kubectl label node <ibtisam-worker2> cpu=large      # key=value associated with nodeSelector & nodeAffinity     cpu-

kubectl logs -f <pod name> -c <container name>      
kubectl logs <pod> <con>

kubectl create service <type, small let> <name> --tcp=<port>:<targetPort> # <type>: ClusterIP, NodePort, LoadBalancer (avoid this command)
kubectl expose <resource> <name> --name <> --port=<> --target-port=<> --type=<service-type> # <resource>: <deployment/replicaset/pod>
kubectl expose po <pod name> --name <svc name> --port=<> --target-port=<> --type <> --dry-run=client # (no pod labels, no expose)

minikube ssh    
ssh username@ip     
docker exec -it <node name> </bin/bash> or <bash> or </bin/sh> or <sh>  jump into node
curl <pod_IP:service_port / service IP:servive_port>                # inside the node, whether ClusterIP or NodePort
kubectl port-forward svc/c-ip-svc host:svc_port > /dev/null 2>&1 &  # from outside, whether ClusterIP or NodePort, Port-forwarding, if different network
curl <node_ip:NordPort> # from outside, NodePort, if Node_IP & localhost_IP (ip r l) share the same network.
host=svc    <service name>.<namespace>.svc.cluster.local (if diff namespace), connecting one pod to another within same/diff ns

# wlp6s0: 192.168.100.10        minikube: 192.168.59.100        ibtisam-worker: 172.18.0.3  docker0: 172.17.0.1 lo: 127.0.0.1 pod: 10.244.1.2           My IP Address is: IPv4: 439.195.86.299

kubectl create deployment my-deployment --image=nginx:1.19.2 --replicas=3 --port=80 --labels="app=my-deployment,env=production" --env="ENVIRONMENT=production" --dry-run=client -o yaml | kubectl apply --record=true -f-  # <or --record>

kubectl create deploy <name> --image <name> -r 3 --port 3741 --record --dry-run=client -o yaml > filename

# REVISION: Each time you update the Deployment (e.g., by changing the image, replicas, or configuration), K8s creates a new revision.

kubectl edit deploy dp7xyz      # (change the image)    
kubectl scale deploy dp7xyz --replicas 6                # scale up/down
kubectl edit deploy dp7xyz --record # (change the image)    
kubectl set image deploy <> <ContainerName>=nginx:1.22-alpine --record
kubectl rollout status deploy dp7xyz                # real-time status; Successful rollout, Rolling updates, Error messages
kubectl rollout history deploy dp7xyz --revision <n>        # track the history of changes to your Deployment
kubectl rollout undo deploy dp7xyz --to-revision <n>

kubectl get ns      # default   kube-node-lease     kube-public         kube-system         local-path-storage
kubectl create ns <ibtisam> --dry-run=client -o yaml
kubectl apply/delete <object> <object name> -n <namespace>      
kubectl get all -n <>           #   specify -n <>
kubectl config get-contexts     
kubectl config view --minify --output yaml | grep namespace:        # current/verify
kubectl config set-context --current --namespace <>                 # to modify

kubectl create job <> --image=busybox --dry-run=client -o yaml -- sh -c "echo Hello from Kubernetes Job! && sleep 30"

kubectl create cronjob <> --schedule="*/5 * * * *" --image=<> --dry-run=client -o yaml -- sh -c "echo Hello CronJob! && sleep 30"

kubectl logs <pod name> -c <container name>                         # logs, not log. No object, only object name

kubectl create sa dashboard-sa --dry-run=client -o yaml
kubectl create token <sa name>
kubectl create role <pod-reader> --verb=get,list,watch --resource=pods --namespace=default      # resource:pods/deployments
kubectl create rolebinding <pod-reader-binding> --role=pod-reader --serviceaccount=default:dashboard-sa --namespace=default

kubectl create ingress <> --rule="myapp.example.com/*=myapp-service:80" --rule=<> --dry-run=client -o yaml      # pathType: Prefix
kubectl create ingress <> --rule="myapp.example.com/=myapp-service:80" --rule=<> --dry-run=client -o yaml       # pathType: Exact

kubectl top pod/node
kind get clusters                       OR  kubectl config get-clusters
kubectl config get-contexts
kubectl config view
docker ps; docker ps -a
kind delete cluster --name <your-cluster-name>          kubectl config delete-cluster kind-ibtisam      both aren't the same.
kind create cluster --name <your-cluster-name>
docker inspect/logs <ibtisam-control-plane>
docker logs ibtisam-external-load-balancer
kind get clusters; kubectl config get-clusters; kubectl config get-contexts; kubectl config view; docker ps