ITG: BLOG

kubectl delete pod <PODNAME> --grace-period=0 --force --namespace <NAMESPACE>

[user@host ~]# helm install --namespace=<<NAMESPACE>> gitlab-runner -f values.yaml gitlab/gitlab-runner
NAME: gitlab-runner
LAST DEPLOYED: Sun Mar 12 12:31:55 2023
NAMESPACE: kube-system
STATUS: deployed
REVISION: 1
TEST SUITE: None
NOTES:
Your GitLab Runner should now be registered against the GitLab instance reachable at: "https://<<URL>>/"
Runner namespace "<<NAMESPACE>>" was found in runners.config template.

kubectl create token <Service Account Name> to create the token.

https://kubernetes.io/docs/concepts/configuration/secret/#service-account-token-secrets

https://kubernetes.io/docs/reference/kubernetes-api/authentication-resources/token-request-v1/

https://www.programmingwithwolfgang.com/use-the-tokenrequest-api-to-create-tokens-in-kubernetes/

Create -> Post
Read -> Get
Update -> Put
Delete -> Delete

https://kubernetes.io/docs/reference/generated/kubernetes-api/v1.26/

https://kubernetes.io/docs/reference/access-authn-authz/authorization/

4 Authorization Modes:
Node, ABAC, RBAC & Webhook

https://kubernetes.github.io/ingress-nginx/examples/rewrite/

Deployment¶

Rewriting can be controlled using the following annotations:

Name	Description	Values
nginx.ingress.kubernetes.io/rewrite-target	Target URI where the traffic must be redirected	string

Helm helps you manage Kubernetes applications — Helm Charts help you define, install, and upgrade even the most complex Kubernetes application.

https://helm.sh/
https://github.com/helm/helm/releases

Install Helm

curl -fsSL -o get_helm.sh https://raw.githubusercontent.com/helm/helm/main/scripts/get-helm-3

chmod 700 get_helm.sh

./get_helm.sh

https://www.centlinux.com/2022/11/install-kubernetes-master-node-rocky-linux.html

CNI Plugin:
https://www.tkng.io/cni/flannel/

kubeadm init

kubeadm init --pod-network-cidr=10.244.0.0/16

Create file: /run/flannel/subnet.env

FLANNEL_NETWORK=10.244.0.0/16
FLANNEL_SUBNET=10.244.0.1/24
FLANNEL_MTU=1450
FLANNEL_IPMASQ=true

Testing Deployment

kubectl get pods --all-namespaces
kubectl run test --image=nginx
kubectl get pod -o wide

Flannel File Path:

/opt/cni/bin/flannel

Kubelet Logs:
journalctl -u kubelet

kubectl cluster-info

Useful Commands:

kubectl get pods –all-namespaces
kubectl run test –image=nginx
kubectl get pod -o wide

kubeadm

kubeadm reset
kubeadm init
kubeadm get node
kubeadm config images pull
kubeadm join –help | grep token

Kubernetes Deployment:

Create YAML File:
test-deployment.yaml

Apply/Create YAML file
kubectl apply -f test-deployment.yaml

Display Created Pods
kubectl get pod
kubectl get deployment
kubectl delete pod test 1 test 2

Display Service & Endpoints
kubectl get svc
kubectl describe svc service-name
kubectl get ep (endpoints)

POD DNS Resolution not working:
kubectl -n kube-system rollout restart deployment coredns

Fully Qualified Domain Name:
<servicename>.<namespace>.svc.cluster.local

https://www.centlinux.com/2022/11/install-kubernetes-master-node-rocky-linux.html