til/docs/server/kubernetes.md

• https://kubernetes.io/

• https://kubernetes.io/docs/home/

  ### notes ###
  

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cheat sheet source - https://github.com/dennyzhang/cheatsheet-kubernetes-A4

Common Commands

Events & Metrics

Name	Command
View all events	kubectl get events --all-namespaces
List Events sorted by timestamp	kubectl get events –sort-by=.metadata.creationTimestamp

Node Maintenance

Name	Command
Mark node as unschedulable	kubectl cordon $NDOE_NAME
Mark node as schedulable	kubectl uncordon $NDOE_NAME
Drain node in preparation for maintenance	kubectl drain $NODE_NAME

Namespace & Security

Name	Command
List authenticated contexts	kubectl config get-contexts, ~/.kube/config
Set namespace preference	kubectl config set-context <context_name> --namespace=<ns_name>
Load context from config file	kubectl get cs --kubeconfig kube_config.yml
Switch context	kubectl config use-context <cluster-name>
Delete the specified context	kubectl config delete-context <cluster-name>
List all namespaces defined	kubectl get namespaces
List certificates	kubectl get csr
Check user privilege	kubectl –as=system:serviceaccount:ns-denny:test-privileged-sa -n ns-denny auth can-i use pods/list
Check user privilege	kubectl auth can-i use pods/list
Reference	Link: kubernetes yaml templates

Network

Name	Command
Temporarily add a port-forwarding	kubectl port-forward redis-134 6379:6379
Add port-forwaring for deployment	kubectl port-forward deployment/redis-master 6379:6379
Add port-forwaring for replicaset	kubectl port-forward rs/redis-master 6379:6379
Add port-forwaring for service	kubectl port-forward svc/redis-master 6379:6379
Get network policy	kubectl get NetworkPolicy

Patch

Name	Summary
Patch service to loadbalancer	kubectl patch svc $svc_name -p '{"spec": {"type": "LoadBalancer"}}'

Extenstions

Name	Summary
Enumerates the resource types available	kubectl api-resources
List api group	kubectl api-versions
List all CRD	kubectl get crd
List storageclass	kubectl get storageclass

Components & Services

Services on Master Nodes

Name	Summary
kube-apiserver	exposes the Kubernetes API from master nodes
etcd	reliable data store for all k8s cluster data
kube-scheduler	schedule pods to run on selected nodes
kube-controller-manager	node controller, replication controller, endpoints controller, and service account & token controllers

Services on Worker Nodes

Name	Summary
kubelet	makes sure that containers are running in a pod
kube-proxy	perform connection forwarding
Container Runtime	Kubernetes supported runtimes: Docker, rkt, runc and any OCI runtime-spec implementation.

Addons: pods and services that implement cluster features

Name	Summary
DNS	serves DNS records for Kubernetes services
Web UI	a general purpose, web-based UI for Kubernetes clusters
Container Resource Monitoring	collect, store and serve container metrics
Cluster-level Logging	save container logs to a central log store with search/browsing interface

Tools

Name	Summary
kubectl	the command line util to talk to k8s cluster
kubeadm	the command to bootstrap the cluster
kubefed	the command line to control a Kubernetes Cluster Federation
Kubernetes Components	Link: Kubernetes Components