k8s资源对象

作者：Linux-1874

1792 次浏览

15 次

2023-5-12

编辑推荐:

本文主要介绍了k8s资源对象、k8s逻辑运行环境、k8s的设计理念等相关知识。希望对你的学习有帮助。
本文来自于博客园，由Linda编辑、推荐。

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:

namespace: default

labels:

app: job-demo

spec:

template:

metadata:

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: 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:

namespace: default

labels:

app: job-multi-demo

spec:

completions: 5

template:

metadata:

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: 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:

namespace: default

labels:

app: job-multi-demo2

spec:

completions: 6

parallelism: 2

template:

metadata:

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: 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:

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: 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:

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

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:

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:

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

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:

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:

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:

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

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:

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:

namespace: default<br>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:

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:

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

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:

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:

---

apiVersion: v1

kind: ServiceAccount

metadata:

# replace with namespace where provisioner is deployed

namespace: nfs

---

kind: ClusterRole

apiVersion: rbac.authorization.k8s.io/v1

metadata:

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:

subjects:

- kind: ServiceAccount

# replace with namespace where provisioner is deployed

namespace: nfs

roleRef:

kind: ClusterRole

apiGroup: rbac.authorization.k8s.io

---

kind: Role

apiVersion: rbac.authorization.k8s.io/v1

metadata:

# 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:

# replace with namespace where provisioner is deployed

namespace: nfs

subjects:

- kind: ServiceAccount

# replace with namespace where provisioner is deployed

namespace: nfs

roleRef:

kind: Role

apiGroup: rbac.authorization.k8s.io

创建sc

apiVersion: storage.k8s.io/v1

kind: StorageClass

metadata:

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:

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:

---

# Test PVC

kind: PersistentVolumeClaim

apiVersion: v1

metadata:

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

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"

volumes:

- name: statics-datadir

persistentVolumeClaim:

claimName: myserver-myapp-dynamic-pvc

---

kind: Service

apiVersion: v1

metadata:

labels:

app: myserver-myapp-service

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。

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