Kubernetes in One Shot

This README is a comprehensive guide for "Kubernetes in One Shot." It contains categorized commands from your history, structured by core Kubernetes topics. Each command is briefly described for ease of understanding and use.

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Core Concepts

Monolithic vs Microservices, Kubernetes Architecture

1. kubectl cluster-info
   Display cluster information to understand the Kubernetes architecture.

Setup On Local/AWS EC2

1. kind create cluster --name=tws-cluster --config=config.yml
   Create a Kubernetes cluster using Kind with a specific configuration.
2. kubectl config use-context kind-tws-cluster
   Switch the context to the Kind cluster.

Kubectl and Pods

1. kubectl get nodes
   List all nodes in the Kubernetes cluster.
2. kubectl run nginx --image=nginx -n nginx
   Create a pod named nginx in the nginx namespace.
3. kubectl describe pod nginx -n nginx
   Display detailed information about the nginx pod.

Namespaces, Labels, Selectors, Annotations

1. kubectl create namespace monitoring
   Create a namespace for monitoring resources.
2. kubectl get namespace
   List all namespaces in the cluster.
3. kubectl label namespace monitoring team=devops
   Add a label to the monitoring namespace.
4. kubectl describe namespace monitoring
   Display detailed information about the monitoring namespace.

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Workloads

Deployments

1. kubectl apply -f deployment.yml
   Deploy a workload defined in deployment.yml.
2. kubectl scale deployment nginx-deployment --replicas=3 -n nginx
   Scale the deployment to 3 replicas.

StatefulSets

1. kubectl apply -f statefulset.yml
   Deploy a StatefulSet defined in statefulset.yml.
2. kubectl describe statefulset mysql -n database
   Display detailed information about a StatefulSet.

DaemonSets

1. kubectl apply -f daemonset.yml
   Deploy a DaemonSet for running pods on every node.
2. kubectl describe daemonset fluentd -n logging
   Display details about a DaemonSet.

ReplicaSets

1. kubectl apply -f replicaset.yml
   Deploy a ReplicaSet for managing pod replicas.
2. kubectl describe replicaset nginx-replicaset -n nginx
   Show detailed information about the ReplicaSet.

Jobs and CronJobs

1. kubectl apply -f job.yml
   Deploy a Job defined in job.yml.
2. kubectl apply -f cronjob.yml
   Deploy a CronJob to schedule recurring tasks.

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Networking

Cluster Networking

1. kubectl get svc -A
   List all services in the cluster.

Services

1. kubectl apply -f service.yml
   Expose an application as a service.
2. kubectl describe svc nginx-service -n nginx
   Show details of the nginx service.

Ingress

1. kubectl apply -f ingress.yml
   Configure an Ingress resource for routing traffic.
2. kubectl describe ingress nginx-ingress -n nginx
   Display details about an Ingress resource.

Network Policies

1. kubectl apply -f networkpolicy.yml
   Apply network restrictions between pods and services.

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Storage

Persistent Volumes (PV), Persistent Volume Claims (PVC)

1. kubectl apply -f persistentVolume.yml
   Create a PersistentVolume.
2. kubectl apply -f persistentVolumeClaim.yml
   Request storage through a PersistentVolumeClaim.

StorageClasses

1. kubectl get storageclass
   List all storage classes available in the cluster.

ConfigMaps and Secrets

1. kubectl create configmap app-config --from-file=config.properties
   Create a ConfigMap from a file.
2. kubectl create secret generic db-credentials --from-literal=username=admin --from-literal=password=admin123
   Create a Secret with database credentials.

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Scaling and Scheduling

HPA and VPA

1. kubectl autoscale deployment nginx --cpu-percent=50 --min=1 --max=10 -n nginx
   Enable Horizontal Pod Autoscaler (HPA).
2. kubectl apply -f vpa.yml
   Deploy a Vertical Pod Autoscaler (VPA).

Node Affinity and Taints/Tolerations

1. kubectl taint nodes node1 key=value:NoSchedule
   Apply a taint to a node.
2. kubectl apply -f node-affinity.yml
   Define node affinity rules for pods.

Resource Quotas, Limits, Probes

1. kubectl apply -f resourcequota.yml
   Set resource limits and quotas in a namespace.
2. kubectl describe quota my-quota -n dev
   Display details of a resource quota.

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Cluster Administration

RBAC

1. kubectl apply -f role.yml
   Define a Role for access control.
2. kubectl apply -f rolebinding.yml
   Bind the Role to a user or service account.

Custom Resource Definitions (CRDs)

1. kubectl apply -f crd.yml
   Define a Custom Resource Definition.
2. kubectl get crd
   List all Custom Resource Definitions.

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Monitoring and Logging

Metrics Server

1. kubectl apply -f metrics-server.yml
   Deploy the metrics server.
2. kubectl top node
   Display resource usage by nodes.

Prometheus and Grafana

1. helm install prometheus-stack prometheus-community/kube-prometheus-stack --namespace monitoring
   Install Prometheus and Grafana for monitoring.
2. kubectl port-forward svc/prometheus-stack-grafana 3000:80 -n monitoring --address=0.0.0.0
   Access Grafana through port forwarding.

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Advanced Features

Helm

1. helm create my-chart
   Create a Helm chart.
2. helm install my-app my-chart -n my-namespace --create-namespace
   Deploy an application using a Helm chart.

SideCar and Init Containers

1. kubectl apply -f init-container.yml
   Deploy a pod with an Init Container.
2. kubectl apply -f sidecar-container.yml
   Deploy a pod with a SideCar Container.

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Security

1. kubectl apply -f podsecuritypolicy.yml
   Define pod security standards.
2. kubectl apply -f secrets-encryption.yml
   Configure encryption for Kubernetes Secrets.

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Cloud-Native Kubernetes

Managed Services (EKS, AKS, GKE)

1. eksctl create cluster --name my-cluster
   Create an EKS cluster using eksctl.

Cluster Autoscaler

1. kubectl apply -f cluster-autoscaler.yml
   Deploy the Cluster Autoscaler.

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Debugging and Troubleshooting

1. kubectl logs pod-name -n namespace
   View logs for a specific pod.
2. kubectl describe pod pod-name -n namespace
   Display detailed information about a pod.
3. kubectl exec -it pod-name -n namespace -- bash
   Access a running container.

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Projects

Resources for Projects:

1. Kubestarter: GitHub Repository
   A comprehensive starter template for Kubernetes projects.

2. CI/CD Integration: Wanderlust Mega Project
   Learn Kubernetes CI/CD with Jenkins and ArgoCD.

3. Microservices: Full Stack ChatApp
   Build and deploy a full-stack chat application.

4. Monitoring: K8s Voting App
   Implement monitoring with Prometheus and Grafana for a voting app.