Kubernetes 开发概述

# 声明式配置示例
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-app
spec:
  replicas: 3
  selector:
    matchLabels:
      app: my-app
  template:
    metadata:
      labels:
        app: my-app
    spec:
      containers:
      - name: app
        image: myapp:v1.0
        ports:
        - containerPort: 8080

# 开发常用命令
kubectl create -f deployment.yaml    # 创建资源
kubectl apply -f deployment.yaml     # 声明式更新
kubectl get pods -w                  # 实时监控
kubectl logs -f deployment/my-app    # 查看日志
kubectl exec -it pod/my-pod -- /bin/bash  # 调试容器
kubectl port-forward svc/my-service 8080:80  # 端口转发

package main

import (
    "context"
    "fmt"
    metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
    "k8s.io/client-go/kubernetes"
    "k8s.io/client-go/rest"
)

func main() {
    // 创建客户端配置
    config, err := rest.InClusterConfig()
    if err != nil {
        panic(err.Error())
    }

    // 创建客户端
    clientset, err := kubernetes.NewForConfig(config)
    if err != nil {
        panic(err.Error())
    }

    // 列出所有 Pod
    pods, err := clientset.CoreV1().Pods("").List(context.TODO(), metav1.ListOptions{})
    if err != nil {
        panic(err.Error())
    }

    fmt.Printf("There are %d pods in the cluster\n", len(pods.Items))
}

# 初始化项目
operator-sdk init --domain example.com --repo github.com/example/my-operator

# 创建API
operator-sdk create api --group apps --version v1 --kind MyApp --resource --controller

# 构建和部署
make docker-build docker-push IMG=myregistry/my-operator:v1.0.0
make deploy IMG=myregistry/my-operator:v1.0.0

# 初始化项目
kubebuilder init --domain example.com --repo github.com/example/my-controller

# 创建API
kubebuilder create api --group apps --version v1 --kind MyApp --resource --controller

# 运行测试
make test

# 启动Minikube
minikube start --driver=docker --kubernetes-version=v1.28.0

# 启用插件
minikube addons enable ingress
minikube addons enable dashboard

# 获取集群信息
kubectl cluster-info

# kind-config.yaml
kind: Cluster
apiVersion: kind.x-k8s.io/v1alpha4
nodes:
- role: control-plane
  kubeadmConfigPatches:
  - |
    kind: InitConfiguration
    nodeRegistration:
      kubeletExtraArgs:
        node-labels: "ingress-ready=true"
  extraPortMappings:
  - containerPort: 80
    hostPort: 80
    protocol: TCP
  - containerPort: 443
    hostPort: 443
    protocol: TCP
- role: worker
- role: worker

# 创建集群
kind create cluster --config kind-config.yaml --name my-cluster

# 加载镜像到集群
kind load docker-image my-app:latest --name my-cluster

// .devcontainer/devcontainer.json
{
  "name": "Kubernetes Development",
  "image": "mcr.microsoft.com/devcontainers/go:1.21",
  "features": {
    "ghcr.io/devcontainers/features/docker-in-docker:2": {},
    "ghcr.io/devcontainers/features/kubectl-helm-minikube:1": {}
  },
  "customizations": {
    "vscode": {
      "extensions": [
        "ms-kubernetes-tools.vscode-kubernetes-tools",
        "ms-vscode.vscode-json",
        "golang.Go"
      ]
    }
  },
  "postCreateCommand": "minikube start"
}

├── api/
│   └── v1alpha1/          # API 定义
├── controllers/           # 控制器逻辑
├── config/               # 配置管理
│   ├── crd/             # CRD 定义
│   ├── rbac/            # RBAC 配置
│   └── manager/         # Manager 配置
├── hack/                # 构建脚本
├── internal/            # 内部包
├── pkg/                 # 可重用包
├── test/                # 测试代码
│   ├── e2e/            # 端到端测试
│   └── integration/    # 集成测试
├── Dockerfile          # 容器构建
├── Makefile           # 构建配置
├── go.mod             # Go 模块
└── main.go            # 程序入口

# Chart.yaml
apiVersion: v2
name: my-operator
description: A Kubernetes operator for managing MyApp
type: application
version: 1.2.3          # Chart 版本
appVersion: "v1.2.3"    # 应用版本