{"id":396,"date":"2023-11-05T09:38:38","date_gmt":"2023-11-05T09:38:38","guid":{"rendered":"https:\/\/devopsopen.com\/?p=396"},"modified":"2023-11-27T00:08:17","modified_gmt":"2023-11-27T00:08:17","slug":"boite-a-outil-k8s","status":"publish","type":"post","link":"https:\/\/devopsopen.com\/index.php\/2023\/11\/05\/boite-a-outil-k8s\/","title":{"rendered":"Bo\u00eete \u00e0 outil K8S"},"content":{"rendered":"

get all resources in a cluster<\/h2>\n
kubectl get all -A\n<\/code><\/pre>\n
Sort cpu or memory of pods or nodes(Find the pod who consumm more than others)<\/h2>\n
install server metrics<\/p>\n
wget  https:\/\/github.com\/kubernetes-sigs\/metrics-server\/releases\/latest\/download\/components.yaml\n<\/code><\/pre>\n
add those line into file yaml<\/p>\n
        command:\n          - \/metrics-server\n          - --kubelet-insecure-tls\n          - --kubelet-preferred-address-types=InternalIP<\/code><\/pre>\n
like <\/p>\n
spec:\n  selector:\n    matchLabels:\n      k8s-app: metrics-server\n  strategy:\n    rollingUpdate:\n      maxUnavailable: 0\n  template:\n    metadata:\n      labels:\n        k8s-app: metrics-server\n    spec:\n      containers:\n      - args:\n        - --cert-dir=\/tmp\n        - --secure-port=4443\n        - --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname\n        - --kubelet-use-node-status-port\n        - --metric-resolution=15s\n        image: registry.k8s.io\/metrics-server\/metrics-server:v0.6.4\n        command:\n          - \/metrics-server\n          - --kubelet-insecure-tls\n          - --kubelet-preferred-address-types=InternalIP\n        imagePullPolicy: IfNotPresent\n        livenessProbe:\n          failureThreshold: 3\n          httpGet:<\/code><\/pre>\n
then apply the file<\/p>\n
kubectl apply -f components.yaml<\/code><\/pre>\n
then get sorted informations<\/p>\n
kubectl top pod | awk '{ print $1 ";" $2 ";" $3}' > sort.in ; sort -t";" -V -k3 sort.in\n<\/code><\/pre>\n
-t is seprator
\n-V alphanumeric
\n-k3 column 3 to be sorted
\nsort.in the file input<\/p>\n
Info cluster service CIDR...<\/h2>\n
kubectl cluster-info dump | grep -i service-cluster\nkubectl cluster-info dump | grep -i cluster-cidr<\/code><\/pre>\n
Change image of a deployment<\/h2>\n
create a deployment with image<\/p>\n
kubectl create deploy nginx-deploy --image=nginx:1.16 --replicas=1<\/code><\/pre>\n
change the image of the deployment<\/p>\n
kubectl set image deployment nginx-deploy nginx=nginx:1.17<\/code><\/pre>\n
get all pod in a specific node<\/h2>\n
kubectl get pods --all-namespaces -o wide --field-selector spec.nodeName=<node><\/code><\/pre>\n
Migrate pods where are in a specific node to another node<\/h2>\n
unschedule pods with cordon command to not let other pods to come to this node.
\nkubectl cordon node-1<\/p>\n
drain node(vider) to exclude pods to other pods that are scheduled. drain containt the cordon command naturally
\nkubectl drain node-2 --force<\/p>\n
get node scheduled with command uncordon
\nkubectl uncordon node-1<\/p>\n
Make a node unavailable<\/h2>\n
kubectl drain node-01 --force  \nor\nkubectl drain node-01 --grace-period 0<\/code><\/pre>\n
Creation  pod:<\/h2>\n
kubectl run static-busybox --image=busybox --command "sleep 1000" --dry-run=client -o yaml<\/code><\/pre>\n
Cr\u00e9ation deploy<\/h2>\n
kubectl create deployment hr-web-app --image=redis --replicas=3 --dry-run=client -o yaml<\/code><\/pre>\n
Scale a Deploy or RS<\/h2>\n
kubectl scale deploy\/test2 --replicas=3<\/code><\/pre>\n
Expose a pod (deploy or rs)<\/h2>\n
kubectl expose pod messaging --name=messaging-service --type=ClusterIP --port=6379<\/code><\/pre>\n
Create a static pod (important because static pod does not scheduled by api, you should put it in manifests)<\/h2>\n
kubectl run --restart=Never --image=busybox static-busybox --dry-run=client -o yaml --command -- sleep 1000 > \/etc\/kubernetes\/manifests\/static-busybox.yaml<\/code><\/pre>\n
Create deploy with replicas<\/h2>\n
kubectl create deployment hr-web-app --image=kodekloud\/webapp-color --replicas=2<\/code><\/pre>\n
Correct a pod description with edit command. when you edit a pod, a temp file is created and you should force<\/h2>\n
kubectl edit pod namepod\nkubectl replace -f \/tmp\/kubectl-edit-xxxx.yaml --force<\/code><\/pre>\n
Expose a deploy with a specific NodePort. after this command you should change the port wanted in the file<\/h2>\n
kubectl expose deployment hr-web-app --type=NodePort --port=8080 --name=hr-web-app-service --dry-run=client -o yaml > hr-web-app-service.yaml<\/code><\/pre>\n
Get OSImage of nodes and put in the file<\/h2>\n
kubectl get nodes -o jsonpath='{.items[*].status.nodeInfo.osImage}' > \/opt\/outputs\/nodes_os_x43kj56.txt<\/code><\/pre>\n
Create a persistent volume<\/h2>\n
apiVersion: v1\nkind: PersistentVolume\nmetadata:\n  name: pv-analytics\nspec:\n  capacity:\n    storage: 100Mi\n  volumeMode: Filesystem\n  accessModes:\n    - ReadWriteMany\n  hostPath:\n      path: \/pv\/data-analytics<\/code><\/pre>\n
Lens pour g\u00e9rer son Cluster<\/h2>\n