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Kind로 Kubernetes Cluster 배포하기 [Cilium Study 5주차]

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By KKamJi
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Kind Architecture

Kind는 Kubernetes in Docker의 줄임말로, Docker 컨테이너를 노드로 사용해 로컬에서 Kubernetes Cluster를 실행하기 위한 도구입니다. Kubernetes Cluster를 테스트하기 위해 설계되었지만, 로컬 개발이나 CI 과정에서도 사용될 수 있습니다.

이번 포스트에서는 Kind에 대해 알아보고, Kind를 사용해 Cluster를 생성해보도록 하겠습니다.

관련 글

  1. Vagrant와 VirtualBox로 Kubernetes Cluster 구축하기 [Cilium Study 1주차]
  2. Flannel CNI 배포하기 [Cilium Study 1주차]
  3. Cilium CNI 알아보기 [Cilium Study 1주차]
  4. Cilium 구성요소 & 배포하기 (kube-proxy replacement) [Cilium Study 1주차]
  5. Cilium Hubble 알아보기 [Cilium Study 2주차]
  6. Cilium & Hubble Command Cheat Sheet [Cilium Study 2주차]
  7. Star Wars Demo와 함께 Cilium Network Policy 알아보기 [Cilium Study 2주차]
  8. Hubble Exporter와 Dynamic Exporter Configuration [Cilium Study 2주차]
  9. Monitoring VS Observability + SLI/SLO/SLA 알아보기 [Cilium Study 2주차]
  10. Cilium Metric Monitoring with Prometheus + Grafana [Cilium Study 2주차]
  11. Cilium Log Monitoring with Grafana Loki & Grafana Alloy [Cilium Study 2주차]
  12. IPAM 개념 및 Kubernetes Host Scope -> Cluster Scope Migration 실습 [Cilium Study 3주차]
  13. Cilium Network Routing 이해하기 – Encapsulation과 Native Routing 비교 [Cilium Study 3주차]
  14. Cilium Native Routing 통신 확인 및 문제 해결 – Static Route & BGP [Cilium Study 4주차]
  15. Cilium BGP Control Plane [Cilium Study 5주차]
  16. Cilium Service LoadBalancer BGP Advertisement & ExternalTrafficPolicy [Cilium Study 5주차]
  17. Kind로 Kubernetes Cluster 배포하기 [Cilium Study 5주차] (현재 글)
  18. Cilium Cluster Mesh [Cilium Study 5주차]
  19. Cilium Service Mesh [Cilium Study 6주차]

1. 사전 조건

2. Kind 설치 

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# For AMD64 / x86_64
[ $(uname -m) = x86_64 ] && curl -Lo ./kind https://kind.sigs.k8s.io/dl/v0.29.0/kind-linux-amd64
# For ARM64
[ $(uname -m) = aarch64 ] && curl -Lo ./kind https://kind.sigs.k8s.io/dl/v0.29.0/kind-linux-arm64
chmod +x ./kind
sudo mv ./kind /usr/local/bin/kind

Kind Docs - Quick Start

3. Kind로 Kubernetes Cluster 배포

Default 세팅으로 Kubernetes Cluster를 배포해보도록 하겠습니다. kind로 배포한 Cluster의 Kubeconfig Context는 자동으로 kind 명령을 날린 호스트의 Kubeconfig에 merge됩니다.

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################################
# Cluster 배포 전 컨테이너 확인
################################
docker ps
# CONTAINER ID   IMAGE     COMMAND   CREATED   STATUS    PORTS     NAMES

################################
# Cluster 생성
################################
kind create cluster
# Creating cluster "kind" ...
#  ✓ Ensuring node image (kindest/node:v1.33.1) 🖼 
#  ✓ Preparing nodes 📦  
#  ✓ Writing configuration 📜 
#  ✓ Starting control-plane 🕹️ 
#  ✓ Installing CNI 🔌 
#  ✓ Installing StorageClass 💾 
# Set kubectl context to "kind-kind"
# You can now use your cluster with:

# kubectl cluster-info --context kind-kind

# Have a question, bug, or feature request? Let us know! https://kind.sigs.k8s.io/#community 🙂

################################
# Kind Cluster 확인
################################
kind get clusters  
# kind

4. Kubernetes Cluster 배포 확인 

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################################
# kubectl context 확인
################################
kubectl config get-contexts
CURRENT   NAME        CLUSTER          AUTHINFO           NAMESPACE
*         kind-kind   kind-kind        kind-kind          

################################
# Node 정보 확인
################################
kubectl get node -o wide
# NAME                 STATUS     ROLES           AGE   VERSION   INTERNAL-IP   EXTERNAL-IP   OS-IMAGE                         KERNEL-VERSION                     CONTAINER-RUNTIME
# kind-control-plane   NotReady   control-plane   20s   v1.33.1   172.18.0.2    <none>        Debian GNU/Linux 12 (bookworm)   6.6.87.2-microsoft-standard-WSL2   containerd://2.1.1

################################
# Pod 정보 확인
################################
kubectl get pod -A -o wide
# NAMESPACE            NAME                                         READY   STATUS    RESTARTS   AGE   IP           NODE                 NOMINATED NODE   READINESS GATES
# kube-system          coredns-674b8bbfcf-cxjzl                     1/1     Running   0          31s   10.244.0.2   kind-control-plane   <none>           <none>
# kube-system          coredns-674b8bbfcf-gwrcg                     1/1     Running   0          31s   10.244.0.3   kind-control-plane   <none>           <none>
# kube-system          etcd-kind-control-plane                      1/1     Running   0          37s   172.18.0.2   kind-control-plane   <none>           <none>
# kube-system          kindnet-ljlj2                                1/1     Running   0          31s   172.18.0.2   kind-control-plane   <none>           <none>
# kube-system          kube-apiserver-kind-control-plane            1/1     Running   0          37s   172.18.0.2   kind-control-plane   <none>           <none>
# kube-system          kube-controller-manager-kind-control-plane   1/1     Running   0          37s   172.18.0.2   kind-control-plane   <none>           <none>
# kube-system          kube-proxy-pvrxh                             1/1     Running   0          31s   172.18.0.2   kind-control-plane   <none>           <none>
# kube-system          kube-scheduler-kind-control-plane            1/1     Running   0          37s   172.18.0.2   kind-control-plane   <none>           <none>
# local-path-storage   local-path-provisioner-7dc846544d-sp94l      1/1     Running   0          31s   10.244.0.4   kind-control-plane   <none>           <none>

################################
# Component Status 확인
################################
kubectl get --raw '/healthz?verbose' | sed 's/; /\n/g'

# [+]ping ok
# [+]log ok
# [+]etcd ok
# [+]poststarthook/start-apiserver-admission-initializer ok
# [+]poststarthook/generic-apiserver-start-informers ok
# [+]poststarthook/priority-and-fairness-config-consumer ok
# [+]poststarthook/priority-and-fairness-filter ok
# [+]poststarthook/storage-object-count-tracker-hook ok
# [+]poststarthook/start-apiextensions-informers ok
# [+]poststarthook/start-apiextensions-controllers ok
# [+]poststarthook/crd-informer-synced ok
# [+]poststarthook/start-system-namespaces-controller ok
# [+]poststarthook/start-cluster-authentication-info-controller ok
# [+]poststarthook/start-kube-apiserver-identity-lease-controller ok
# [+]poststarthook/start-kube-apiserver-identity-lease-garbage-collector ok
# [+]poststarthook/start-legacy-token-tracking-controller ok
# [+]poststarthook/start-service-ip-repair-controllers ok
# [+]poststarthook/rbac/bootstrap-roles ok
# [+]poststarthook/scheduling/bootstrap-system-priority-classes ok
# [+]poststarthook/priority-and-fairness-config-producer ok
# [+]poststarthook/bootstrap-controller ok
# [+]poststarthook/start-kubernetes-service-cidr-controller ok
# [+]poststarthook/aggregator-reload-proxy-client-cert ok
# [+]poststarthook/start-kube-aggregator-informers ok
# [+]poststarthook/apiservice-status-local-available-controller ok
# [+]poststarthook/apiservice-status-remote-available-controller ok
# [+]poststarthook/apiservice-registration-controller ok
# [+]poststarthook/apiservice-discovery-controller ok
# [+]poststarthook/kube-apiserver-autoregistration ok
# [+]autoregister-completion ok
# [+]poststarthook/apiservice-openapi-controller ok
# [+]poststarthook/apiservice-openapiv3-controller ok
# healthz check passed

################################
# Docker Container 확인
################################
docker ps
# CONTAINER ID   IMAGE                  COMMAND                  CREATED         STATUS         PORTS                       NAMES
# 72fe47021619   kindest/node:v1.33.1   "/usr/local/bin/entr…"   3 minutes ago   Up 3 minutes   127.0.0.1:39917->6443/tcp   kind-control-plane

################################
# Docker Network 확인
################################
docker inspect kind | jq '.[0].IPAM.Config'
[
  {
    "Subnet": "172.18.0.0/16",
    "Gateway": "172.18.0.1"
  },
  {
    "Subnet": "fc00:f853:ccd:e793::/64",
    "Gateway": "fc00:f853:ccd:e793::1"
  }
]

################################
# Control Plane Container에서 포트 바인딩 확인
################################
docker exec -it kind-control-plane ss -tnlp | grep 6443
LISTEN 0      4096               *:6443             *:*    users:(("kube-apiserver",pid=554,fd=3))

5. Pod 생성 및 통신 확인

Kind의 Default Setting으로 Control Plane Node 만 존재할 경우, Control Plane Node에 Pod가 스케줄될 수 있도록 NoSchedule taint가 제거되어 있습니다.

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################################
# Node Taint 확인
################################
kubectl describe node | grep -i Taints
# Taints:             <none>

################################
# Sample Application 배포 (webpod Deployment + Service)
################################
cat << EOF | kubectl apply -f -
apiVersion: apps/v1
kind: Deployment
metadata:
  name: webpod
spec:
  replicas: 1
  selector:
    matchLabels:
      app: webpod
  template:
    metadata:
      labels:
        app: webpod
    spec:
      affinity:
        podAntiAffinity:
          requiredDuringSchedulingIgnoredDuringExecution:
          - labelSelector:
              matchExpressions:
              - key: app
                operator: In
                values: ["webpod"]
            topologyKey: "kubernetes.io/hostname"
      containers:
      - name: webpod
        image: traefik/whoami
        ports:
        - containerPort: 80
---
apiVersion: v1
kind: Service
metadata:
  name: webpod
  labels:
    app: webpod
spec:
  selector:
    app: webpod
  ports:
  - protocol: TCP
    port: 80
    targetPort: 80
  type: ClusterIP
EOF

###############################################
# curl-pod 배포 (k8s-ctr에 고정)
###############################################
cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: Pod
metadata:
  name: curl-pod
  labels:
    app: curl
spec:
  containers:
  - name: curl
    image: nicolaka/netshoot
    command: ["tail"]
    args: ["-f", "/dev/null"]
  terminationGracePeriodSeconds: 0
EOF

###############################################
# Pod Status 확인
###############################################
kubectl get deploy,po,svc -o wide
# NAME                     READY   UP-TO-DATE   AVAILABLE   AGE     CONTAINERS   IMAGES           SELECTOR
# deployment.apps/webpod   1/1     1            1           2m43s   webpod       traefik/whoami   app=webpod

# NAME                          READY   STATUS    RESTARTS   AGE     IP           NODE                 NOMINATED NODE   READINESS GATES
# pod/curl-pod                  1/1     Running   0          2m43s   10.244.0.7   kind-control-plane   <none>           <none>
# pod/webpod-74f6f7bd86-s72mc   1/1     Running   0          2m43s   10.244.0.6   kind-control-plane   <none>           <none>

# NAME                 TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)   AGE     SELECTOR
# service/kubernetes   ClusterIP   10.96.0.1      <none>        443/TCP   15m     <none>
# service/webpod       ClusterIP   10.96.187.29   <none>        80/TCP    2m43s   app=webpod

###############################################
# 통신 확인
###############################################
kubectl exec -it curl-pod -- curl -s http://webpod.default.svc.cluster.local

# Hostname: webpod-74f6f7bd86-s72mc
# IP: 127.0.0.1
# IP: ::1
# IP: 10.244.0.6
# IP: fe80::9004:12ff:fee7:117e
# RemoteAddr: 10.244.0.7:47124
# GET / HTTP/1.1
# Host: webpod.default.svc.cluster.local
# User-Agent: curl/8.14.1
# Accept: */*

6. Cluster 삭제 및 Context 확인 

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################################
# 클러스터 확인
################################
kind get clusters 
# kind

################################
# 클러스터 삭제
################################
# Default Cluster의 경우 이름을 따로 지정해주지 않아도 됨
kind delete cluster --name kind
# Deleting cluster "kind" ...
# Deleted nodes: ["kind-control-plane"]

################################
# Docker Container 확인
################################
docker ps                                                       
# CONTAINER ID   IMAGE     COMMAND   CREATED   STATUS    PORTS     NAMES

################################
# Kind Cluster의 Context 확인 (삭제됨)
################################
kubectl config get-contexts                                                 
# CURRENT   NAME     CLUSTER          AUTHINFO           NAMESPACE

7. Reference

궁금하신 점이나 추가해야 할 부분은 댓글이나 아래의 링크를 통해 문의해주세요.
Written with KKamJi

Kubernetes, Cilium
kubernetes devops cilium cilium-study kind
This post is licensed under CC BY 4.0 by the author.