Kubernetes

安装

安装 kubectl

sudo apt-get update
# apt-transport-https 可以是一个虚拟包；如果是这样，你可以跳过这个包
sudo apt-get install -y apt-transport-https ca-certificates curl gnupg

curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.34/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg
sudo chmod 644 /etc/apt/keyrings/kubernetes-apt-keyring.gpg # allow unprivileged APT programs to read this keyring

echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.34/deb/ /' | sudo tee /etc/apt/sources.list.d/kubernetes.list
sudo chmod 644 /etc/apt/sources.list.d/kubernetes.list   # 有助于让诸如 command-not-found 等工具正常工作

sudo apt-get update
sudo apt-get install -y kubectl

安装 minikube

minikube start | minikube

curl -LO https://storage.googleapis.com/minikube/releases/latest/minikube_latest_arm64.deb
sudo dpkg -i minikube_latest_arm64.deb

sudo usermod -aG docker $USER && newgrp docker

minikube start

kubectl cluster-info

kubectl get nodes

应该看到类似下面的输出：

NAME       STATUS   ROLES    AGE   VERSION
minikube   Ready    control-plane   1m    v1.30.0

使用

启动

Debug

查看 Pod 日志：

kubectl logs nginx-xxxxxx

kubectl exec -it nginx-xxxxxx -- bash

kubectl describe pod nginx-xxxxxx

最常用来排查镜像拉取失败、CrashLoopBackOff 等。

kubectl delete deployment nginx

原理

Pod

ReplicaSet

Deployment（概念）

Service（概念）

部署验证 —— 部署第一个应用

Deployment

先创建一个 Deployment 文件：

nginx-deploy.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nginx
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
        - name: nginx
          image: nginx:latest
          ports:
            - containerPort: 80

kubectl apply -f nginx-deploy.yaml

kubectl get pods -l app=nginx

你应该看到类似：

nginx-5c68965b8f-bvzfm   1/1   Running   0   10s
nginx-5c68965b8f-k92lg   1/1   Running   0   10s

Service

创建文件：

nginx-svc.yaml

apiVersion: v1
kind: Service
metadata:
  name: nginx-svc
spec:
  type: NodePort
  selector:
    app: nginx
  ports:
    - port: 80
      targetPort: 80
      nodePort: 30080

部署：

kubectl apply -f nginx-svc.yaml

查看：

kubectl get svc

你会看到：

nginx-svc   NodePort   ...   80:30080/TCP

访问

curl http://localhost:30080

minikube service nginx-svc

它会自动打开浏览器访问。

滚动更新（Rolling Update）

修改 Deployment，将镜像改为：

image: nginx:1.21.0

重新 apply：

kubectl apply -f nginx-deploy.yaml

kubectl rollout status deployment/nginx

kubectl rollout undo deployment/nginx