Kubectl 命令技巧大全

# Bash
source <(kubectl completion bash)
echo "source <(kubectl completion bash)" >> ~/.bashrc

# Zsh  
source <(kubectl completion zsh)
echo "source <(kubectl completion zsh)" >> ~/.zshrc

# Fish
kubectl completion fish | source

# 查看当前配置
kubectl config view

# 合并多个 kubeconfig 文件
KUBECONFIG=~/.kube/config:~/.kube/config2 kubectl config view

# 查看当前上下文
kubectl config current-context

# 切换上下文
kubectl config use-context my-cluster-name

# 列出所有上下文
kubectl config get-contexts

# 设置集群凭据
kubectl config set-credentials kubeuser/foo.kubernetes.com \
  --username=kubeuser --password=kubepassword

# 设置上下文
kubectl config set-context my-context \
  --cluster=my-cluster \
  --user=my-user \
  --namespace=my-namespace

# 从文件创建资源
kubectl apply -f ./manifest.yaml
kubectl apply -f ./dir/                    # 应用目录下所有文件
kubectl apply -f https://example.com/manifest.yaml

# 命令式创建（适用于快速测试）
kubectl create deployment nginx --image=nginx:1.21
kubectl create service clusterip my-svc --tcp=80:80

# 获取资源文档
kubectl explain pod.spec.containers
kubectl explain deployment --recursive

# 从标准输入创建多个资源
cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: ConfigMap
metadata:
  name: my-config
data:
  config.yaml: |
    key: value
---
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: nginx:1.21
        ports:
        - containerPort: 80
EOF

# 基本查询
kubectl get pods                           # 当前命名空间的 pods
kubectl get pods -A                        # 所有命名空间的 pods  
kubectl get pods -o wide                   # 显示更多信息
kubectl get pods --show-labels             # 显示标签

# 按标签筛选
kubectl get pods -l app=nginx
kubectl get pods -l 'environment in (production,staging)'

# 排序
kubectl get pods --sort-by=.metadata.creationTimestamp
kubectl get pods --sort-by=.status.startTime

# JSONPath 查询
kubectl get pods -o jsonpath='{.items[*].metadata.name}'
kubectl get nodes -o jsonpath='{.items[*].status.addresses[?(@.type=="InternalIP")].address}'

# 自定义列输出
kubectl get pods -o custom-columns=NAME:.metadata.name,STATUS:.status.phase

# 监听资源变化
kubectl get pods --watch
kubectl get events --watch --field-selector involvedObject.name=my-pod

# 详细描述
kubectl describe pod my-pod
kubectl describe node my-node

# 声明式更新（推荐）
kubectl apply -f updated-manifest.yaml

# 直接编辑资源
kubectl edit deployment my-deployment

# 打补丁更新
kubectl patch deployment my-deployment -p '{"spec":{"replicas":5}}'
kubectl patch pod my-pod --type='json' -p='[{"op": "replace", "path": "/spec/containers/0/image", "value":"nginx:1.22"}]'

# 标签和注解
kubectl label pods my-pod version=v2
kubectl annotate pods my-pod description="Updated pod"

# 扩缩容
kubectl scale deployment my-deployment --replicas=5
kubectl autoscale deployment my-deployment --min=2 --max=10 --cpu-percent=80

# 删除指定资源
kubectl delete pod my-pod
kubectl delete -f manifest.yaml

# 批量删除
kubectl delete pods,services -l app=my-app
kubectl delete all -l app=my-app              # 删除常见资源类型

# 强制删除
kubectl delete pod my-pod --force --grace-period=0

# 清空命名空间
kubectl delete all --all -n my-namespace

# 查看日志
kubectl logs my-pod                         # 单容器 pod
kubectl logs my-pod -c container-name       # 多容器 pod
kubectl logs my-pod --previous              # 查看上一个容器的日志
kubectl logs -f my-pod                      # 流式日志
kubectl logs my-pod --since=1h              # 最近1小时的日志

# 执行命令
kubectl exec my-pod -- ls /app
kubectl exec my-pod -c my-container -- sh
kubectl exec -it my-pod -- /bin/bash        # 交互式shell

# 端口转发
kubectl port-forward pod/my-pod 8080:80
kubectl port-forward service/my-service 8080:80

# 文件传输
kubectl cp my-pod:/path/to/file ./local-file
kubectl cp ./local-file my-pod:/path/to/file

# 资源使用情况
kubectl top pod my-pod
kubectl top pod --containers
kubectl top node

# 节点管理
kubectl get nodes
kubectl describe node my-node
kubectl cordon my-node                      # 标记不可调度
kubectl drain my-node --ignore-daemonsets   # 驱逐Pod进行维护
kubectl uncordon my-node                    # 恢复调度

# 污点管理
kubectl taint nodes my-node key=value:NoSchedule
kubectl taint nodes my-node key=value:NoSchedule-  # 移除污点

# 集群信息
kubectl cluster-info
kubectl cluster-info dump
kubectl version
kubectl api-resources                       # 查看所有资源类型
kubectl api-versions                        # 查看API版本

# 使用字段选择器
kubectl get pods --field-selector status.phase=Running
kubectl get events --field-selector type=Warning

# 组合查询
kubectl get pods -l app=nginx --field-selector status.phase=Running

# 输出到文件
kubectl get pods -o yaml > pods-backup.yaml
kubectl get all -o yaml --export > cluster-backup.yaml

# 监控资源变化
kubectl get pods --watch-only
kubectl get events --watch --field-selector involvedObject.name=my-pod