Kubernetes overview

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apiVersion: apps/v1 #旧版 K8s 使用 apps/v1beta1
kind: Deployment
metadata:
  name: hello-deploy
  namespace: dev
spec:
  replicas: 2
  selector: # Pod 所必须具备的标签
    matchLabels:
      app: hello-world
  minReadySeconds: 10
  strategy: # Pod 的更新操作
    type: RollingUpdate
    rollingUpdate:
      maxUnavailable: 1 # 不允许出现比期望状态指定的 Pod 数量少超过一个的情况
      maxSurge: 1 # 不允许出现比期望状态指定的 Pod 数量多超过一个的情况
  template: # 管理的 Pod 模板
    metadata:
      labels:
        app: hello-world # 这个 Label 与 Service 的 Label 筛选器是匹配的
    spec:
      containers:
        - name: hello-pod
          image: nginx:latest
          ports:
            - containerPort: 80
          volumeMounts:
            - mountPath: "/usr/share/nginx/html"
              name: nginx-pv-storage
      volumes:
        - name: nginx-pv-storage
          persistentVolumeClaim:
            claimName: nfs-pvc

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kubectl apply -f deploy.yml --record

kubectl rollout status deployment hello-deploy

kubectl get deploy

# 查看历史记录
kubectl rollout history deployment hello-deploy

# 回滚到版本1
kubectl rollout undo deployment hello-deploy --to-revision=1

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apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: tkb-sts
spec:
  replicas: 3
  selector:
    matchLabels:
      app: web
  serviceName: "dullahan"  # 与 handless Service 绑定
  template:
    metadata:
      labels:
        app: web
    spec:
      terminationGracePeriodSeconds: 10
      containers:
      - name: ctr-web
        image: nginx:latest
        ports:
        - containerPort: 80
          name: web
        volumeMounts:
        - name: webroot
          mountPath: /usr/share/nginx/html
  volumeClaimTemplates: # 用于在每次创建一个新的 Pod 副本的时候，自动创建一 个 PVC。
  - metadata:
      name: webroot
    spec:
      accessModes: [ "ReadWriteOnce" ]
      storageClassName: "flash"
      resources:
        requests:
          storage: 1Gi

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# StatefulSet 的应用是点对点发现的
# tkb-sts-0.dullahan.default.svc.cluster.local
<object-name>.<Service-name>.<namespace>.svc.cluster.local

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apiVersion: v1
kind: Service
metadata:
  name: hello-svc # 集群 DNS 中注册的名称
  labels:
    app: hello-world
spec:
  type: NodePort
  ports:
    - port: 8080
      nodePort: 30001
      protocol: TCP
  selector:
    app: hello-world # # Service 查找带有 app=hello-world 的 Pod

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# 查看 service
kubectl get svc

# 查看 service 后面的 endpoints
kubectl get ep

# 命令式方法部署Service
kubectl expose deployment web-deploy --name=hello-svc --target-port=8080 --type=NodePort

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# Headless Service for StatefulSet Pod DNS names
apiVersion: v1
kind: Service
metadata:
  name: dullahan   # 与 StatefulSet 的 ServiceName 关联
  labels:
    app: web
spec:
  ports:
  - port: 80
    name: web
  clusterIP: None
  selector:
    app: web

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apiVersion: v1
kind: PersistentVolume
metadata:
  name: nfs-pv
  labels:
    release: stable
spec:
  capacity:
    storage: 1024Gi
  volumeMode: Filesystem
  accessModes:
    - ReadWriteMany
  persistentVolumeReclaimPolicy: Retain
  storageClassName: nfs
  mountOptions:
    - hard
    - nfsvers=4.1
  nfs:
    path:  "/data/k8s_data"
    server: 192.168.0.100
    readOnly: false
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: nfs-pvc
spec:
  storageClassName: nfs
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 1024Gi

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kind: StorageClass
apiVersion: storage.k8s.io/v1
metadata:
  name: slow  # 由 PVC 引用
  annotations:
    storageclass.kubernetes.io/is-default-class: "true"
provisioner: kubernetes.io/gce-pd
parameters:
  type: pd-standard
reclaimPolicy: Retain
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: pv-ticket  # 由 PodSpec 引用
spec:
  accessModes:
  - ReadWriteOnce
  storageClassName: slow  # 匹配 SC 名称
  resources:
    requests:
      storage: 25Gi
---
apiVersion: v1
kind: Pod
metadata:
  name: class-pod
spec:
  volumes:
  - name: data
    persistentVolumeClaim:
      claimName: pv-ticket  # 匹配 PVC 名称
  containers:
  - name: ubuntu-ctr
    image: ubuntu:latest
    command:
    - /bin/bash
    - "-c"
    - "sleep 60m"
    volumeMounts:
    - mountPath: /data
      name: data

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# 删除顺序为 Pod，PVC，SC
kubectl delete Pod class-Pod
kubectl delete pvc pv-ticket
kubectl delete sc slow

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# 通过命令创建 configMap
kubectl create cm testmap1 \
--from-literal shortname=msb.com \
--from-literal longname=magicsandbox.com

kubectl create cm testmap2 --from-file cmfile.txt

# 通过声明创建 configMap
kind: ConfigMap
apiVersion: v1
metadata:
	name: test-conf
data:
	test.conf: |
		env = plex-test
		endpoint = 0.0.0.0:31001
		char = utf8
		vault = PLEX/test
		log-size = 512M

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apiVersion: v1
kind: Pod
metadata:
  labels:
    chapter: configmaps
  name: envpod
spec:
  restartPolicy: OnFailure
  containers:
    - name: ctr1
      image: busybox
      # 通过作为容器启动命令的参数
      command: [ "/bin/sh", "-c", "echo First name $(FIRSTNAME) last name $(LASTNAME)" ]
      env:
        - name: FIRSTNAME
          valueFrom:
            configMapKeyRef:
              name: multimap
              key: given
        - name: LASTNAME
          valueFrom:
            configMapKeyRef:
              name: multimap
              key: family