V2AS问路
k8s资源对象
阅读原文时间：2023年07月10日阅读：3

　　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
net-test1 1/1 Running 3 (49m ago) 7d10h 10.200.211.191 192.168.0.34
pod-demo 1/1 Running 1 (49m ago) 3h32m 10.200.155.138 192.168.0.36
test 1/1 Running 5 (49m ago) 14d 10.200.209.6 192.168.0.35
test1 1/1 Running 5 (49m ago) 14d 10.200.209.8 192.168.0.35
test2 1/1 Running 5 (49m ago) 14d 10.200.211.177 192.168.0.34
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
job-multi-demo-5vp9w 0/1 Completed 0 12s 10.200.211.144 192.168.0.34
job-multi-demo-frstg 0/1 Completed 0 22s 10.200.211.186 192.168.0.34
job-multi-demo-gd44s 0/1 Completed 0 17s 10.200.211.184 192.168.0.34
job-multi-demo-kfm79 0/1 ContainerCreating 0 2s 192.168.0.34
job-multi-demo-nsmpg 0/1 Completed 0 7s 10.200.211.135 192.168.0.34
net-test1 1/1 Running 3 (73m ago) 7d11h 10.200.211.191 192.168.0.34
pod-demo 1/1 Running 1 (73m ago) 3h56m 10.200.155.138 192.168.0.36
test 1/1 Running 5 (73m ago) 14d 10.200.209.6 192.168.0.35
test1 1/1 Running 5 (73m ago) 14d 10.200.209.8 192.168.0.35
test2 1/1 Running 5 (73m ago) 14d 10.200.211.177 192.168.0.34
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
job-multi-demo-5vp9w 0/1 Completed 0 33s 10.200.211.144 192.168.0.34
job-multi-demo-frstg 0/1 Completed 0 43s 10.200.211.186 192.168.0.34
job-multi-demo-gd44s 0/1 Completed 0 38s 10.200.211.184 192.168.0.34
job-multi-demo-kfm79 0/1 Completed 0 23s 10.200.211.140 192.168.0.34
job-multi-demo-nsmpg 0/1 Completed 0 28s 10.200.211.135 192.168.0.34
net-test1 1/1 Running 3 (73m ago) 7d11h 10.200.211.191 192.168.0.34
pod-demo 1/1 Running 1 (73m ago) 3h57m 10.200.155.138 192.168.0.36
test 1/1 Running 5 (73m ago) 14d 10.200.209.6 192.168.0.35
test1 1/1 Running 5 (73m ago) 14d 10.200.209.8 192.168.0.35
test2 1/1 Running 5 (73m ago) 14d 10.200.211.177 192.168.0.34
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
job-multi-demo-5vp9w 0/1 Completed 0 10m 10.200.211.144 192.168.0.34
job-multi-demo-frstg 0/1 Completed 0 11m 10.200.211.186 192.168.0.34
job-multi-demo-gd44s 0/1 Completed 0 11m 10.200.211.184 192.168.0.34
job-multi-demo-kfm79 0/1 Completed 0 10m 10.200.211.140 192.168.0.34
job-multi-demo-nsmpg 0/1 Completed 0 10m 10.200.211.135 192.168.0.34
job-multi-demo2-7ppxc 0/1 Completed 0 57s 10.200.211.145 192.168.0.34
job-multi-demo2-8bh22 0/1 Completed 0 47s 10.200.211.148 192.168.0.34
job-multi-demo2-dbjqw 0/1 Completed 0 47s 10.200.211.141 192.168.0.34
job-multi-demo2-mxbtq 0/1 Completed 0 52s 10.200.211.152 192.168.0.34
job-multi-demo2-rhgh7 0/1 Completed 0 51s 10.200.211.143 192.168.0.34
job-multi-demo2-th6ff 0/1 Completed 0 58s 10.200.211.136 192.168.0.34
net-test1 1/1 Running 3 (84m ago) 7d11h 10.200.211.191 192.168.0.34
pod-demo 1/1 Running 1 (84m ago) 4h7m 10.200.155.138 192.168.0.36
test 1/1 Running 5 (84m ago) 14d 10.200.209.6 192.168.0.35
test1 1/1 Running 5 (84m ago) 14d 10.200.209.8 192.168.0.35
test2 1/1 Running 5 (84m ago) 14d 10.200.211.177 192.168.0.34
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 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
ng-rc-wl5d6 1/1 Running 0 9s 10.200.155.185 192.168.0.36
test 1/1 Running 6 (11m ago) 16d 10.200.209.24 192.168.0.35
test1 1/1 Running 6 (11m ago) 16d 10.200.209.31 192.168.0.35
test2 1/1 Running 6 (11m ago) 16d 10.200.211.186 192.168.0.34
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



Welcome to nginx!



Welcome to nginx!

If you see this page, the nginx web server is successfully installed and working. Further configuration is required.

For online documentation and support please refer to nginx.org.
Commercial support is available at nginx.com.

Thank you for using nginx.




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 10.100.0.1 443/TCP 16d
ngx-nodeport-svc NodePort 10.100.209.225 80:30012/TCP 11s
root@k8s-deploy:/yaml# kubectl describe svc ngx-nodeport-svc
Name: ngx-nodeport-svc
Namespace: default
Labels:
Annotations:
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:
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



Welcome to nginx!



Welcome to nginx!

If you see this page, the nginx web server is successfully installed and working. Further configuration is required.

For online documentation and support please refer to nginx.org.
Commercial support is available at nginx.com.

Thank you for using nginx.




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



Welcome to nginx!



Welcome to nginx!

If you see this page, the nginx web server is successfully installed and working. Further configuration is required.

For online documentation and support please refer to nginx.org.
Commercial support is available at nginx.com.

Thank you for using nginx.




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 10.100.0.1 443/TCP 18d
ngx-nfs-svc NodePort 10.100.16.14 80:30013/TCP 15s
ngx-nodeport-svc NodePort 10.100.209.225 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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