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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