K8S the hard way based on kelsey hightower repo
go 1.13 or later
cd a.gcloud
All resources are deployed in google cloud. You can create a free account and get a 300$ for free. These money should be enough to get accommodated with main k8s components. Deploy script will spin up 6 VMs, 3 masters and 3 worker nodes. You have to install gcloud prior to run deploy script
cd b.local_vagrant
Deploy script will spin up 3 VMs, 1 master and 2 worker nodes. You have to install vagrant and virtualBox (and also git-bash in case of windows OS) prior to run deploy script
./deploy_all.sh
add below line in /etc/hosts
10.240.0.10 k8s.local grafana.k8s.local prometheus.k8s.local alaertmanager.k8s.localGrafana should be available at https://grafana.k8s.local:30443
Prometheus should be available at https://prometheus.k8s.local:30443
Alertmanager should be available at https://alertmanager.k8s.local:30443
K8S dashboard should be available at https://k8s.local:30443/dashboard/
An alternative for accessing k8s dashboard will by using k8s proxy
In order to access k8s dashboard run
kubectl proxy
Open your browser and access
http://localhost:8001/api/v1/namespaces/kubernetes-dashboard/services/https:kubernetes-dashboard:/proxy/
Select token authentication and enter the below output command token:
kubectl -n kube-system describe secret \
$(kubectl -n kube-system get secret | grep admin | awk '{print $1}') | \
egrep "token:" | cut -d ':' -f2 |tr -d ' '
./cleaning_up.sh
kubectl api-versions
kubectl api-resources
kubectl get componentstatuses
kubectl get --raw /healthz
kubectl describe apiservice v1beta1.metrics.k8s.io
kubectl get --raw "/apis/metrics.k8s.io" | jq .
kubectl get apiservice
kubectl explain deployment --recursive
kubectl logs dashboard-metrics-scraper-xxx -f
kubectl edit deployment metrics-server
kubectl create serviceaccount dashboard-admin
kubectl create clusterrolebinding dashboard-admin --clusterrole=cluster-admin --serviceaccount=kubernetes-dashboard:dashboard-admin
kubectl get roles.rbac.authorization.k8s.io
kubectl get sa
kubectl get secret --all-namespaces
kubectl describe secret kubernetes-dashboard-token-gjpqk
kubectl config view
alias k='kubectl'
alias kns='kubectl config set-context --current --namespace'
kns kube-system
k get po,svc --all-namespaces
k get ev (get events)
k get cs (componentstatuses)
k get limits --all-namespaces (LimitRange)
k get pdb --all-namespaces (PodDisruptionBudget)
k get quota --all-namespaces (ResourceQuota)
k get hpa --all-namespaces (HorizontalPodAutoscaler)
k get netpol --all-namespaces (NetworkPolicy)
k create ns test
kns test
k create serviceaccount test
k create role test-role --verb=get --verb=list --resource=services
k create rolebinding test-rb --role=test-role --serviceaccount=test:test
k run test --image=ubuntu --serviceaccount=test -it -- bash
curl -k https://172.16.11.1/api/v1/namespaces/test/services -H 'Accept: application/json' -H "Authorization: Bearer $(cat /run/secrets/kubernetes.io/serviceaccount/token)" --works
curl -k https://172.16.11.1/api/v1/namespaces/test/pods -H 'Accept: application/json' -H "Authorization: Bearer $(cat /run/secrets/kubernetes.io/serviceaccount/tokn)" --forbidden
k delete deploy test
- List all Persistent Volumes sorted by their name
kubectl get pv | grep -v NAME | sort -k 2 -rh
- Find which pod is taking max CPU
kubectl top pod
- Getting a Detailed Snapshot of the Cluster State
kubectl cluster-info dump --all-namespaces > cluster-state
- Save the manifest of a running pod
kubectl get pod name -o yaml --export > pod.yml
- Save the manifest of a running deployment
kubectl get deploy name -o yaml --export > deploy.yml
- Use dry-run to create a manifest for a deployment
kubectl run ghost --image=ghost --restart=Always --expose --port=80 --output=yaml --dry-run > ghost.yaml
k apply -f ghost.yaml
k get all
Delete evicted pods
kubectl get po -A -o json | \
jq '.items[] | select(.status.reason!=null) | select(.status.reason | contains("Evicted")) | \
"kubectl delete po \(.metadata.name) -n \(.metadata.namespace)"' | xargs -n 1 bash -c
- Find all deployments which have no resource limits set
kubectl get deploy -o json | \
jq ".items[] | select(.spec.template.spec.containers[].resources.limits==null) | {DeploymentName:.metadata.name}"
- Create a yaml for a job
kubectl run --generator=job/v1 test --image=nginx --dry-run -o yaml
- Find all pods in the cluster which are not running
kubectl get pod --all-namespaces -o json | jq '.items[] | select(.status.phase!="Running") | [ .metadata.namespace,.metadata.name,.status.phase ] | join(":")'
- List all pods order by MEM usage
kubectl top pods --no-headers -A | sort --reverse --numeric -k 4
- List the top 3 nodes with the highest CPU usage
kubectl top nodes | sort --reverse --numeric -k 3 | head -n3
- List the top 3 nodes with the highest MEM usage
kubectl top nodes | sort --reverse --numeric -k 5 | head -n3
- Get rolling Update details for deployments
kubectl get deploy -o json |
jq ".items[] | {name:.metadata.name} + .spec.strategy.rollingUpdate"
- List pods and its corresponding containers
kubectl get pods -o='custom-columns=PODS:.metadata.name,CONTAINERS:.spec.containers[*].name'
- Get quota for each node:
kubectl get nodes --no-headers | awk '{print $1}' | xargs -I {} sh -c 'echo {}; kubectl describe node {} | grep Allocated -A 5 | grep -ve Event -ve Allocated -ve percent -ve -- ; echo'
- Get nodes which have no taints
kubectl get nodes -o json | jq -r '.items[] | select(.spec.taints == null) | "\(.metadata.name)"'
https://kubernetes.io/docs/reference/kubectl/cheatsheet/
https://matthewdavis.io/kubectl-most-useful-commands-a-growing-list/
https://github.com/dennyzhang/cheatsheet-kubernetes-A4
http://kubernetesbyexample.com/
http://crunchtools.com/competition-heats-up-between-cri-o-and-containerd-actually-thats-not-a-thing/