Managing Amazon EBS Volumes and Snapshots Across Regions

 

🚀 Kubernetes Setup (Local)

🟢 Minikube

Start cluster

minikube start

Check

kubectl get nodes
kubectl cluster-info

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📦 POD

✅ What is Pod?

Smallest deployable unit in Kubernetes
Contains:

• 1 or more containers

• same network

• same storage

✅ Why Pod?

Because containers cannot run directly, they must run inside Pods.

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🔹 Pod Commands

kubectl get pods
kubectl describe pod mypod
kubectl logs mypod
kubectl delete pod mypod
kubectl exec -it mypod -- bash

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🔹 Create Pod (quick)

kubectl run nginx --image=nginx --restart=Never

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🔹 Pod YAML

apiVersion: v1
kind: Pod
metadata:
  name: nginx-pod
spec:
  containers:
  - name: nginx
    image: nginx
    ports:
    - containerPort: 80

---

🔹 Generate YAML automatically

kubectl run nginx --image=nginx --dry-run=client -o yaml > pod.yaml

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🔁 REPLICASET

✅ What is ReplicaSet?

Ensures fixed number of pods always running

✅ Why?

If pod dies → auto recreate

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🔹 Commands

kubectl get rs
kubectl scale rs myrs --replicas=5
kubectl delete rs myrs

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🔹 ReplicaSet YAML

apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: nginx-rs
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx

---

🔹 Generate YAML

kubectl create rs nginx --image=nginx --dry-run=client -o yaml

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🚀 DEPLOYMENT

✅ What is Deployment?

Manages ReplicaSets + updates

✅ Why?

✔ Rolling updates
✔ Rollback
✔ Zero downtime

---

🔹 Commands

kubectl get deploy
kubectl scale deploy nginx --replicas=5
kubectl rollout status deploy nginx
kubectl rollout undo deploy nginx
kubectl set image deploy/nginx nginx=nginx:1.25

---

🔹 Deployment YAML

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx-deploy
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx

---

🔹 Generate YAML

kubectl create deployment nginx --image=nginx --dry-run=client -o yaml > deploy.yaml

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📊 METRICS SERVER

✅ What is Metrics Server?

Collects:

• CPU

• Memory

for:

• HPA

• kubectl top

---

🔹 Install (Minikube)

minikube addons enable metrics-server

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🔹 Test

kubectl top nodes
kubectl top pods

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⚡ HPA (Horizontal Pod Autoscaler)

What?

Auto scale pods based on CPU/memory

Flow

Deployment → Metrics Server → HPA → Auto scale

Yes bro 👇
👉 First create Deployment
👉 Then attach HPA

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🔹 Command

kubectl autoscale deployment nginx --cpu-percent=50 --min=2 --max=10

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🔹 Check

kubectl get hpa
watch kubectl get pods

---

🔹 YAML

apiVersion: autoscaling/v2
kind: HorizontalPodAutoscaler
metadata:
  name: nginx-hpa
spec:
  scaleTargetRef:
    apiVersion: apps/v1
    kind: Deployment
    name: nginx-deploy
  minReplicas: 2
  maxReplicas: 10
  metrics:
  - type: Resource
    resource:
      name: cpu
      target:
        type: Utilization
        averageUtilization: 50

---

🖥️ DAEMONSET

🔷 What is DaemonSet?

Runs 1 pod on every node

🔷 Why?

Used for:

• logging

• monitoring

• agents

Examples:

• fluentd

• node exporter

---

🔹 Commands

kubectl get ds
kubectl delete ds myds

---

🔹 YAML

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: nginx-ds
spec:
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx

---

🔹 Generate YAML

kubectl create daemonset nginx --image=nginx --dry-run=client -o yaml

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🎨 kubecolor

🟢 kubecolor

Install

sudo apt install kubecolor

or

brew install kubecolor

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Use

kubecolor get pods
kubecolor get all

Alias

alias kubectl=kubecolor

Now all outputs colorful 😍

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🧠 Quick Memory Trick

Remember this order:

Pod → ReplicaSet → Deployment → HPA → DaemonSet

👉 Pod = run
👉 RS = maintain count
👉 Deployment = updates
👉 HPA = scale
👉 DS = run everywhere