👉🏻 롤링 업데이트 / Rolling Update
✔️ 애플리케이션을 무중단으로 점진적으로 새로운 버전으로 교체하는 과정을 의미합니다.
It refers to the process of gradually replacing an application with a new version without interruption.
👉🏻 스케일링 / Scaling
✔️ 시스템이나 애플리케이션에서 자원의 양을 늘리거나 줄여서 처리 능력이나 성능을 조절하는 것을 의미합니다.
It refers to adjusting processing power or performance in a system or application by increasing or decreasing the amount of resources.
👉🏻 ClusterIP와 NodePort의 차이
Difference between ClusterIP and NodePort
✔️ ClusterIP
— 기본 서비스 타입입니다. / This is the basic service type.
— 외부에서 직접 접근할 수 없고, 클러스터 내부 통신용으로 주로 사용됩니다.
It cannot be accessed directly from the outside and is primarily used for internal cluster communication.
✔️ NodePort
— 클러스터 내부뿐 아니라, 각 워커 노드에서 지정된 포트(30000 ~ 32767 범위)를 통해 외부에서 노드 IP와 이 포트를 통해 접근이 가능합니다.
In addition to within the cluster, external access is possible through the node IP and the designated port (range 30000 to 32767) on each worker node.
— ClusterIP는 클러스터 내부 전용 네트워크로 서비스에 접근할 때, NodePort는 외부에서도(노드 IP + 지정 포트로) 접근을 가능하게 해주는 서비스 타입입니다.
ClusterIP is a service type that allows access to the service via a private network within the cluster, while NodePort enables access from the outside (via Node IP + specified port).
👉🏻 애플리케이션 확장(스케일링) 및 롤링 업데이트
Application scaling and rolling updates
✔️ nginx-deployment.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
name: nginx-deployment
spec:
replicas: 1
selector:
matchLabels:
app: nginx
template:
metadata:
labels:
app: nginx
spec:
containers:
- name: nginx
image: nginx:latest
ports:
- containerPort: 80— yaml파일 적용 / Apply YAML file
kubectl apply -f nginx-deployment.yaml✔️ 애플리케이션 확장 (Replica 수 조절)
Application expansion (controlling the number of replicas)
— 현재 pod 수가 1개를(replicas: 1) 3개로 확장합니다.
Expands the current pod count from 1 (replicas: 1) to 3.
kubectl scale deployment nginx-deployment --replicas=3✔️ 롤링 업데이트 / rolling updates
— nginx1.23버전으로 교체 / Replaced with nginx version 1.23
— deployment(nginx-deployment)에서 nginx라는 이름의 컨테이너 이미지를 nginx:1.23으로 교체합니다.
Replace the container image named nginx in deployment(nginx-deployment) with nginx:1.23.
kubectl set image deployment/nginx-deployment nginx=nginx:1.23— 업데이트 진행상태 보기 / View update progress
kubectl rollout status deployment/nginx-deployment— 현재 배포(Deployment)의 상태를 이전 성공적이었던 버전으로 되돌리는 롤백 명령입니다.
This is a rollback command that reverts the current deployment state to a previously successful version.
kubectl rollout undo deployment/nginx-deployment✔️ 실제 작업 / actual work
–컨트롤 플레인에서 도커이미지 다운로드(nginx:1.23이 없는 경우)
Download Docker image from the control plane (if nginx:1.23 is not available)
docker pull nginx:1.23–다운로드된 이미지 확인 / Check downloaded images
(nginx:1.23 f5747a42e3ad 205MB 55.6MB )
MacBookAir nginx-test1 % docker images
i Info → U In Use
IMAGE ID DISK USAGE CONTENT SIZE EXTRA
docker/desktop-cloud-provider-kind:v0.5.0 4ad59ce20658 574MB 150MB U
docker/desktop-containerd-registry-mirror:v0.0.3 179a9ea3ae47 48.8MB 15.5MB U
docker/desktop-kubernetes:kubernetes-v1.34.1-cni-v1.7.1-critools-v1.33.0-cri-dockerd-v0.3.20-1-debian 12d6673564e0 552MB 169MB
docker/desktop-storage-provisioner:v3.0 57d2b6ad1c6f 75.4MB 21.9MB
docker/desktop-vpnkit-controller:v4.0 bdaff3408b1c 50MB 10.7MB
envoyproxy/envoy:v1.36.4 08acc53db6f4 233MB 58.8MB
kindest/node:v1.31.1 cd224d8da58d 1.47GB 413MB
kindest/node:v1.35.1 05d7bcdefbda 1.26GB 346MB U
nginx:1.23 f5747a42e3ad 205MB 55.6MB
nginx:latest 6e23479198b9 258MB 64.2MB
registry.k8s.io/coredns/coredns:v1.11.3 9caabbf6238b 81.8MB 16.9MB
registry.k8s.io/coredns/coredns:v1.12.1 e8c262566636 95.8MB 20.4MB
registry.k8s.io/etcd:3.5.16-0 c6a9d11cc5c0 213MB 67.9MB
registry.k8s.io/etcd:3.6.4-0 e36c08168342 306MB 98.2MB
registry.k8s.io/kube-apiserver:v1.32.2 c47449f3e751 123MB 26.2MB
registry.k8s.io/kube-apiserver:v1.34.1 b9d7c117f8ac 112MB 24.5MB
registry.k8s.io/kube-controller-manager:v1.32.2 399aa50f4d13 114MB 24MB
registry.k8s.io/kube-controller-manager:v1.34.1 2bf47c1b01f5 95.5MB 20.6MB
registry.k8s.io/kube-proxy:v1.32.2 83c025f0faa6 128MB 27.4MB
registry.k8s.io/kube-proxy:v1.34.1 913cc83ca0b5 101MB 22.8MB
registry.k8s.io/kube-scheduler:v1.32.2 45710d74cfd5 90.1MB 18.9MB
registry.k8s.io/kube-scheduler:v1.34.1 6e9fbc4e25a5 69.6MB 15.7MB
registry.k8s.io/pause:3.10 ee6521f290b2 786kB 266kB
— 롤링 업데이트 실행 / Run rolling update
kubectl set image deployment/nginx-deployment nginx=nginx:1.23— 모든pod에 nginx:1.23에 적용됐는지 확인하기(이미지 적용)
Check if nginx:1.23 has been applied to all pods (apply image)
MacBookAir nginx-test1 % kubectl set image deployment/nginx-deployment nginx=nginx:1.23
deployment.apps/nginx-deployment image updated
MacBookAir nginx-test1 % kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx-deployment-7878ff98b4-597k4 1/1 Running 0 3s
nginx-deployment-7878ff98b4-mqm62 1/1 Running 0 7s
nginx-deployment-7878ff98b4-nwn9r 1/1 Running 0 5s
MacBookAir nginx-test1 % kubectl describe pod nginx-deployment-7878ff98b4-597k4
... 중간 생략 / skipping the middle ...
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal Scheduled 41s default-scheduler Successfully assigned default/nginx-deployment-7878ff98b4-597k4 to desktop-worker
Normal Pulling 41s kubelet Pulling image "nginx:1.23"
Normal Pulled 41s kubelet Successfully pulled image "nginx:1.23" in 8ms (8ms including waiting). Image size: 55571911 bytes.
Normal Created 41s kubelet Container created
Normal Started 41s kubelet Container started
👉🏻 워커노드 접속 확인 하기 / Check worker node connection
✔️ NodePort로 deployment 노출하기 / Exposing a deployment via NodePort
MacBookAir nginx-test1 % kubectl expose deployment nginx-deployment --type=NodePort --port=80✔️ nodeIP 확인하기 / Check nodeIP
MacBookAir ~ % kubectl get nodes -o wide
NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME
desktop-control-plane Ready control-plane 28h v1.35.1 172.18.0.3 <none> Debian GNU/Linux 13 (trixie) 6.12.69-linuxkit containerd://2.2.1
desktop-worker Ready <none> 28h v1.35.1 172.18.0.6 <none> Debian GNU/Linux 13 (trixie) 6.12.69-linuxkit containerd://2.2.1
desktop-worker2 Ready <none> 28h v1.35.1 172.18.0.4 <none> Debian GNU/Linux 13 (trixie) 6.12.69-linuxkit containerd://2.2.1— 서비스 생성확인(포트번호 32497 확인)
Verify service creation (verify port number 32497)
MacBookAir nginx-test1 % kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 28h
nginx-deployment NodePort 10.96.49.237 <none> 80:32497/TCP 2m43s— 워커노드 접속 / Worker node connection
# worker node 1
MacBookAir nginx-test1 % docker exec -it desktop-worker bash
# worker node 2
MacBookAir nginx-test1 % docker exec -it desktop-worker2 bash— 워커 노드에서 nginx에 접속해 보기 / Trying to access nginx from a worker node
root@desktop-worker:/# curl 172.18.0.6:32497
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>
<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>
<p><em>Thank you for using nginx.</em></p>
</body>
</html>
— 워커 노드2는 아래처럼 접속합니다. / Worker Node 2 connects as follows.
# curl 172.18.0.4:32497👉🏻브라우저 접속하기 / Access browser
✔️ 터미널에서 8080포트로 NodePort 80포트와 연결
Connect NodePort 80 to port 8080 in the terminal
MacBookAir nginx-test1 % kubectl port-forward svc/nginx-deployment 8080:80
Forwarding from 127.0.0.1:8080 -> 80
Forwarding from [::1]:8080 -> 80✔️ 브라우저에서 localhost:8080으로 접속하면 “Welcome to nginx”화면을 볼 수 있습니다.
If you access localhost:8080 in your browser, you can see the “Welcome to nginx” screen.
