1
# API Server 是集群的统一入口
2
# 所有组件都通过它交互
3

4
apiVersion: v1
5
kind: Pod
6
metadata:
7
  name: nginx
8
spec:
9
  containers:
10
    - name: nginx
11
      image: nginx:1.25

1
# API Server 特性
2
# 1. 认证鉴权
3
kubectl get pods --token=<token>
4

5
# 2. 准入控制
6
# - LimitRanger
7
# - ResourceQuota
8
# - MutatingWebhook
9

10
# 3. 存储缓存
11
# watch 机制通知变更

1
# etcd 是一致性键值存储
2
# 存储 Kubernetes 所有状态数据
3

4
# 重要数据
5
# - Pod 状态
6
# - Service 端点
7
# - ConfigMap/Secret
8
# - 调度信息
9

10
# 备份命令
11
ETCDCTL_API=3 etcdctl snapshot save backup.db \
12
  --endpoints=https://127.0.0.1:2379 \
13
  --cacert=/etc/kubernetes/pki/etcd/ca.crt \
14
  --cert=/etc/kubernetes/pki/etcd/server.crt \
15
  --key=/etc/kubernetes/pki/etcd/server.key

1
# Scheduler 负责选择最佳 Node 运行 Pod
2

3
apiVersion: v1
4
kind: Pod
5
metadata:
6
  name: nginx
7
spec:
8
  # 调度策略
9
  nodeSelector:
10
    disktype: ssd
11
  affinity:
12
    nodeAffinity:
13
      preferredDuringSchedulingIgnoredDuringExecution:
14
        - weight: 1
15
          preference:
16
            matchExpressions:
17
              - key: memory
18
                operator: GreaterThan
19
                values:
20
                  - "8Gi"
21
  tolerations:
22
    - key: "node.kubernetes.io/not-ready"
23
      operator: "Exists"
24
      effect: "NoSchedule"

1
# 运行所有 Kubernetes 控制器
2

3
# 控制器列表
4
# - ReplicaSet Controller
5
# - Deployment Controller
6
# - DaemonSet Controller
7
# - StatefulSet Controller
8
# - Job Controller
9
# - CronJob Controller
10
# - Service Controller
11
# - Endpoint Controller
12
# - Namespace Controller
13
# - Node Controller

1
# kubelet 是 Node 上的主要代理
2
# 1. 向 API Server 注册 Node
3
# 2. 创建/销毁 Pod
4
# 3. 监控容器健康
5
# 4. 报告资源使用
6

7
# kubelet 不会管理非 Kubernetes 创建的容器

1
# kube-proxy 维护网络规则
2
# 实现 Service 的负载均衡
3

4
# 模式
5
# 1. iptables (默认) - 规则匹配
6
# 2. IPVS - 适合大规模集群
7
# 3. Userspace - 旧模式，不推荐
8

9
# 查看 iptables 规则
10
iptables -L -t nat | grep KUBE-SERVICES

1
# 支持的容器运行时
2
# 1. containerd (推荐)
3
# 2. CRI-O
4
# 3. Docker (deprecated)
5

6
# CRI: Container Runtime Interface
7
# kubelet 通过 CRI 与容器运行时通信

1
apiVersion: v1
2
kind: Pod
3
metadata:
4
  name: nginx-pod
5
spec:
6
  # 容器配置
7
  containers:
8
    - name: nginx
9
      image: nginx:1.25
10
      ports:
11
        - containerPort: 80
12
          protocol: TCP
13

14
      # 资源请求和限制
15
      resources:
16
        requests:
17
          memory: "64Mi"
18
          cpu: "250m"
19
        limits:
20
          memory: "128Mi"
21
          cpu: "500m"
22

23
      # 环境变量
24
      env:
25
        - name: DB_HOST
26
          value: "db-service"
27
        - name: DB_PASSWORD
28
          valueFrom:
29
            secretKeyRef:
30
              name: db-secrets
31
              key: password
32

33
      # 探针配置
34
      livenessProbe:
35
        httpGet:
36
          path: /healthz
37
          port: 80
38
        initialDelaySeconds: 10
39
        periodSeconds: 5
40

41
      readinessProbe:
42
        httpGet:
43
          path: /ready
44
          port: 80
45
        initialDelaySeconds: 5
46
        periodSeconds: 3
47

48
      startupProbe:
49
        httpGet:
50
          path: /healthz
51
          port: 80
52
        failureThreshold: 30
53
        periodSeconds: 10

1
# 探针配置示例
2
livenessProbe:
3
  httpGet:
4
    path: /healthz
5
    port: 8080
6
  initialDelaySeconds: 10 # 启动后多久开始
7
  periodSeconds: 5 # 检查间隔
8
  timeoutSeconds: 3 # 超时时间
9
  successThreshold: 1 # 连续成功次数
10
  failureThreshold: 3 # 连续失败次数
11

12
# TCP 检查
13
readinessProbe:
14
  tcpSocket:
15
    port: 5432
16

17
# 执行命令
18
startupProbe:
19
  exec:
20
    command:
21
      - cat
22
      - /tmp/healthy

1
apiVersion: apps/v1
2
kind: Deployment
3
metadata:
4
  name: nginx-deployment
5
spec:
6
  replicas: 3
7

8
  # 选择器
9
  selector:
10
    matchLabels:
11
      app: nginx
12

13
  # 更新策略
14
  strategy:
15
    type: RollingUpdate
16
    rollingUpdate:
17
      maxSurge: 1 # 最多超出副本数
18
      maxUnavailable: 0 # 最少可用副本数
19

20
  # Pod 模板
21
  template:
22
    metadata:
23
      labels:
24
        app: nginx
25
    spec:
26
      containers:
27
        - name: nginx
28
          image: nginx:1.25
29
          ports:
30
            - containerPort: 80

1
# 更新镜像
2
kubectl set image deployment/nginx-deployment nginx=nginx:1.26
3

4
# 查看滚动更新状态
5
kubectl rollout status deployment/nginx-deployment
6

7
# 回滚
8
kubectl rollout undo deployment/nginx-deployment
9
kubectl rollout undo deployment/nginx-deployment --to-revision=2
10

11
# 暂停/恢复
12
kubectl rollout pause deployment/nginx-deployment
13
kubectl rollout resume deployment/nginx-deployment
14

15
# 查看历史版本
16
kubectl rollout history deployment/nginx-deployment

1
apiVersion: autoscaling/v2
2
kind: HorizontalPodAutoscaler
3
metadata:
4
  name: nginx-hpa
5
spec:
6
  scaleTargetRef:
7
    apiVersion: apps/v1
8
    kind: Deployment
9
    name: nginx-deployment
10
  minReplicas: 2
11
  maxReplicas: 10
12
  metrics:
13
    - type: Resource
14
      resource:
15
        name: cpu
16
        target:
17
          type: Utilization
18
          averageUtilization: 70
19
    - type: Resource
20
      resource:
21
        name: memory
22
        target:
23
          type: Utilization
24
          averageUtilization: 80

1
# 手动伸缩
2
kubectl scale deployment/nginx-deployment --replicas=5
3

4
# 查看 HPA
5
kubectl get hpa
6
kubectl describe hpa nginx-hpa