Kubernetes

k8s资源对象

本文主要是介绍k8s资源对象,对大家解决编程问题具有一定的参考价值,需要的程序猿们随着小编来一起学习吧!

  什么是资源对象?

  所谓资源对象是指在k8s上创建的资源实例;即通过apiserver提供的各资源api接口(可以理解为各种资源模板),使用yaml文件或者命令行的方式向对应资源api接口传递参数赋值实例化的结果;比如我们在k8s上创建一个pod,那么我们就需要通过给apiserver交互,传递创建pod的相关参数,让apiserver拿着这些参数去实例化一个pod的相关信息存放在etcd中,然后再由调度器进行调度,由node节点的kubelet执行创建pod;简单讲资源对象就是把k8s之上的api接口进行实例化的结果;

  k8s逻辑运行环境

  提示:k8s运行环境如上,k8s能够将多个node节点的底层提供的资源(如内存,cpu,存储,网络等)逻辑的整合成一个大的资源池,统一由k8s进行调度编排;用户只管在k8s上创建各种资源即可,创建完成的资源是通过k8s统一编排调度,用户无需关注具体资源在那个node上运行,也无需关注node节点资源情况;

  k8s的设计理念——分层架构

  k8s的设计理念——API设计原则

  1、所有API应该是声明式的;

  2、API对象是彼此互补而且可组合的,即“高内聚,松耦合”;

  3、高层API以操作意图为基础设计;

  4、低层API根据高层API的控制需要设计;

  5、尽量避免简单封装,不要有在外部API无法显式知道的内部隐藏的机制;

  6、API操作复杂度与对象数量成正比;

  7、API对象状态不能依赖于网络连接状态;

  8、尽量避免让操作机制依赖于全局状态,因为在分布式系统中要保证全局状态的同步是非常困难的;

  kubernetes API简介

  提示:在k8s上api分内置api和自定义api;所谓内置api是指部署好k8s集群后自带的api接口;自定义api也称自定义资源(CRD,Custom Resource Definition),部署好k8s之后,通过安装其他组件等方式扩展出来的api;

  apiserver资源组织逻辑

  提示:apiserver对于不同资源是通过分类,分组,分版本的方式逻辑组织的,如上图所示;

  k8s内置资源对象简介

  k8s资源对象操作命令

  资源配置清单必需字段

  1、apiVersion - 创建该对象所使用的Kubernetes API的版本;

  2、kind - 想要创建的对象的类型;

  3、metadata - 定义识别对象唯一性的数据,包括一个name名称 、可选的namespace,默认不写就是default名称空间;

  4、spec:定义资源对象的详细规范信息(统一的label标签、容器名称、镜像、端口映射等),即用户期望对应资源处于什么状态;

  5、status(Pod创建完成后k8s自动生成status状态),该字段信息由k8s自动维护,用户无需定义,即对应资源的实际状态;

  Pod资源对象

  提示:pod是k8s中最小控制单元,一个pod中可以运行一个或多个容器;一个pod的中的容器是一起调度,即调度的最小单位是pod;pod的生命周期是短暂的,不会自愈,是用完就销毁的实体;一般我们通过Controller来创建和管理pod;使用控制器创建的pod具有自动恢复功能,即pod状态不满足用户期望状态,对应控制器会通过重启或重建的方式,让对应pod状态和数量始终和用户定义的期望状态一致;

  示例:自主式pod配置清单

apiVersion: v1
kind: Pod
metadata:
  name: "pod-demo"
  namespace: default
  labels:
    app: "pod-demo"
spec:
  containers:
  - name: pod-demo
    image: "harbor.ik8s.cc/baseimages/nginx:v1"
    ports:
    - containerPort:  80
      name:  http
    volumeMounts:
    - name: localtime
      mountPath: /etc/localtime
  volumes:
    - name: localtime
      hostPath:
        path: /usr/share/zoneinfo/Asia/Shanghai

  应用配置清单

root@k8s-deploy:/yaml# kubectl get pods 
NAME        READY   STATUS    RESTARTS        AGE
net-test1   1/1     Running   2 (4m35s ago)   7d7h
test        1/1     Running   4 (4m34s ago)   13d
test1       1/1     Running   4 (4m35s ago)   13d
test2       1/1     Running   4 (4m35s ago)   13d
root@k8s-deploy:/yaml# kubectl apply -f pod-demo.yaml
pod/pod-demo created
root@k8s-deploy:/yaml# kubectl get pods 
NAME        READY   STATUS              RESTARTS        AGE
net-test1   1/1     Running             2 (4m47s ago)   7d7h
pod-demo    0/1     ContainerCreating   0               4s
test        1/1     Running             4 (4m46s ago)   13d
test1       1/1     Running             4 (4m47s ago)   13d
test2       1/1     Running             4 (4m47s ago)   13d
root@k8s-deploy:/yaml# kubectl get pods 
NAME        READY   STATUS    RESTARTS        AGE
net-test1   1/1     Running   2 (4m57s ago)   7d7h
pod-demo    1/1     Running   0               14s
test        1/1     Running   4 (4m56s ago)   13d
test1       1/1     Running   4 (4m57s ago)   13d
test2       1/1     Running   4 (4m57s ago)   13d
root@k8s-deploy:/yaml# 

  提示:此pod只是在k8s上运行起来,它没有控制器的监视,对应pod删除,故障都不会自动恢复;

  Job控制器,详细说明请参考https://www.cnblogs.com/qiuhom-1874/p/14157306.html;

  job控制器配置清单示例

apiVersion: batch/v1
kind: Job
metadata:
  name: job-demo
  namespace: default
  labels:
    app: job-demo
spec:
  template:
    metadata:
      name: job-demo
      labels:
        app: job-demo
    spec:    
      containers:
      - name: job-demo-container
        image: harbor.ik8s.cc/baseimages/centos7:2023
        command: ["/bin/sh"]
        args: ["-c", "echo data init job at `date +%Y-%m-%d_%H-%M-%S` >> /cache/data.log"]
        volumeMounts:
        - mountPath: /cache
          name: cache-volume
        - name: localtime
          mountPath: /etc/localtime
      volumes:
      - name: cache-volume
        hostPath:
          path: /tmp/jobdata
      - name: localtime
        hostPath:
          path: /usr/share/zoneinfo/Asia/Shanghai
      restartPolicy: Never

  提示:定义job资源必须定义restartPolicy;

  应用清单

root@k8s-deploy:/yaml# kubectl get pods 
NAME        READY   STATUS    RESTARTS      AGE
net-test1   1/1     Running   3 (48m ago)   7d10h
pod-demo    1/1     Running   1 (48m ago)   3h32m
test        1/1     Running   5 (48m ago)   14d
test1       1/1     Running   5 (48m ago)   14d
test2       1/1     Running   5 (48m ago)   14d
root@k8s-deploy:/yaml# kubectl apply -f job-demo.yaml 
job.batch/job-demo created
root@k8s-deploy:/yaml# kubectl get pods -o wide
NAME             READY   STATUS      RESTARTS      AGE     IP               NODE           NOMINATED NODE   READINESS GATES
job-demo-z8gmb   0/1     Completed   0             26s     10.200.211.130   192.168.0.34   <none>           <none>
net-test1        1/1     Running     3 (49m ago)   7d10h   10.200.211.191   192.168.0.34   <none>           <none>
pod-demo         1/1     Running     1 (49m ago)   3h32m   10.200.155.138   192.168.0.36   <none>           <none>
test             1/1     Running     5 (49m ago)   14d     10.200.209.6     192.168.0.35   <none>           <none>
test1            1/1     Running     5 (49m ago)   14d     10.200.209.8     192.168.0.35   <none>           <none>
test2            1/1     Running     5 (49m ago)   14d     10.200.211.177   192.168.0.34   <none>           <none>
root@k8s-deploy:/yaml# 

  验证:查看192.168.0.34的/tmp/jobdata目录下是否有job执行的任务数据?

root@k8s-deploy:/yaml# ssh 192.168.0.34 "ls /tmp/jobdata"
data.log
root@k8s-deploy:/yaml# ssh 192.168.0.34 "cat /tmp/jobdata/data.log"
data init job at 2023-05-06_23-31-32
root@k8s-deploy:/yaml# 

  提示:可以看到对应job所在宿主机的/tmp/jobdata/目录下有job执行过后的数据,这说明我们定义的job任务顺利完成;

  定义并行job

apiVersion: batch/v1
kind: Job
metadata:
  name: job-multi-demo
  namespace: default
  labels:
    app: job-multi-demo
spec:
  completions: 5   
  template:
    metadata:
      name: job-multi-demo
      labels:
        app: job-multi-demo
    spec: 
      containers:
      - name: job-multi-demo-container
        image: harbor.ik8s.cc/baseimages/centos7:2023
        command: ["/bin/sh"]
        args: ["-c", "echo data init job at `date +%Y-%m-%d_%H-%M-%S` >> /cache/data.log"]
        volumeMounts:
        - mountPath: /cache
          name: cache-volume
        - name: localtime
          mountPath: /etc/localtime
      volumes:
      - name: cache-volume
        hostPath:
          path: /tmp/jobdata
      - name: localtime
        hostPath:
          path: /usr/share/zoneinfo/Asia/Shanghai
      restartPolicy: Never

  提示:spec字段下使用completions来指定执行任务需要的对应pod的数量;

  应用清单

root@k8s-deploy:/yaml# kubectl get pods 
NAME             READY   STATUS      RESTARTS      AGE
job-demo-z8gmb   0/1     Completed   0             24m
net-test1        1/1     Running     3 (73m ago)   7d11h
pod-demo         1/1     Running     1 (73m ago)   3h56m
test             1/1     Running     5 (73m ago)   14d
test1            1/1     Running     5 (73m ago)   14d
test2            1/1     Running     5 (73m ago)   14d
root@k8s-deploy:/yaml# kubectl apply -f job-multi-demo.yaml 
job.batch/job-multi-demo created
root@k8s-deploy:/yaml# kubectl get job
NAME             COMPLETIONS   DURATION   AGE
job-demo         1/1           5s         24m
job-multi-demo   1/5           10s        10s
root@k8s-deploy:/yaml# kubectl get pods -o wide
NAME                   READY   STATUS              RESTARTS      AGE     IP               NODE           NOMINATED NODE   READINESS GATES
job-demo-z8gmb         0/1     Completed           0             24m     10.200.211.130   192.168.0.34   <none>           <none>
job-multi-demo-5vp9w   0/1     Completed           0             12s     10.200.211.144   192.168.0.34   <none>           <none>
job-multi-demo-frstg   0/1     Completed           0             22s     10.200.211.186   192.168.0.34   <none>           <none>
job-multi-demo-gd44s   0/1     Completed           0             17s     10.200.211.184   192.168.0.34   <none>           <none>
job-multi-demo-kfm79   0/1     ContainerCreating   0             2s      <none>           192.168.0.34   <none>           <none>
job-multi-demo-nsmpg   0/1     Completed           0             7s      10.200.211.135   192.168.0.34   <none>           <none>
net-test1              1/1     Running             3 (73m ago)   7d11h   10.200.211.191   192.168.0.34   <none>           <none>
pod-demo               1/1     Running             1 (73m ago)   3h56m   10.200.155.138   192.168.0.36   <none>           <none>
test                   1/1     Running             5 (73m ago)   14d     10.200.209.6     192.168.0.35   <none>           <none>
test1                  1/1     Running             5 (73m ago)   14d     10.200.209.8     192.168.0.35   <none>           <none>
test2                  1/1     Running             5 (73m ago)   14d     10.200.211.177   192.168.0.34   <none>           <none>
root@k8s-deploy:/yaml# kubectl get pods -o wide
NAME                   READY   STATUS      RESTARTS      AGE     IP               NODE           NOMINATED NODE   READINESS GATES
job-demo-z8gmb         0/1     Completed   0             24m     10.200.211.130   192.168.0.34   <none>           <none>
job-multi-demo-5vp9w   0/1     Completed   0             33s     10.200.211.144   192.168.0.34   <none>           <none>
job-multi-demo-frstg   0/1     Completed   0             43s     10.200.211.186   192.168.0.34   <none>           <none>
job-multi-demo-gd44s   0/1     Completed   0             38s     10.200.211.184   192.168.0.34   <none>           <none>
job-multi-demo-kfm79   0/1     Completed   0             23s     10.200.211.140   192.168.0.34   <none>           <none>
job-multi-demo-nsmpg   0/1     Completed   0             28s     10.200.211.135   192.168.0.34   <none>           <none>
net-test1              1/1     Running     3 (73m ago)   7d11h   10.200.211.191   192.168.0.34   <none>           <none>
pod-demo               1/1     Running     1 (73m ago)   3h57m   10.200.155.138   192.168.0.36   <none>           <none>
test                   1/1     Running     5 (73m ago)   14d     10.200.209.6     192.168.0.35   <none>           <none>
test1                  1/1     Running     5 (73m ago)   14d     10.200.209.8     192.168.0.35   <none>           <none>
test2                  1/1     Running     5 (73m ago)   14d     10.200.211.177   192.168.0.34   <none>           <none>
root@k8s-deploy:/yaml# 

  验证:查看192.168.0.34的/tmp/jobdata/目录下是否有job数据产生?

root@k8s-deploy:/yaml# ssh 192.168.0.34 "ls /tmp/jobdata" 
data.log
root@k8s-deploy:/yaml# ssh 192.168.0.34 "cat /tmp/jobdata/data.log"
data init job at 2023-05-06_23-31-32
data init job at 2023-05-06_23-55-44
data init job at 2023-05-06_23-55-49
data init job at 2023-05-06_23-55-54
data init job at 2023-05-06_23-55-59
data init job at 2023-05-06_23-56-04
root@k8s-deploy:/yaml# 

  定义并行度

apiVersion: batch/v1
kind: Job
metadata:
  name: job-multi-demo2
  namespace: default
  labels:
    app: job-multi-demo2
spec:
  completions: 6
  parallelism: 2   
  template:
    metadata:
      name: job-multi-demo2
      labels:
        app: job-multi-demo2
    spec: 
      containers:
      - name: job-multi-demo2-container
        image: harbor.ik8s.cc/baseimages/centos7:2023
        command: ["/bin/sh"]
        args: ["-c", "echo data init job at `date +%Y-%m-%d_%H-%M-%S` >> /cache/data.log"]
        volumeMounts:
        - mountPath: /cache
          name: cache-volume
        - name: localtime
          mountPath: /etc/localtime
      volumes:
      - name: cache-volume
        hostPath:
          path: /tmp/jobdata
      - name: localtime
        hostPath:
          path: /usr/share/zoneinfo/Asia/Shanghai
      restartPolicy: Never

  提示:在spec字段下使用parallelism字段来指定并行度,即一次几个pod同时运行;上述清单表示,一次2个pod同时运行,总共需要6个pod;

  应用清单

root@k8s-deploy:/yaml# kubectl get jobs
NAME             COMPLETIONS   DURATION   AGE
job-demo         1/1           5s         34m
job-multi-demo   5/5           25s        9m56s
root@k8s-deploy:/yaml# kubectl apply -f job-multi-demo2.yaml 
job.batch/job-multi-demo2 created
root@k8s-deploy:/yaml# kubectl get jobs
NAME              COMPLETIONS   DURATION   AGE
job-demo          1/1           5s         34m
job-multi-demo    5/5           25s        10m
job-multi-demo2   0/6           2s         3s
root@k8s-deploy:/yaml# kubectl get pods 
NAME                    READY   STATUS      RESTARTS      AGE
job-demo-z8gmb          0/1     Completed   0             34m
job-multi-demo-5vp9w    0/1     Completed   0             10m
job-multi-demo-frstg    0/1     Completed   0             10m
job-multi-demo-gd44s    0/1     Completed   0             10m
job-multi-demo-kfm79    0/1     Completed   0             9m59s
job-multi-demo-nsmpg    0/1     Completed   0             10m
job-multi-demo2-7ppxc   0/1     Completed   0             10s
job-multi-demo2-mxbtq   0/1     Completed   0             5s
job-multi-demo2-rhgh7   0/1     Completed   0             4s
job-multi-demo2-th6ff   0/1     Completed   0             11s
net-test1               1/1     Running     3 (83m ago)   7d11h
pod-demo                1/1     Running     1 (83m ago)   4h6m
test                    1/1     Running     5 (83m ago)   14d
test1                   1/1     Running     5 (83m ago)   14d
test2                   1/1     Running     5 (83m ago)   14d
root@k8s-deploy:/yaml# kubectl get pods 
NAME                    READY   STATUS      RESTARTS      AGE
job-demo-z8gmb          0/1     Completed   0             34m
job-multi-demo-5vp9w    0/1     Completed   0             10m
job-multi-demo-frstg    0/1     Completed   0             10m
job-multi-demo-gd44s    0/1     Completed   0             10m
job-multi-demo-kfm79    0/1     Completed   0             10m
job-multi-demo-nsmpg    0/1     Completed   0             10m
job-multi-demo2-7ppxc   0/1     Completed   0             16s
job-multi-demo2-8bh22   0/1     Completed   0             6s
job-multi-demo2-dbjqw   0/1     Completed   0             6s
job-multi-demo2-mxbtq   0/1     Completed   0             11s
job-multi-demo2-rhgh7   0/1     Completed   0             10s
job-multi-demo2-th6ff   0/1     Completed   0             17s
net-test1               1/1     Running     3 (83m ago)   7d11h
pod-demo                1/1     Running     1 (83m ago)   4h6m
test                    1/1     Running     5 (83m ago)   14d
test1                   1/1     Running     5 (83m ago)   14d
test2                   1/1     Running     5 (83m ago)   14d
root@k8s-deploy:/yaml# kubectl get pods -o wide
NAME                    READY   STATUS      RESTARTS      AGE     IP               NODE           NOMINATED NODE   READINESS GATES
job-demo-z8gmb          0/1     Completed   0             35m     10.200.211.130   192.168.0.34   <none>           <none>
job-multi-demo-5vp9w    0/1     Completed   0             10m     10.200.211.144   192.168.0.34   <none>           <none>
job-multi-demo-frstg    0/1     Completed   0             11m     10.200.211.186   192.168.0.34   <none>           <none>
job-multi-demo-gd44s    0/1     Completed   0             11m     10.200.211.184   192.168.0.34   <none>           <none>
job-multi-demo-kfm79    0/1     Completed   0             10m     10.200.211.140   192.168.0.34   <none>           <none>
job-multi-demo-nsmpg    0/1     Completed   0             10m     10.200.211.135   192.168.0.34   <none>           <none>
job-multi-demo2-7ppxc   0/1     Completed   0             57s     10.200.211.145   192.168.0.34   <none>           <none>
job-multi-demo2-8bh22   0/1     Completed   0             47s     10.200.211.148   192.168.0.34   <none>           <none>
job-multi-demo2-dbjqw   0/1     Completed   0             47s     10.200.211.141   192.168.0.34   <none>           <none>
job-multi-demo2-mxbtq   0/1     Completed   0             52s     10.200.211.152   192.168.0.34   <none>           <none>
job-multi-demo2-rhgh7   0/1     Completed   0             51s     10.200.211.143   192.168.0.34   <none>           <none>
job-multi-demo2-th6ff   0/1     Completed   0             58s     10.200.211.136   192.168.0.34   <none>           <none>
net-test1               1/1     Running     3 (84m ago)   7d11h   10.200.211.191   192.168.0.34   <none>           <none>
pod-demo                1/1     Running     1 (84m ago)   4h7m    10.200.155.138   192.168.0.36   <none>           <none>
test                    1/1     Running     5 (84m ago)   14d     10.200.209.6     192.168.0.35   <none>           <none>
test1                   1/1     Running     5 (84m ago)   14d     10.200.209.8     192.168.0.35   <none>           <none>
test2                   1/1     Running     5 (84m ago)   14d     10.200.211.177   192.168.0.34   <none>           <none>
root@k8s-deploy:/yaml# 

  验证job数据

  提示:可以看到后面job追加的时间几乎都是两个重复的,这说明两个pod同时执行了job里的任务;

  Cronjob控制器,详细说明请参考https://www.cnblogs.com/qiuhom-1874/p/14157306.html;

  示例:定义cronjob

apiVersion: batch/v1
kind: CronJob
metadata:
  name: job-cronjob
  namespace: default
spec:
  schedule: "*/1 * * * *"
  jobTemplate:
    spec:
      parallelism: 2
      template:
        spec:
          containers:
          - name: job-cronjob-container
            image: harbor.ik8s.cc/baseimages/centos7:2023
            command: ["/bin/sh"]
            args: ["-c", "echo data init job at `date +%Y-%m-%d_%H-%M-%S` >> /cache/cronjob-data.log"]
            volumeMounts:
            - mountPath: /cache
              name: cache-volume
            - name: localtime
              mountPath: /etc/localtime
          volumes:
          - name: cache-volume
            hostPath:
              path: /tmp/jobdata
          - name: localtime
            hostPath:
              path: /usr/share/zoneinfo/Asia/Shanghai
          restartPolicy: OnFailure

  应用清单

root@k8s-deploy:/yaml# kubectl apply -f cronjob-demo.yaml
cronjob.batch/job-cronjob created
root@k8s-deploy:/yaml# kubectl get cronjob
NAME          SCHEDULE      SUSPEND   ACTIVE   LAST SCHEDULE   AGE
job-cronjob   */1 * * * *   False     0        <none>          6s
root@k8s-deploy:/yaml# kubectl get pods
NAME                         READY   STATUS      RESTARTS       AGE
job-cronjob-28056516-njddz   0/1     Completed   0              12s
job-cronjob-28056516-wgbns   0/1     Completed   0              12s
job-demo-z8gmb               0/1     Completed   0              64m
job-multi-demo-5vp9w         0/1     Completed   0              40m
job-multi-demo-frstg         0/1     Completed   0              40m
job-multi-demo-gd44s         0/1     Completed   0              40m
job-multi-demo-kfm79         0/1     Completed   0              40m
job-multi-demo-nsmpg         0/1     Completed   0              40m
job-multi-demo2-7ppxc        0/1     Completed   0              30m
job-multi-demo2-8bh22        0/1     Completed   0              30m
job-multi-demo2-dbjqw        0/1     Completed   0              30m
job-multi-demo2-mxbtq        0/1     Completed   0              30m
job-multi-demo2-rhgh7        0/1     Completed   0              30m
job-multi-demo2-th6ff        0/1     Completed   0              30m
net-test1                    1/1     Running     3 (113m ago)   7d11h
pod-demo                     1/1     Running     1 (113m ago)   4h36m
test                         1/1     Running     5 (113m ago)   14d
test1                        1/1     Running     5 (113m ago)   14d
test2                        1/1     Running     5 (113m ago)   14d
root@k8s-deploy:/yaml# kubectl get cronjob
NAME          SCHEDULE      SUSPEND   ACTIVE   LAST SCHEDULE   AGE
job-cronjob   */1 * * * *   False     0        12s             108s
root@k8s-deploy:/yaml# kubectl get pods   
NAME                         READY   STATUS      RESTARTS       AGE
job-cronjob-28056516-njddz   0/1     Completed   0              77s
job-cronjob-28056516-wgbns   0/1     Completed   0              77s
job-cronjob-28056517-d6n9h   0/1     Completed   0              17s
job-cronjob-28056517-krsvb   0/1     Completed   0              17s
job-demo-z8gmb               0/1     Completed   0              65m
job-multi-demo-5vp9w         0/1     Completed   0              41m
job-multi-demo-frstg         0/1     Completed   0              41m
job-multi-demo-gd44s         0/1     Completed   0              41m
job-multi-demo-kfm79         0/1     Completed   0              41m
job-multi-demo-nsmpg         0/1     Completed   0              41m
job-multi-demo2-7ppxc        0/1     Completed   0              31m
job-multi-demo2-8bh22        0/1     Completed   0              31m
job-multi-demo2-dbjqw        0/1     Completed   0              31m
job-multi-demo2-mxbtq        0/1     Completed   0              31m
job-multi-demo2-rhgh7        0/1     Completed   0              31m
job-multi-demo2-th6ff        0/1     Completed   0              31m
net-test1                    1/1     Running     3 (114m ago)   7d11h
pod-demo                     1/1     Running     1 (114m ago)   4h38m
test                         1/1     Running     5 (114m ago)   14d
test1                        1/1     Running     5 (114m ago)   14d
test2                        1/1     Running     5 (114m ago)   14d
root@k8s-deploy:/yaml# 

  提示:cronjob 默认保留最近3个历史记录;

  验证:查看周期执行任务的数据

   提示:从上面的时间就可以看到每过一分钟就有两个pod执行一次任务;

  RC/RS 副本控制器

  RC(Replication Controller),副本控制器,该控制器主要负责控制pod副本数量始终满足用户期望的副本数量,该副本控制器是第一代pod副本控制器,仅支持selector = !=;

  rc控制器示例

apiVersion: v1  
kind: ReplicationController  
metadata:  
  name: ng-rc
spec:  
  replicas: 2
  selector:  
    app: ng-rc-80 
  template:   
    metadata:  
      labels:  
        app: ng-rc-80
    spec:  
      containers:
      - name: pod-demo
        image: "harbor.ik8s.cc/baseimages/nginx:v1"
        ports:
        - containerPort:  80
          name:  http
        volumeMounts:
        - name: localtime
          mountPath: /etc/localtime
      volumes:
        - name: localtime
          hostPath:
            path: /usr/share/zoneinfo/Asia/Shanghai

  应用配置清单

root@k8s-deploy:/yaml# kubectl get pods 
NAME    READY   STATUS    RESTARTS      AGE
test    1/1     Running   6 (11m ago)   16d
test1   1/1     Running   6 (11m ago)   16d
test2   1/1     Running   6 (11m ago)   16d
root@k8s-deploy:/yaml# kubectl apply -f rc-demo.yaml
replicationcontroller/ng-rc created
root@k8s-deploy:/yaml# kubectl get pods -o wide
NAME          READY   STATUS    RESTARTS      AGE   IP               NODE           NOMINATED NODE   READINESS GATES
ng-rc-l7xmp   1/1     Running   0             10s   10.200.211.136   192.168.0.34   <none>           <none>
ng-rc-wl5d6   1/1     Running   0             9s    10.200.155.185   192.168.0.36   <none>           <none>
test          1/1     Running   6 (11m ago)   16d   10.200.209.24    192.168.0.35   <none>           <none>
test1         1/1     Running   6 (11m ago)   16d   10.200.209.31    192.168.0.35   <none>           <none>
test2         1/1     Running   6 (11m ago)   16d   10.200.211.186   192.168.0.34   <none>           <none>
root@k8s-deploy:/yaml# kubectl get rc
NAME    DESIRED   CURRENT   READY   AGE
ng-rc   2         2         2       25s
root@k8s-deploy:/yaml# 

  验证:修改pod标签,看看对应pod是否会重新创建?

root@k8s-deploy:/yaml# kubectl get pods --show-labels
NAME          READY   STATUS    RESTARTS      AGE     LABELS
ng-rc-l7xmp   1/1     Running   0             2m32s   app=ng-rc-80
ng-rc-wl5d6   1/1     Running   0             2m31s   app=ng-rc-80
test          1/1     Running   6 (13m ago)   16d     run=test
test1         1/1     Running   6 (13m ago)   16d     run=test1
test2         1/1     Running   6 (13m ago)   16d     run=test2
root@k8s-deploy:/yaml# kubectl label pod/ng-rc-l7xmp app=nginx-demo --overwrite
pod/ng-rc-l7xmp labeled
root@k8s-deploy:/yaml# kubectl get pods --show-labels                          
NAME          READY   STATUS              RESTARTS      AGE     LABELS
ng-rc-l7xmp   1/1     Running             0             4m42s   app=nginx-demo
ng-rc-rxvd4   0/1     ContainerCreating   0             3s      app=ng-rc-80
ng-rc-wl5d6   1/1     Running             0             4m41s   app=ng-rc-80
test          1/1     Running             6 (15m ago)   16d     run=test
test1         1/1     Running             6 (15m ago)   16d     run=test1
test2         1/1     Running             6 (15m ago)   16d     run=test2
root@k8s-deploy:/yaml# kubectl get pods --show-labels
NAME          READY   STATUS    RESTARTS      AGE     LABELS
ng-rc-l7xmp   1/1     Running   0             4m52s   app=nginx-demo
ng-rc-rxvd4   1/1     Running   0             13s     app=ng-rc-80
ng-rc-wl5d6   1/1     Running   0             4m51s   app=ng-rc-80
test          1/1     Running   6 (16m ago)   16d     run=test
test1         1/1     Running   6 (16m ago)   16d     run=test1
test2         1/1     Running   6 (16m ago)   16d     run=test2
root@k8s-deploy:/yaml# kubectl label pod/ng-rc-l7xmp app=ng-rc-80 --overwrite  
pod/ng-rc-l7xmp labeled
root@k8s-deploy:/yaml# kubectl get pods --show-labels                        
NAME          READY   STATUS    RESTARTS      AGE     LABELS
ng-rc-l7xmp   1/1     Running   0             5m27s   app=ng-rc-80
ng-rc-wl5d6   1/1     Running   0             5m26s   app=ng-rc-80
test          1/1     Running   6 (16m ago)   16d     run=test
test1         1/1     Running   6 (16m ago)   16d     run=test1
test2         1/1     Running   6 (16m ago)   16d     run=test2
root@k8s-deploy:/yaml# 

  提示:rc控制器是通过标签选择器来识别对应pod是否归属对应rc控制器管控,如果发现对应pod的标签发生改变,那么rc控制器会通过新建或删除的方法将对应pod数量始终和用户定义的数量保持一致;

  RS(ReplicaSet),副本控制器,该副本控制器和rc类似,都是通过标签选择器来匹配归属自己管控的pod数量,如果标签或对应pod数量少于或多余用户期望的数量,该控制器会通过新建或删除pod的方式将对应pod数量始终和用户期望的pod数量保持一致;rs控制器和rc控制器唯一区别就是rs控制器支持selector = !=精确匹配外,还支持模糊匹配in notin;是k8s之上的第二代pod副本控制器;

  rs控制器示例

apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: rs-demo
  labels:
    app: rs-demo
spec:
  replicas: 3
  selector:
    matchLabels:
      app: rs-demo
  template:
    metadata:
      labels:
        app: rs-demo
    spec:
      containers:
      - name: rs-demo
        image: "harbor.ik8s.cc/baseimages/nginx:v1"
        ports:
        - name: web
          containerPort:  80
          protocol: TCP
        env:
        - name: NGX_VERSION
          value: 1.16.1
        volumeMounts:
        - name: localtime
          mountPath: /etc/localtime
      volumes:
        - name: localtime
          hostPath:
            path: /usr/share/zoneinfo/Asia/Shanghai

  应用配置清单

  验证:修改pod标签,看看对应pod是否会发生变化?

root@k8s-deploy:/yaml# kubectl get pods --show-labels
NAME            READY   STATUS    RESTARTS      AGE   LABELS
ng-rc-l7xmp     1/1     Running   0             18m   app=ng-rc-80
ng-rc-wl5d6     1/1     Running   0             18m   app=ng-rc-80
rs-demo-nzmqs   1/1     Running   0             71s   app=rs-demo
rs-demo-v2vb6   1/1     Running   0             71s   app=rs-demo
rs-demo-x27fv   1/1     Running   0             71s   app=rs-demo
test            1/1     Running   6 (29m ago)   16d   run=test
test1           1/1     Running   6 (29m ago)   16d   run=test1
test2           1/1     Running   6 (29m ago)   16d   run=test2
root@k8s-deploy:/yaml# kubectl label pod/rs-demo-nzmqs app=nginx --overwrite 
pod/rs-demo-nzmqs labeled
root@k8s-deploy:/yaml# kubectl get pods --show-labels                       
NAME            READY   STATUS    RESTARTS      AGE    LABELS
ng-rc-l7xmp     1/1     Running   0             19m    app=ng-rc-80
ng-rc-wl5d6     1/1     Running   0             19m    app=ng-rc-80
rs-demo-bdfdd   1/1     Running   0             4s     app=rs-demo
rs-demo-nzmqs   1/1     Running   0             103s   app=nginx
rs-demo-v2vb6   1/1     Running   0             103s   app=rs-demo
rs-demo-x27fv   1/1     Running   0             103s   app=rs-demo
test            1/1     Running   6 (30m ago)   16d    run=test
test1           1/1     Running   6 (30m ago)   16d    run=test1
test2           1/1     Running   6 (30m ago)   16d    run=test2
root@k8s-deploy:/yaml# kubectl label pod/rs-demo-nzmqs app=rs-demo --overwrite
pod/rs-demo-nzmqs labeled
root@k8s-deploy:/yaml# kubectl get pods --show-labels                         
NAME            READY   STATUS    RESTARTS      AGE    LABELS
ng-rc-l7xmp     1/1     Running   0             19m    app=ng-rc-80
ng-rc-wl5d6     1/1     Running   0             19m    app=ng-rc-80
rs-demo-nzmqs   1/1     Running   0             119s   app=rs-demo
rs-demo-v2vb6   1/1     Running   0             119s   app=rs-demo
rs-demo-x27fv   1/1     Running   0             119s   app=rs-demo
test            1/1     Running   6 (30m ago)   16d    run=test
test1           1/1     Running   6 (30m ago)   16d    run=test1
test2           1/1     Running   6 (30m ago)   16d    run=test2
root@k8s-deploy:/yaml# 

  提示:可以看到当我们修改pod标签为其他标签以后,对应rs控制器会新建一个pod,其标签为app=rs-demo,这是因为当我们修改pod标签以后,rs控制器发现标签选择器匹配的pod数量少于用户定义的数量,所以rs控制器会新建一个标签为app=rs-demo的pod;当我们把pod标签修改为rs-demo时,rs控制器发现对应标签选择器匹配pod数量多余用户期望的pod数量,此时rs控制器会通过删除pod方法,让app=rs-demo标签的pod和用户期望的pod数量保持一致;

  Deployment 副本控制器,详细说明请参考https://www.cnblogs.com/qiuhom-1874/p/14149042.html;

  Deployment副本控制器时k8s第三代pod副本控制器,该控制器比rs控制器更高级,除了有rs的功能之外,还有很多高级功能,,比如说最重要的滚动升级、回滚等;

  deploy控制器示例

apiVersion: apps/v1
kind: Deployment
metadata:
  name:  deploy-demo
  namespace: default
  labels:
    app:  deploy-demo
spec:
  selector:
    matchLabels:
      app: deploy-demo
  replicas: 2
  template:
    metadata:
      labels:
        app:  deploy-demo
    spec:
      containers:
      - name:  deploy-demo
        image:  "harbor.ik8s.cc/baseimages/nginx:v1"
        ports:
        - containerPort:  80
          name:  http
        volumeMounts:
        - name: localtime
          mountPath: /etc/localtime
      volumes:
        - name: localtime
          hostPath:
            path: /usr/share/zoneinfo/Asia/Shanghai

  应用配置清单

  提示:deploy控制器是通过创建rs控制器来实现管控对应pod数量;

   通过修改镜像版本来更新pod版本

  应用配置清单

  使用命令更新pod版本

   查看rs更新历史版本

   查看更新历史记录

  提示:这里历史记录中没有记录版本信息,原因是默认不记录,需要记录历史版本,可以手动使用--record选项来记录版本信息;如下所示

  查看某个历史版本的详细信息

  提示:查看某个历史版本的详细信息,加上--revision=对应历史版本的编号即可;

  回滚到上一个版本

  提示:使用kubectl rollout undo 命令可以将对应deploy回滚到上一个版本;

  回滚指定编号的历史版本

  提示:使用--to-revision选项来指定对应历史版本编号,即可回滚到对应编号的历史版本;

  Service资源,详细说明请参考https://www.cnblogs.com/qiuhom-1874/p/14161950.html;

  nodeport类型的service访问流程

  nodeport类型service主要解决了k8s集群外部客户端访问pod,其流程是外部客户端访问k8s集群任意node节点的对应暴露的端口,被访问的node或通过本机的iptables或ipvs规则将外部客户端流量转发给对应pod之上,从而实现外部客户端访问k8s集群pod的目的;通常使用nodeport类型service为了方便外部客户端访问,都会在集群外部部署一个负载均衡器,即外部客户端访问对应负载均衡器的对应端口,通过负载均衡器将外部客户端流量引入k8s集群,从而完成对pod的访问;

  ClusterIP类型svc示例

apiVersion: v1
kind: Service
metadata:
  name: ngx-svc
  namespace: default
spec:
  selector:
    app: deploy-demo
  type: ClusterIP
  ports:
  - name: http
    protocol: TCP
    port: 80
    targetPort: 80

  应用配置清单

  提示:可以看到创建clusterip类型service以后,对应svc会有一个clusterip,后端endpoints会通过标签选择器去关联对应pod,即我们访问对应svc的clusterip,对应流量会被转发至后端endpoint pod之上进行响应;不过这种clusterip类型svc只能在k8s集群内部客户端访问,集群外部客户端是访问不到的,原因是这个clusterip是k8s内部网络IP地址;

  验证,访问10.100.100.23的80端口,看看对应后端nginxpod是否可以正常被访问呢?

root@k8s-node01:~# curl 10.100.100.23
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>
root@k8s-node01:~# 

  nodeport类型service示例

apiVersion: v1
kind: Service
metadata:
  name: ngx-nodeport-svc
  namespace: default
spec:
  selector:
    app: deploy-demo
  type: NodePort
  ports:
  - name: http
    protocol: TCP
    port: 80
    targetPort: 80
    nodePort: 30012

  提示:nodeport类型service只需要在clusterip类型的svc之上修改type为NodePort,然后再ports字段下用nodePort指定对应node端口即可;

  应用配置清单

root@k8s-deploy:/yaml# kubectl apply -f nodeport-svc-demo.yaml
service/ngx-nodeport-svc created
root@k8s-deploy:/yaml# kubectl get svc
NAME               TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
kubernetes         ClusterIP   10.100.0.1       <none>        443/TCP        16d
ngx-nodeport-svc   NodePort    10.100.209.225   <none>        80:30012/TCP   11s
root@k8s-deploy:/yaml# kubectl describe svc ngx-nodeport-svc
Name:                     ngx-nodeport-svc
Namespace:                default
Labels:                   <none>
Annotations:              <none>
Selector:                 app=deploy-demo
Type:                     NodePort
IP Family Policy:         SingleStack
IP Families:              IPv4
IP:                       10.100.209.225
IPs:                      10.100.209.225
Port:                     http  80/TCP
TargetPort:               80/TCP
NodePort:                 http  30012/TCP
Endpoints:                10.200.155.178:80,10.200.211.138:80
Session Affinity:         None
External Traffic Policy:  Cluster
Events:                   <none>
root@k8s-deploy:/yaml# 

  验证:访问k8s集群任意node的30012端口,看看对应nginxpod是否能够被访问到?

root@k8s-deploy:/yaml# curl 192.168.0.34:30012  
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>
root@k8s-deploy:/yaml# 

  提示:可以看到k8s外部客户端访问k8snode节点的30012端口是能够正常访问到nginxpod;当然集群内部的客户端是可以通过对应生成的clusterip进行访问的;

root@k8s-node01:~# curl 10.100.209.225:30012
curl: (7) Failed to connect to 10.100.209.225 port 30012 after 0 ms: Connection refused
root@k8s-node01:~# curl 127.0.0.1:30012     
curl: (7) Failed to connect to 127.0.0.1 port 30012 after 0 ms: Connection refused
root@k8s-node01:~# curl 192.168.0.34:30012
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="http://nginx.org/">nginx.org</a>.<br/>
Commercial support is available at
<a href="http://nginx.com/">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>
root@k8s-node01:~# 

  提示:集群内部客户端只能访问clusterip的80端口,或者访问node的对外IP的30012端口;

  Volume资源,详细说明请参考https://www.cnblogs.com/qiuhom-1874/p/14180752.html;

  pod挂载nfs的使用

  在nfs服务器上准备数据目录

root@harbor:~# cat /etc/exports
# /etc/exports: the access control list for filesystems which may be exported
#               to NFS clients.  See exports(5).
#
# Example for NFSv2 and NFSv3:
# /srv/homes       hostname1(rw,sync,no_subtree_check) hostname2(ro,sync,no_subtree_check)
#
# Example for NFSv4:
# /srv/nfs4        gss/krb5i(rw,sync,fsid=0,crossmnt,no_subtree_check)
# /srv/nfs4/homes  gss/krb5i(rw,sync,no_subtree_check)
#
/data/k8sdata/kuboard *(rw,no_root_squash)
/data/volumes *(rw,no_root_squash)
/pod-vol *(rw,no_root_squash)
root@harbor:~# mkdir -p /pod-vol
root@harbor:~# ls /pod-vol -d
/pod-vol
root@harbor:~# exportfs -av
exportfs: /etc/exports [1]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/kuboard".
  Assuming default behaviour ('no_subtree_check').
  NOTE: this default has changed since nfs-utils version 1.0.x

exportfs: /etc/exports [2]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/volumes".
  Assuming default behaviour ('no_subtree_check').
  NOTE: this default has changed since nfs-utils version 1.0.x

exportfs: /etc/exports [3]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/pod-vol".
  Assuming default behaviour ('no_subtree_check').
  NOTE: this default has changed since nfs-utils version 1.0.x

exporting *:/pod-vol
exporting *:/data/volumes
exporting *:/data/k8sdata/kuboard
root@harbor:~# 

  在pod上挂载nfs目录

apiVersion: apps/v1
kind: Deployment
metadata:
  name:  ngx-nfs-80
  namespace: default
  labels:
    app:  ngx-nfs-80
spec:
  selector:
    matchLabels:
      app: ngx-nfs-80
  replicas: 1
  template:
    metadata:
      labels:
        app:  ngx-nfs-80
    spec:
      containers:
      - name:  ngx-nfs-80
        image:  "harbor.ik8s.cc/baseimages/nginx:v1"
        resources:
          requests:
            cpu: 100m
            memory: 100Mi
          limits:
            cpu: 100m
            memory: 100Mi
        ports:
        - containerPort:  80
          name:  ngx-nfs-80
        volumeMounts:
        - name: localtime
          mountPath: /etc/localtime
        - name: nfs-vol
          mountPath: /usr/share/nginx/html/
      volumes:
        - name: localtime
          hostPath:
            path: /usr/share/zoneinfo/Asia/Shanghai
        - name: nfs-vol
          nfs:
            server: 192.168.0.42
            path: /pod-vol
      restartPolicy: Always
---
apiVersion: v1
kind: Service
metadata:
  name: ngx-nfs-svc
  namespace: default
spec:
  selector:
    app: ngx-nfs-80
  type: NodePort
  ports:
  - name: ngx-nfs-svc
    protocol: TCP
    port: 80
    targetPort: 80
    nodePort: 30013

  应用配置清单

root@k8s-deploy:/yaml# kubectl apply -f nfs-vol.yaml 
deployment.apps/ngx-nfs-80 created
service/ngx-nfs-svc created
root@k8s-deploy:/yaml# kubectl get pods 
NAME                           READY   STATUS    RESTARTS      AGE
deploy-demo-6849bdf444-pvsc9   1/1     Running   1 (57m ago)   46h
deploy-demo-6849bdf444-sg8fz   1/1     Running   1 (57m ago)   46h
ng-rc-l7xmp                    1/1     Running   1 (57m ago)   47h
ng-rc-wl5d6                    1/1     Running   1 (57m ago)   47h
ngx-nfs-80-66c9697cf4-8pm9k    1/1     Running   0             7s
rs-demo-nzmqs                  1/1     Running   1 (57m ago)   47h
rs-demo-v2vb6                  1/1     Running   1 (57m ago)   47h
rs-demo-x27fv                  1/1     Running   1 (57m ago)   47h
test                           1/1     Running   7 (57m ago)   17d
test1                          1/1     Running   7 (57m ago)   17d
test2                          1/1     Running   7 (57m ago)   17d
root@k8s-deploy:/yaml# kubectl get svc
NAME               TYPE        CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
kubernetes         ClusterIP   10.100.0.1       <none>        443/TCP        18d
ngx-nfs-svc        NodePort    10.100.16.14     <none>        80:30013/TCP   15s
ngx-nodeport-svc   NodePort    10.100.209.225   <none>        80:30012/TCP   45h
root@k8s-deploy:/yaml# 

  在nfs服务器上/pod-vol目录下提供index.html文件

root@harbor:~# echo "this page from nfs server.." >> /pod-vol/index.html
root@harbor:~# cat /pod-vol/index.html
this page from nfs server..
root@harbor:~# 

  访问pod,看看nfs服务器上的inde.html是否能够正常访问到?

root@k8s-deploy:/yaml# curl 192.168.0.35:30013
this page from nfs server..
root@k8s-deploy:/yaml# 

  提示:能够看到访问pod对应返回的页面就是刚才在nfs服务器上创建的页面,说明pod正常挂载了nfs提供的目录;

  PV、PVC资源,详细说明请参考https://www.cnblogs.com/qiuhom-1874/p/14188621.html;

  nfs实现静态pvc的使用

  在nfs服务器上准备目录

root@harbor:~# cat /etc/exports 
# /etc/exports: the access control list for filesystems which may be exported
#               to NFS clients.  See exports(5).
#
# Example for NFSv2 and NFSv3:
# /srv/homes       hostname1(rw,sync,no_subtree_check) hostname2(ro,sync,no_subtree_check)
#
# Example for NFSv4:
# /srv/nfs4        gss/krb5i(rw,sync,fsid=0,crossmnt,no_subtree_check)
# /srv/nfs4/homes  gss/krb5i(rw,sync,no_subtree_check)
#
/data/k8sdata/kuboard *(rw,no_root_squash)
/data/volumes *(rw,no_root_squash)
/pod-vol *(rw,no_root_squash)
/data/k8sdata/myserver/myappdata *(rw,no_root_squash)
root@harbor:~# mkdir -p /data/k8sdata/myserver/myappdata
root@harbor:~# exportfs -av
exportfs: /etc/exports [1]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/kuboard".
  Assuming default behaviour ('no_subtree_check').
  NOTE: this default has changed since nfs-utils version 1.0.x

exportfs: /etc/exports [2]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/volumes".
  Assuming default behaviour ('no_subtree_check').
  NOTE: this default has changed since nfs-utils version 1.0.x

exportfs: /etc/exports [3]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/pod-vol".
  Assuming default behaviour ('no_subtree_check').
  NOTE: this default has changed since nfs-utils version 1.0.x

exportfs: /etc/exports [4]: Neither 'subtree_check' or 'no_subtree_check' specified for export "*:/data/k8sdata/myserver/myappdata".
  Assuming default behaviour ('no_subtree_check').
  NOTE: this default has changed since nfs-utils version 1.0.x

exporting *:/data/k8sdata/myserver/myappdata
exporting *:/pod-vol
exporting *:/data/volumes
exporting *:/data/k8sdata/kuboard
root@harbor:~# 

  创建pv

apiVersion: v1
kind: PersistentVolume
metadata:
  name: myapp-static-pv
  namespace: default
spec:
  capacity:
    storage: 2Gi
  accessModes:
    - ReadWriteOnce
  nfs:
    path: /data/k8sdata/myserver/myappdata
    server: 192.168.0.42

  创建pvc关联pv

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: myapp-static-pvc
  namespace: default
spec:
  volumeName: myapp-static-pv
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 2Gi

  创建pod使用pvc

apiVersion: apps/v1
kind: Deployment
metadata:
  name:  ngx-nfs-pvc-80
  namespace: default
  labels:
    app:  ngx-pvc-80
spec:
  selector:
    matchLabels:
      app: ngx-pvc-80
  replicas: 1
  template:
    metadata:
      labels:
        app:  ngx-pvc-80
    spec:
      containers:
      - name:  ngx-pvc-80
        image:  "harbor.ik8s.cc/baseimages/nginx:v1"
        resources:
          requests:
            cpu: 100m
            memory: 100Mi
          limits:
            cpu: 100m
            memory: 100Mi
        ports:
        - containerPort:  80
          name:  ngx-pvc-80
        volumeMounts:
        - name: localtime
          mountPath: /etc/localtime
        - name: data-pvc
          mountPath: /usr/share/nginx/html/
      volumes:
        - name: localtime
          hostPath:
            path: /usr/share/zoneinfo/Asia/Shanghai
        - name: data-pvc
          persistentVolumeClaim:
            claimName: myapp-static-pvc 

---
apiVersion: v1
kind: Service
metadata:
  name: ngx-pvc-svc
  namespace: default
spec:
  selector:
    app: ngx-pvc-80
  type: NodePort
  ports:
  - name: ngx-nfs-svc
    protocol: TCP
    port: 80
    targetPort: 80
    nodePort: 30014

  应用上述配置清单

root@k8s-deploy:/yaml# kubectl apply -f nfs-static-pvc-demo.yaml 
persistentvolume/myapp-static-pv created
persistentvolumeclaim/myapp-static-pvc created
deployment.apps/ngx-nfs-pvc-80 created
service/ngx-pvc-svc created
root@k8s-deploy:/yaml# kubectl get pv
NAME              CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                      STORAGECLASS   REASON   AGE
myapp-static-pv   2Gi        RWO            Retain           Bound    default/myapp-static-pvc                           4s
root@k8s-deploy:/yaml# kubectl get pvc
NAME               STATUS    VOLUME            CAPACITY   ACCESS MODES   STORAGECLASS   AGE
myapp-static-pvc   Pending   myapp-static-pv   0                                        7s
root@k8s-deploy:/yaml# kubectl get pods 
NAME                            READY   STATUS    RESTARTS       AGE
deploy-demo-6849bdf444-pvsc9    1/1     Running   1 (151m ago)   47h
deploy-demo-6849bdf444-sg8fz    1/1     Running   1 (151m ago)   47h
ng-rc-l7xmp                     1/1     Running   1 (151m ago)   2d1h
ng-rc-wl5d6                     1/1     Running   1 (151m ago)   2d1h
ngx-nfs-pvc-80-f776bb6d-nwwwq   0/1     Pending   0              10s
rs-demo-nzmqs                   1/1     Running   1 (151m ago)   2d
rs-demo-v2vb6                   1/1     Running   1 (151m ago)   2d
rs-demo-x27fv                   1/1     Running   1 (151m ago)   2d
test                            1/1     Running   7 (151m ago)   18d
test1                           1/1     Running   7 (151m ago)   18d
test2                           1/1     Running   7 (151m ago)   18d
root@k8s-deploy:/yaml# 

  在nfs服务器上/data/k8sdata/myserver/myappdata创建index.html,看看对应主页是否能够被访问?

root@harbor:~# echo "this page from nfs-server /data/k8sdata/myserver/myappdata/index.html" >> /data/k8sdata/myserver/myappdata/index.html
root@harbor:~# cat /data/k8sdata/myserver/myappdata/index.html
this page from nfs-server /data/k8sdata/myserver/myappdata/index.html
root@harbor:~# 

  访问pod

root@harbor:~# curl 192.168.0.36:30014
this page from nfs-server /data/k8sdata/myserver/myappdata/index.html
root@harbor:~# 

  nfs实现动态pvc的使用

   创建名称空间、服务账号、clusterrole、clusterrolebindding、role、rolebinding

apiVersion: v1
kind: Namespace
metadata:
  name: nfs
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: nfs
---
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: nfs
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: nfs
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: nfs
subjects:
  - kind: ServiceAccount
    name: nfs-client-provisioner
    # replace with namespace where provisioner is deployed
    namespace: nfs
roleRef:
  kind: Role
  name: leader-locking-nfs-client-provisioner
  apiGroup: rbac.authorization.k8s.io

  创建sc

apiVersion: storage.k8s.io/v1
kind: StorageClass
metadata:
  name: managed-nfs-storage
provisioner: k8s-sigs.io/nfs-subdir-external-provisioner # or choose another name, must match deployment's env PROVISIONER_NAME'
reclaimPolicy: Retain #PV的删除策略,默认为delete,删除PV后立即删除NFS server的数据
mountOptions:
  #- vers=4.1 #containerd有部分参数异常
  #- noresvport #告知NFS客户端在重新建立网络连接时,使用新的传输控制协议源端口
  - noatime #访问文件时不更新文件inode中的时间戳,高并发环境可提高性能
parameters:
  #mountOptions: "vers=4.1,noresvport,noatime"
  archiveOnDelete: "true"  #删除pod时保留pod数据,默认为false时为不保留数据 

  创建provision

apiVersion: apps/v1
kind: Deployment
metadata:
  name: nfs-client-provisioner
  labels:
    app: nfs-client-provisioner
  # replace with namespace where provisioner is deployed
  namespace: nfs
spec:
  replicas: 1
  strategy: #部署策略
    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: k8s.gcr.io/sig-storage/nfs-subdir-external-provisioner:v4.0.2 
          image: registry.cn-qingdao.aliyuncs.com/zhangshijie/nfs-subdir-external-provisioner:v4.0.2 
          volumeMounts:
            - name: nfs-client-root
              mountPath: /persistentvolumes
          env:
            - name: PROVISIONER_NAME
              value: k8s-sigs.io/nfs-subdir-external-provisioner
            - name: NFS_SERVER
              value: 192.168.0.42
            - name: NFS_PATH
              value: /data/volumes
      volumes:
        - name: nfs-client-root
          nfs:
            server: 192.168.0.42
            path: /data/volumes

  调用sc创建pvc

apiVersion: v1
kind: Namespace
metadata:
  name: myserver
---   
# Test PVC
kind: PersistentVolumeClaim
apiVersion: v1
metadata:
  name: myserver-myapp-dynamic-pvc
  namespace: myserver
spec:
  storageClassName: managed-nfs-storage #调用的storageclass 名称
  accessModes:
    - ReadWriteMany #访问权限
  resources:
    requests:
      storage: 500Mi #空间大小

  创建app使用pvc

kind: Deployment
#apiVersion: extensions/v1beta1
apiVersion: apps/v1
metadata:
  labels:
    app: myserver-myapp 
  name: myserver-myapp-deployment-name
  namespace: myserver
spec:
  replicas: 1 
  selector:
    matchLabels:
      app: myserver-myapp-frontend
  template:
    metadata:
      labels:
        app: myserver-myapp-frontend
    spec:
      containers:
        - name: myserver-myapp-container
          image: nginx:1.20.0 
          #imagePullPolicy: Always
          volumeMounts:
          - mountPath: "/usr/share/nginx/html/statics"
            name: statics-datadir
      volumes:
        - name: statics-datadir
          persistentVolumeClaim:
            claimName: myserver-myapp-dynamic-pvc 

---
kind: Service
apiVersion: v1
metadata:
  labels:
    app: myserver-myapp-service
  name: myserver-myapp-service-name
  namespace: myserver
spec:
  type: NodePort
  ports:
  - name: http
    port: 80
    targetPort: 80
    nodePort: 30015
  selector:
    app: myserver-myapp-frontend

  应用上述配置清单

root@k8s-deploy:/yaml/myapp# kubectl apply -f .
namespace/nfs created
serviceaccount/nfs-client-provisioner created
clusterrole.rbac.authorization.k8s.io/nfs-client-provisioner-runner created
clusterrolebinding.rbac.authorization.k8s.io/run-nfs-client-provisioner created
role.rbac.authorization.k8s.io/leader-locking-nfs-client-provisioner created
rolebinding.rbac.authorization.k8s.io/leader-locking-nfs-client-provisioner created
storageclass.storage.k8s.io/managed-nfs-storage created
deployment.apps/nfs-client-provisioner created
namespace/myserver created
persistentvolumeclaim/myserver-myapp-dynamic-pvc created
deployment.apps/myserver-myapp-deployment-name created
service/myserver-myapp-service-name created
root@k8s-deploy:

  验证:查看sc、pv、pvc是否创建?pod是否正常运行?

root@k8s-deploy:/yaml/myapp# kubectl get sc
NAME                  PROVISIONER                                   RECLAIMPOLICY   VOLUMEBINDINGMODE   ALLOWVOLUMEEXPANSION   AGE
managed-nfs-storage   k8s-sigs.io/nfs-subdir-external-provisioner   Retain          Immediate           false                  105s
root@k8s-deploy:/yaml/myapp# kubectl get pv
NAME                                       CAPACITY   ACCESS MODES   RECLAIM POLICY   STATUS   CLAIM                                 STORAGECLASS          REASON   AGE
pvc-01709c7f-0cf9-4554-9ae9-72db89e7308c   500Mi      RWX            Retain           Bound    myserver/myserver-myapp-dynamic-pvc   managed-nfs-storage            107s
root@k8s-deploy:/yaml/myapp# kubectl get pvc -n myserver
NAME                         STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS          AGE
myserver-myapp-dynamic-pvc   Bound    pvc-01709c7f-0cf9-4554-9ae9-72db89e7308c   500Mi      RWX            managed-nfs-storage   117s
root@k8s-deploy:/yaml/myapp# kubectl get pods -n myserver
NAME                                              READY   STATUS    RESTARTS   AGE
myserver-myapp-deployment-name-65ff65446f-xpd5p   1/1     Running   0          2m8s
root@k8s-deploy:/yaml/myapp# 

  提示:可以看到pv自动由sc创建,pvc自动和pv关联;

  验证:在nfs服务器上的/data/volumes/下创建index.html文件,访问pod service,看看对应文件是否能够正常被访问到?

root@harbor:/data/volumes# ls
myserver-myserver-myapp-dynamic-pvc-pvc-01709c7f-0cf9-4554-9ae9-72db89e7308c
root@harbor:/data/volumes# cd myserver-myserver-myapp-dynamic-pvc-pvc-01709c7f-0cf9-4554-9ae9-72db89e7308c/
root@harbor:/data/volumes/myserver-myserver-myapp-dynamic-pvc-pvc-01709c7f-0cf9-4554-9ae9-72db89e7308c# ls
root@harbor:/data/volumes/myserver-myserver-myapp-dynamic-pvc-pvc-01709c7f-0cf9-4554-9ae9-72db89e7308c# echo "this page from nfs-server /data/volumes" >> index.html
root@harbor:/data/volumes/myserver-myserver-myapp-dynamic-pvc-pvc-01709c7f-0cf9-4554-9ae9-72db89e7308c# cat index.html 
this page from nfs-server /data/volumes
root@harbor:/data/volumes/myserver-myserver-myapp-dynamic-pvc-pvc-01709c7f-0cf9-4554-9ae9-72db89e7308c# 

  提示:在nfs服务器上的/data/volumes目录下会自动生成一个使用pvcpod所在名称空间+pvc名字+pv名字的一个目录,这个目录就是由provision创建;

  访问pod

root@harbor:~# curl 192.168.0.36:30015/statics/index.html
this page from nfs-server /data/volumes
root@harbor:~# 

  提示:能够访问到我们刚才创建的文件,说明pod正常挂载nfs服务器对应目录;

  PV/PVC总结

  PV是对底层网络存储的抽象,即将网络存储定义为一种存储资源,将一个整体的存储资源拆分成多份后给不同的业务使用。

  PVC是对PV资源的申请调用,pod是通过PVC将数据保存至PV,PV再把数据保存至真正的硬件存储。

  PersistentVolume参数

  Capacity: #当前PV空间大小,kubectl explain PersistentVolume.spec.capacity

  accessModes :访问模式,#kubectl explain PersistentVolume.spec.accessModes

    ReadWriteOnce – PV只能被单个节点以读写权限挂载,RWO

    ReadOnlyMany – PV以可以被多个节点挂载但是权限是只读的,ROX
    ReadWriteMany – PV可以被多个节点是读写方式挂载使用,RWX

  persistentVolumeReclaimPolicy #删除机制即删除存储卷卷时候,已经创建好的存储卷由以下删除操作:

    Retain – 删除PV后保持原装,最后需要管理员手动删除

    Recycle – 空间回收,及删除存储卷上的所有数据(包括目录和隐藏文件),目前仅支持NFS和hostPath

    Delete – 自动删除存储卷

  volumeMode #卷类型,kubectl explain PersistentVolume.spec.volumeMode;定义存储卷使用的文件系统是块设备还是文件系统,默认为文件系统

  mountOptions #附加的挂载选项列表,实现更精细的权限控制;

  官方文档:持久卷 | Kubernetes;

  PersistentVolumeClaim创建参数

  accessModes :PVC 访问模式,#kubectl explain PersistentVolumeClaim.spec.volumeMode

    ReadWriteOnce – PVC只能被单个节点以读写权限挂载,RWO

    ReadOnlyMany – PVC以可以被多个节点挂载但是权限是只读的,ROX

    ReadWriteMany – PVC可以被多个节点是读写方式挂载使用,RWX

  resources: #定义PVC创建存储卷的空间大小

  selector: #标签选择器,选择要绑定的PV

    matchLabels #匹配标签名称

    matchExpressions #基于正则表达式匹配

  volumeName #要绑定的PV名称

  volumeMode #卷类型,定义PVC使用的文件系统是块设备还是文件系统,默认为文件系统

  Volume- 存储卷类型

  static:静态存储卷 ,需要在使用前手动创建PV、然后创建PVC并绑定到PV然后挂载至pod使用,适用于PV和PVC相对比较固定的业务场景。

  dynamin:动态存储卷,先创建一个存储类storageclass,后期pod在使用PVC的时候可以通过存储类动态创建PVC,适用于有状态服务集群如MySQL一主多从、zookeeper集群等。

  存储类官方文档:存储类 | Kubernetes

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