kubernetes学习记录

原创于 2025-06-12 20:10:54 发布 · 191 阅读

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国内镜像源： registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/
 registry.cn-beijing.aliyuncs.com/kubesphereio/

一、Deployment

1.Pod是k8s中应用的最小单位

kubectl create ns hello
kubectl delete ns hello
kubectl get pod -A
kubectl run mynginx --image=nginx

# 查看default名称空间的Pod
kubectl get pod 
# 描述
kubectl describe pod 你自己的Pod名字
# 删除
kubectl delete pod Pod名字
# 查看Pod的运行日志
kubectl logs Pod名字

# 每个Pod - k8s都会分配一个ip
kubectl get pod -owide
# 使用Pod的ip+pod里面运行容器的端口
curl 192.168.169.136

# 集群中的任意一个机器以及任意的应用都能通过Pod分配的ip来访问这个Pod

2.Deployment

# 清除所有Pod，比较下面两个命令有何不同效果？
kubectl run mynginx --image=nginx

kubectl create deployment mytomcat --image=tomcat:8.5.68
# 自愈能力

#多副本能力
kubectl create deployment my-dep --image=nginx --replicas=3

3.扩缩容

kubectl scale --replicas=5 deployment/my-dep
kubectl edit deployment my-dep

#修改 replicas

4.滚动更新

kubectl set image deployment/my-dep nginx=nginx:1.16.1 --record
kubectl rollout status deployment/my-dep

5.版本回退

#历史记录
kubectl rollout history deployment/my-dep


#查看某个历史详情
kubectl rollout history deployment/my-dep --revision=2

#回滚(回到上次)
kubectl rollout undo deployment/my-dep

#回滚(回到指定版本)
kubectl rollout undo deployment/my-dep --to-revision=2

二、Service

将一组 Pods 公开为网络服务的抽象方法。

ClusterIP

#暴露Deploy
kubectl expose deployment my-dep --port=8000 --target-port=80

#使用标签检索Pod
kubectl get pod -l app=my-dep

NodePort

kubectl expose deployment my-dep --port=8000 --target-port=80 --type=NodePort

三、Ingress

1.下载

wget https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v0.47.0/deploy/static/provider/baremetal/deploy.yaml

#修改镜像
vi deploy.yaml
#将image的值改为如下值：
registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/ingress-nginx-controller:v0.46.0

# 检查安装的结果
kubectl get pod,svc -n ingress-nginx

# 最后别忘记把svc暴露的端口要放行

2.域名访问

apiVersion: networking.k8s.io/v1
kind: Ingress  
metadata:
  name: ingress-host-bar
spec:
  ingressClassName: nginx
  rules:
  - host: "hello.atguigu.com"
    http:
      paths:
      - pathType: Prefix
        path: "/"
        backend:
          service:
            name: hello-server
            port:
              number: 8000
  - host: "demo.atguigu.com"
    http:
      paths:
      - pathType: Prefix
        path: "/nginx"  # 把请求会转给下面的服务，下面的服务一定要能处理这个路径，不能处理就是404
        backend:
          service:
            name: nginx-demo  ## java，比如使用路径重写，去掉前缀nginx
            port:
              number: 8000

四、存储抽象

1.安装

#所有机器安装
yum install -y nfs-utils

2.主节点

#nfs主节点
echo "/nfs/data/ *(insecure,rw,sync,no_root_squash)" > /etc/exports

mkdir -p /nfs/data
systemctl enable rpcbind --now
systemctl enable nfs-server --now
#配置生效
exportfs -r

3.从节点

showmount -e 172.31.0.2

#执行以下命令挂载 nfs 服务器上的共享目录到本机路径 /root/nfsmount
mkdir -p /nfs/data

mount -t nfs 172.31.0.2:/nfs/data /nfs/data
# 写入一个测试文件
echo "hello nfs server" > /nfs/data/test.txt

4.pv&pvc

（1）创建pv池

#nfs主节点
mkdir -p /nfs/data/01
mkdir -p /nfs/data/02
mkdir -p /nfs/data/03

apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv01-10m
spec:
  capacity:
    storage: 10M
  accessModes:
    - ReadWriteMany
  storageClassName: nfs
  nfs:
    path: /nfs/data/01
    server: 172.31.0.2
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv02-1gi
spec:
  capacity:
    storage: 1Gi
  accessModes:
    - ReadWriteMany
  storageClassName: nfs
  nfs:
    path: /nfs/data/02
    server: 172.31.0.2
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: pv03-3gi
spec:
  capacity:
    storage: 3Gi
  accessModes:
    - ReadWriteMany
  storageClassName: nfs
  nfs:
    path: /nfs/data/03
    server: 172.31.0.2

（2）pvc创建与绑定

创建pvc

kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: nginx-pvc
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 200Mi
  storageClassName: nfs

创建pod绑定pvc

apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: nginx-deploy-pvc
  name: nginx-deploy-pvc
spec:
  replicas: 2
  selector:
    matchLabels:
      app: nginx-deploy-pvc
  template:
    metadata:
      labels:
        app: nginx-deploy-pvc
    spec:
      containers:
      - image: nginx
        name: nginx
        volumeMounts:
        - name: html
          mountPath: /usr/share/nginx/html
      volumes:
        - name: html
          persistentVolumeClaim:
            claimName: nginx-pvc

5.ConfigMap

抽取应用配置，并且可以自动更新

redis示例

把之前的配置文件创建为配置集

# 创建配置，redis保存到k8s的etcd；
kubectl create cm redis-conf --from-file=redis.conf

apiVersion: v1
data:    #data是所有真正的数据，key：默认是文件名   value：配置文件的内容
  redis.conf: |
    appendonly yes
kind: ConfigMap
metadata:
  name: redis-conf
  namespace: default

6.Secret

Secret 对象类型用来保存敏感信息，例如密码、OAuth 令牌和 SSH 密钥。将这些信息放在 secret 中比放在 Pod 的定义或者容器镜像中来说更加安全和灵活。

kubectl create secret docker-registry zaingray-docker \
--docker-username=zaingray \
--docker-password=Network919@ \
--docker-email=1093863953@qq.com

##命令格式
kubectl create secret docker-registry regcred \
  --docker-server=<你的镜像仓库服务器> \
  --docker-username=<你的用户名> \
  --docker-password=<你的密码> \
  --docker-email=<你的邮箱地址>

apiVersion: v1
kind: Pod
metadata:
  name: private-nginx
spec:
  containers:
  - name: mynginx
    image: zaingray/mynginx:v1.0
  imagePullSecrets:
  - name: zaingray-docker

7.配置默认存储

配置动态供应的默认存储类

## 创建了一个存储类
apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: nfs-storage
  annotations:
    storageclass.kubernetes.io/is-default-class: "true"
provisioner: k8s-sigs.io/nfs-subdir-external-provisioner
parameters:
  archiveOnDelete: "true"  ## 删除pv的时候，pv的内容是否要备份

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: nfs-client-provisioner
  labels:
    app: nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: default
spec:
  replicas: 1
  strategy:
    type: Recreate
  selector:
    matchLabels:
      app: nfs-client-provisioner
  template:
    metadata:
      labels:
        app: nfs-client-provisioner
    spec:
      serviceAccountName: nfs-client-provisioner
      containers:
        - name: nfs-client-provisioner
          image: registry.cn-hangzhou.aliyuncs.com/lfy_k8s_images/nfs-subdir-external-provisioner:v4.0.2
          # resources:
          #    limits:
          #      cpu: 10m
          #    requests:
          #      cpu: 10m
          volumeMounts:
            - name: nfs-client-root
              mountPath: /persistentvolumes
          env:
            - name: PROVISIONER_NAME
              value: k8s-sigs.io/nfs-subdir-external-provisioner
            - name: NFS_SERVER
              value: 172.31.0.2 ## 指定自己nfs服务器地址
            - name: NFS_PATH  
              value: /nfs/data  ## nfs服务器共享的目录
      volumes:
        - name: nfs-client-root
          nfs:
            server: 172.31.0.2
            path: /nfs/data
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: default
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: nfs-client-provisioner-runner
rules:
  - apiGroups: [""]
    resources: ["nodes"]
    verbs: ["get", "list", "watch"]
  - apiGroups: [""]
    resources: ["persistentvolumes"]
    verbs: ["get", "list", "watch", "create", "delete"]
  - apiGroups: [""]
    resources: ["persistentvolumeclaims"]
    verbs: ["get", "list", "watch", "update"]
  - apiGroups: ["storage.k8s.io"]
    resources: ["storageclasses"]
    verbs: ["get", "list", "watch"]
  - apiGroups: [""]
    resources: ["events"]
    verbs: ["create", "update", "patch"]
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: run-nfs-client-provisioner
subjects:
  - kind: ServiceAccount
    name: nfs-client-provisioner
    # replace with namespace where provisioner is deployed
    namespace: default
roleRef:
  kind: ClusterRole
  name: nfs-client-provisioner-runner
  apiGroup: rbac.authorization.k8s.io
---
kind: Role
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: leader-locking-nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: default
rules:
  - apiGroups: [""]
    resources: ["endpoints"]
    verbs: ["get", "list", "watch", "create", "update", "patch"]
---
kind: RoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: leader-locking-nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: default
subjects:
  - kind: ServiceAccount
    name: nfs-client-provisioner
    # replace with namespace where provisioner is deployed
    namespace: default
roleRef:
  kind: Role
  name: leader-locking-nfs-client-provisioner
  apiGroup: rbac.authorization.k8s.io