Day04-标签管理，livenessProbe探针，namespace名称空间，rc控制器及svc服务发现实战案例

0、上周内容回顾:

- Kubernetes集群部署
	- kubeadm
	- 二进制
		
     ---->: 
	     kind
		....
		
- k8S架构:
	- Controller Plane
		作用： 管理整套K8S集群的控制面板。
	- api-server:
		集群的统一访问入口。
	- etcd:
		存储集群数据。
	- scheduler:
		负责Pod的调度。
	- Controller Manager:
		维护集群的状态的。
			
	- worker Node:
		作用: 实际干活的节点。
	- kubelet:
		负责Pod的生命周期。
	- kube-proxy:
		负责对K8S集群外部提供访问路由。
	
    - Pod的基础管理
		- 什么是Pod:
			是K8S集群部署的最小单元。实际运行业务的地方。
		- 资源清单
		apiVersion: v1
		kind: Pod
		metadata:
			name: oldboyedu-linux85
		spec:
		    imagePullSecrets:
			- name:
			nodeName:
		    hostNetwork:
			volumes:
			- name:
			  emptyDir:{}
			- name:
			  hostPath:
			- name:
			  nfs:
				server:
				path:
			- name:
			  configMap:
			- name:
			  secret:
			restartPolicy:
			containers:
			- name:
			  image:
			  ports:
			  - containerPort:
			    name:
				hostIP:
				hostPort:
				protocol:
			  stdin:
			  command:
			  args:
			  resources:
				requests:
					cpu:
					memory:
				limits:
			  env:
			  - name:
			    value:
			  - name:
				valueFrom:
			  imagePullPolicy:
			  volumeMounts:
			  - name:
			    mountPath:
			  - name:
			    mountPath:
				subPath:
		status:
	- configMap:
		- 主要应用于存储程序的配置文件。

     - secret:
         - 存储敏感信息。比如说用户名密码，证书文件等。

• 资源的基础管理:

kubectl create
kubectk delete
kubectl apply
kubectl get

• 故障排查相关命令

kubectl describe
kubectl logs
kubectl cp
kubectl exec	

• 查看帮助信息

kubectl explain

Q1: 请问harbor的secret创建是能否直接创建资源清单呢？

Q2: 请问Pod能否实现对容器的健康检查，如果服务有异常，直接重启？

Q3: 如何实现创建多个名为"oldboyedu-linux85"的Pod呢?

Q4: 如何实现当Pod的IP地址发生变化时，不影响这正常服务的使用呢？

Q5: 如何实现删除了Pod后，自动拉起的功能?“kubectl delete pods --all”

Q6: 能否实现不通过api-Server创建Pod呢?换句话说，不能使用"kubectl create|apply"创建Pod资源呢?

1、K8S的两类API

• 响应式:
  可以理解直接基于命令行的方式创建资源。换句话说，不通过配置文件创建资源。
• 声明式：
  可以理解为通过资源清单的方式创建资源。话句话说，通过配置文件创建资源。

1.1 举个例子，测试数据如下：

用户名: linux85
密  码: oldboyedu@linux85
邮  箱: linux85@oldboyedu.com
服务器: harbor.oldboyedu.com

1.1.1 通过响应式方式创建harbor的认证信息

kubectl create secret docker-registry linux85-harbor --docker-username=linux85 --docker-password=oldboyedu@linux85 --docker-email=linux85@oldboyedu.com --docker-server=harbor.oldboyedu.com

1.1.2 通过声明式方式创建harbor的认证信息

(1)原生JSON格式数据

{"auths":{"harbor.oldboyedu.com":{"username":"linux85","password":"oldboyedu@linux85","email":"linux85@oldboyedu.com","auth":"linux85:oldboyedu@linux85"}}}	

(2)对于认证信息进行编码

{"auths":{"harbor.oldboyedu.com":{"username":"linux85","password":"oldboyedu@linux85","email":"linux85@oldboyedu.com","auth":"bGludXg4NTpvbGRib3llZHVAbGludXg4NQ=="}}}

(3)对全量信息进行编码。

eyJhdXRocyI6eyJoYXJib3Iub2xkYm95ZWR1LmNvbSI6eyJ1c2VybmFtZSI6ImxpbnV4ODUiLCJwYXNzd29yZCI6Im9sZGJveWVkdUBsaW51eDg1IiwiZW1haWwiOiJsaW51eDg1QG9sZGJveWVkdS5jb20iLCJhdXRoIjoiYkdsdWRYZzROVHB2YkdSaWIzbGxaSFZBYkdsdWRYZzROUT09In19fQ==

(4)编写资源清单

apiVersion: v1
data:
  .dockerconfigjson: eyJhdXRocyI6eyJoYXJib3Iub2xkYm95ZWR1LmNvbSI6eyJ1c2VybmFtZSI6ImxpbnV4ODUiLCJwYXNzd29yZCI6Im9sZGJveWVkdUBsaW51eDg1IiwiZW1haWwiOiJsaW51eDg1QG9sZGJveWVkdS5jb20iLCJhdXRoIjoiYkdsdWRYZzROVHB2YkdSaWIzbGxaSFZBYkdsdWRYZzROUT09In19fQ==
kind: Secret
metadata:
  name: linux85-harbor
type: kubernetes.io/dockerconfigjson

(5)创建资源清单

kubectl apply -f xxx.yaml

1.2 举个例子，测试数据如下：

用户名: linux86
密  码: oldboyedu@linux86
邮  箱: linux86@oldboyedu.com
服务器: harbor.oldboyedu.com 

1.2.1 通过声明式方式创建harbor的认证信息

(1)原生JSON格式数据

{"auths":{"harbor.oldboyedu.com":{"username":"linux86","password":"oldboyedu@linux86","email":"linux86@oldboyedu.com","auth":"linux86:oldboyedu@linux86"}}}

(2)对于认证信息("auth"资源)进行编码

[root@k8s231.oldboyedu.com secret]# echo -n linux86:oldboyedu@linux86 | base64 
bGludXg4NjpvbGRib3llZHVAbGludXg4Ng==
[root@k8s231.oldboyedu.com secret]# 

得到数据如下:

{"auths":{"harbor.oldboyedu.com":{"username":"linux86","password":"oldboyedu@linux86","email":"linux86@oldboyedu.com","auth":"bGludXg4NjpvbGRib3llZHVAbGludXg4Ng=="}}}

(3)对全量信息进行编码。（全量内容要使用单引号，否则就看不到文本的双引号啦~）

[root@k8s231.oldboyedu.com secret]# echo -n '{"auths":{"harbor.oldboyedu.com":{"username":"linux86","password":"oldboyedu@linux86","email":"linux86@oldboyedu.com","auth":"bGludXg4NjpvbGRib3llZHVAbGludXg4Ng=="}}}' | base64 
eyJhdXRocyI6eyJoYXJib3Iub2xkYm95ZWR1LmNvbSI6eyJ1c2VybmFtZSI6ImxpbnV4ODYiLCJwYXNzd29yZCI6Im9sZGJveWVkdUBsaW51eDg2IiwiZW1haWwiOiJsaW51eDg2QG9sZGJveWVkdS5jb20iLCJhdXRoIjoiYkdsdWRYZzROanB2YkdSaWIzbGxaSFZBYkdsdWRYZzROZz09In19fQ==
[root@k8s231.oldboyedu.com secret]# 

(4)编写资源清单

cat > harbor-linux86.yaml <<EOF
apiVersion: v1
data:
  .dockerconfigjson: eyJhdXRocyI6eyJoYXJib3Iub2xkYm95ZWR1LmNvbSI6eyJ1c2VybmFtZSI6ImxpbnV4ODYiLCJwYXNzd29yZCI6Im9sZGJveWVkdUBsaW51eDg2IiwiZW1haWwiOiJsaW51eDg2QG9sZGJveWVkdS5jb20iLCJhdXRoIjoiYkdsdWRYZzROanB2YkdSaWIzbGxaSFZBYkdsdWRYZzROZz09In19fQ==
kind: Secret
metadata:
  name: linux86-harbor
type: kubernetes.io/dockerconfigjson
EOF

(5)创建资源清单

kubectl apply -f harbor-linux86.yaml

(6)查看资源清单

[root@k8s231.oldboyedu.com secret]# kubectl get secrets linux86-harbor 
NAME             TYPE                             DATA   AGE
linux86-harbor   kubernetes.io/dockerconfigjson   1      2m29s

2、Pod的标签管理

2.1 响应式进行标签管理

• 创建标签

[root@k8s231.oldboyedu.com pods]# kubectl get pods --show-labels
NAME                     READY   STATUS    RESTARTS   AGE   LABELS
linux85-web-labels-001   1/1     Running   0          37s   <none>
[root@k8s231.oldboyedu.com pods]# kubectl label -f 13-web-labels.yaml school=oldboyedu
pod/linux85-web-labels-001 labeled
[root@k8s231.oldboyedu.com pods]# kubectl get pods --show-labels
NAME                     READY   STATUS    RESTARTS   AGE   LABELS
linux85-web-labels-001   1/1     Running   0          70s   school=oldboyedu
[root@k8s231.oldboyedu.com pods]# kubectl label pod linux85-web-labels-001 class=linux85
pod/linux85-web-labels-001 labeled
[root@k8s231.oldboyedu.com pods]# kubectl get pods --show-labels
NAME                     READY   STATUS    RESTARTS   AGE   LABELS
linux85-web-labels-001   1/1     Running   0          95s   class=linux85,school=oldboyedu

• 修改标签

[root@k8s231.oldboyedu.com pods]# kubectl get pods --show-labels
NAME                     READY   STATUS    RESTARTS   AGE     LABELS
linux85-web-labels-001   1/1     Running   0          3m44s   class=linux85,school=oldboyedu
[root@k8s231.oldboyedu.com pods]# kubectl label --overwrite pod linux85-web-labels-001 school=www.oldboyedu.com 
pod/linux85-web-labels-001 labeled
[root@k8s231.oldboyedu.com pods]# kubectl get pods --show-labels
NAME                     READY   STATUS    RESTARTS   AGE    LABELS
linux85-web-labels-001   1/1     Running   0          4m8s   class=linux85,school=www.oldboyedu.com

• 查看标签

[root@k8s231.oldboyedu.com pods]# kubectl get pods --show-labels
NAME                     READY   STATUS    RESTARTS   AGE    LABELS
linux85-web-labels-001   1/1     Running   0          4m8s   class=linux85,school=www.oldboyedu.com

• 删除标签

[root@k8s231.oldboyedu.com pods]# kubectl get pods --show-labels
NAME                     READY   STATUS    RESTARTS   AGE     LABELS
linux85-web-labels-001   1/1     Running   0          8m34s   class=linux85,school=www.oldboyedu.com
[root@k8s231.oldboyedu.com pods]# kubectl label pod linux85-web-labels-001 school- 
pod/linux85-web-labels-001 unlabeled
[root@k8s231.oldboyedu.com pods]# kubectl get pods --show-labels
NAME                     READY   STATUS    RESTARTS   AGE     LABELS
linux85-web-labels-001   1/1     Running   0          9m27s   class=linux85

2.2 基于声明式进行标签管理

[root@k8s231.oldboyedu.com pods]# cat 13-web-labels.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: linux85-web-labels-001
  labels:
    school: www.oldboyedu.com
    class: linux85
spec:
  containers:

  - name: nginx
    image: harbor.oldboyedu.com/web/nginx:1.20.1-alpine

[root@k8s231.oldboyedu.com pods]# kubectl get pods --show-labels
NAME                     READY   STATUS    RESTARTS   AGE   LABELS
linux85-web-labels-001   1/1     Running   0          22s   class=linux85,school=oldboyedu
[root@k8s231.oldboyedu.com pods]# kubectl apply -f 13-web-labels.yaml 
pod/linux85-web-labels-001 configured
[root@k8s231.oldboyedu.com pods]# kubectl get pods --show-labels
NAME                     READY   STATUS    RESTARTS   AGE   LABELS
linux85-web-labels-001   1/1     Running   0          35s   class=linux85,school=www.oldboyedu.com

对比标签管理，响应式和声明式的区别:

• 响应式:
  创建标签立即生效，但资源被重新创建时，标签可能会丢失哟~需要重新创建。
• 声明式:
  需要将标签写入到资源清单，每次修改后需要重新应用资源的配置文件，否则不会生效。

2.3 基于标签删除Pod资源案例

[root@k8s231.oldboyedu.com pods]# kubectl get pods --show-labels
NAME                     READY   STATUS    RESTARTS   AGE     LABELS
linux85-web              1/1     Running   0          45s     class=linux86
linux85-web-labels-001   1/1     Running   0          4m17s   class=linux85,school=www.oldboyedu.com
[root@k8s231.oldboyedu.com pods]# kubectl delete pods -l class=linux86 
pod "linux85-web" deleted
[root@k8s231.oldboyedu.com pods]# kubectl get pods --show-labels
NAME                     READY   STATUS    RESTARTS   AGE     LABELS
linux85-web-labels-001   1/1     Running   0          5m55s   class=linux85,school=www.oldboyedu.com

2.4 基于标签查看Pod

[root@k8s231.oldboyedu.com pods]# kubectl get pods --show-labels
NAME                     READY   STATUS    RESTARTS   AGE   LABELS
linux85-web              1/1     Running   0          32s   class=linux86
linux85-web-labels-001   1/1     Running   0          11m   class=linux85,school=www.oldboyedu.com
[root@k8s231.oldboyedu.com pods]# kubectl get pods -l class=linux85
NAME                     READY   STATUS    RESTARTS   AGE
linux85-web-labels-001   1/1     Running   0          12m

2.5 基于标签管理cm资源

[root@k8s231.oldboyedu.com pods]# kubectl get cm --show-labels
NAME                      DATA   AGE     LABELS
kube-root-ca.crt          1      4d21h   <none>
linux85-config            4      2d23h   <none>
oldboyedu-linux85-games   1      2d22h   <none> 
[root@k8s231.oldboyedu.com pods]# kubectl label cm oldboyedu-linux85-games school=oldboyedu
configmap/oldboyedu-linux85-games labeled
[root@k8s231.oldboyedu.com pods]# kubectl label cm linux85-config class=linux85
configmap/linux85-config labeled
[root@k8s231.oldboyedu.com pods]# kubectl get cm --show-labels
NAME                      DATA   AGE     LABELS
kube-root-ca.crt          1      4d21h   <none>
linux85-config            4      2d23h   class=linux85
oldboyedu-linux85-games   1      2d22h   school=oldboyedu 
[root@k8s231.oldboyedu.com pods]# kubectl label cm oldboyedu-linux85-games class=linux86
configmap/oldboyedu-linux85-games labeled
[root@k8s231.oldboyedu.com pods]# kubectl get cm -l class --show-labels
NAME                      DATA   AGE     LABELS
linux85-config            4      2d23h   class=linux85
oldboyedu-linux85-games   1      2d22h   class=linux86,school=oldboyedu
[root@k8s231.oldboyedu.com pods]# kubectl get cm -l class=linux85 --show-labels
NAME             DATA   AGE     LABELS
linux85-config   4      2d23h   class=linux85 

2.6 查看nodes节点的标签

[root@k8s231.oldboyedu.com pods]# kubectl get nodes --show-labels
NAME                   STATUS   ROLES                  AGE     VERSION    LABELS
k8s231.oldboyedu.com   Ready    control-plane,master   4d21h   v1.23.17   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s231.oldboyedu.com,kubernetes.io/os=linux,node-role.kubernetes.io/control-plane=,node-role.kubernetes.io/master=,node.kubernetes.io/exclude-from-external-load-balancers=
k8s232.oldboyedu.com   Ready    <none>                 4d21h   v1.23.17   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s232.oldboyedu.com,kubernetes.io/os=linux
k8s233.oldboyedu.com   Ready    <none>                 4d21h   v1.23.17   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=k8s233.oldboyedu.com,kubernetes.io/os=linux

3、探针(probe)常用的方式

3.1 常用的探针(Probe):

• livenessProbe:
  健康状态检查，周期性检查服务是否存活，检查结果失败，将"重启"容器(删除源容器并重新创建新容器)。
  如果容器没有提供健康状态检查，则默认状态为Success。
• readinessProbe:
  可用性检查，周期性检查服务是否可用，从而判断容器是否就绪。
  若检测Pod服务不可用，则会将Pod从svc的ep列表中移除。
  若检测Pod服务可用，则会将Pod重新添加到svc的ep列表中。
  如果容器没有提供可用性检查，则默认状态为Success。
• startupProbe: (1.16+之后的版本才支持)
  如果提供了启动探针，则所有其他探针都会被禁用，直到此探针成功为止。
  如果启动探测失败，kubelet将杀死容器，而容器依其重启策略进行重启。
  如果容器没有提供启动探测，则默认状态为 Success。

3.2 探针(Probe)检测Pod服务方法

exec:
执行一段命令，根据返回值判断执行结果。返回值为0或非0，有点类似于"echo $?"。
httpGet:
发起HTTP请求，根据返回的状态码来判断服务是否正常。
200: 返回状态码成功
301: 永久跳转
302: 临时跳转
401: 验证失败
403: 权限被拒绝
404: 文件找不到
413: 文件上传过大
500: 服务器内部错误
502: 无效的请求
504: 后端应用网关响应超时
…
tcpSocket:
测试某个TCP端口是否能够链接，类似于telnet，nc等测试工具。

参考链接:
​ https://kubernetes.io/zh/docs/concepts/workloads/pods/pod-lifecycle/#types-of-probe
​
​

3.3 健康检查(livenessProbe)-exec检测方法

cat > 14-livenessProbe-exec.yaml <<EOF
kind: Pod
apiVersion: v1
metadata:
  name: oldboyedu-linux85-exec-001
  labels:
     apps: myweb
spec:
  containers:
  - name: linux85-exec
    image: harbor.oldboyedu.com/web/nginx:1.20.1-alpine
    command: 
    - /bin/sh
    - -c
    - touch /tmp/oldboyedu-linux85-healthy; sleep 5; rm -f /tmp/oldboyedu-linux85-healthy; sleep 600
    # 健康状态检查，周期性检查服务是否存活，检查结果失败，将重启容器。
    livenessProbe:
      # 使用exec的方式去做健康检查
      exec:
        # 自定义检查的命令
        command:
        - cat
        - /tmp/oldboyedu-linux85-healthy
      # 检测服务失败次数的累加值，默认值是3次，最小值是1。当检测服务成功后，该值会被重置!
      failureThreshold: 3
      # 指定多久之后进行健康状态检查，即此时间段内检测服务失败并不会对failureThreshold进行计数。
      initialDelaySeconds: 15
      # 指定探针检测的频率，默认是10s，最小值为1.
      periodSeconds: 1
      # 检测服务成功次数的累加值，默认值为1次，最小值1.
      successThreshold: 1
      # 一次检测周期超时的秒数，默认值是1秒，最小值为1.
      timeoutSeconds: 1
EOF

温馨提示:
	在验证探针是否检查失败时，可以使用describe命令查看时间关于Reason内容包含"Unhealthy"所在的行，如下所示:
Events:
  Type     Reason     Age                     From                           Message
----     ------     ----                    ----                           -------
  Normal   Scheduled  6m5s                    default-scheduler              Successfully assigned         default/oldboyedu-linux81-exec-001 to k8s153.oldboyedu.com
  ......
  Warning  Unhealthy  3m23s (x10 over 5m47s)  kubelet, k8s153.oldboyedu.com  Liveness probe failed: cat: /tmp/oldboyedu-linux81-healthy: No such file or directory
  
注意观察:
“(x10 over 5m47s)”的内容，表示第10次检查失败，其中距离第一次检查失败已经经过了"5m47s"秒，而开始调度成功的时间是"6m5s"之前，两者时间差详见，得出第一次检测失败的时间是"18s".

• httpGet检测方法

cat > 15-livenessProbe-httpGet.yaml <<EOF
kind: Pod
apiVersion: v1
metadata:
  name: oldboyedu-linux85-httpget-001
  labels:
     apps: myweb
spec:
  volumes:
  - name: data
    emptyDir: {}
  containers:
  - name: linux85-httpget
    image: harbor.oldboyedu.com/web/nginx:1.20.1-alpine
    volumeMounts:
    - name: data
      mountPath: /usr/share/nginx/html
    # 健康状态检查，周期性检查服务是否存活，检查结果失败，将重启容器。
    livenessProbe:
      # 使用httpGet的方式去做健康检查
      httpGet:
        # 指定访问的端口号
        port: 80
        # 检测指定的访问路径
        path: /index.html
      # 检测服务失败次数的累加值，默认值是3次，最小值是1。当检测服务成功后，该值会被重置!
      failureThreshold: 3
      # 指定多久之后进行健康状态检查，即此时间段内检测服务失败并不会对failureThreshold进行计数。
      initialDelaySeconds: 65
      # 指定探针检测的频率，默认是10s，最小值为1.
      periodSeconds: 1
      # 检测服务成功次数的累加值，默认值为1次，最小值1.
      successThreshold: 1
      # 一次检测周期超时的秒数，默认值是1秒，最小值为1.
      timeoutSeconds: 1
EOF

• tcpSocket检测方法

cat > 16-livenessProbe-tcpSocket.yaml <<EOF
kind: Pod
apiVersion: v1
metadata:
  name: oldboyedu-linux85-tcpsocket-001
  labels:
     apps: myweb
spec:
  containers:
  - name: linux85-tcpsocket
    image: harbor.oldboyedu.com/web/nginx:1.20.1-alpine
    command:
    - /bin/sh
    - -c
    - nginx ; sleep 10; nginx -s stop ; sleep 600
    # 健康状态检查，周期性检查服务是否存活，检查结果失败，将重启容器。
    livenessProbe:
      # 使用tcpSocket的方式去做健康检查
      tcpSocket:
        port: 80
      # 检测服务失败次数的累加值，默认值是3次，最小值是1。当检测服务成功后，该值会被重置!
      failureThreshold: 3
      # 指定多久之后进行健康状态检查，即此时间段内检测服务失败并不会对failureThreshold进行计数。
      initialDelaySeconds: 15
      # 指定探针检测的频率，默认是10s，最小值为1.
      periodSeconds: 1
      # 检测服务成功次数的累加值，默认值为1次，最小值1.
      successThreshold: 1
      # 一次检测周期超时的秒数，默认值是1秒，最小值为1.
      timeoutSeconds: 1
EOF

在同一个名称空间下，同一种资源类型，是无法同时创建多个名称相同的资源。

yumeng: oldboyedu-linux85

liwenxuan: oldboyedu-linux85

名称空间是用来隔离K8S集群的资源。我们通常使用名称空间对企业业务进行逻辑上划分。

K8S集群一切皆资源，有的资源是不支持名称空间的，我们将其称为全局资源，而支持名称空间的资源我们称之为局部资源。

我们可以通过"kubectl api-resources"命令来判断一个资源是否支持名称空间。

温馨提示:
（1）在同一个名称空间下，同一个资源类型是不能出现重名的;
（2）在不同的名称空间下，相同的资源类型是能出现同名的;

4、名称空间的基本管理

4.1 名称空间的资源查看详解

1.查看现象有的名称空间

[root@k8s231.oldboyedu.com pods]# kubectl get namespaces 

2.查看默认名称空间的Pod资源

kubectl get pods -n default
kubectl get pods 

3.查看指定的名称空间Pod资源

kubectl get pods -n kube-system
kubectl get pods --namespace kube-system

4.查看所有名称空间的Pod资源

kubectl get pods --all-namespaces
kubectl get pods -A	

5.查看所有名称空间的cm资源

kubectl get cm -A

6.查看指定名称空间的cm资源

kubectl get cm -n kube-system

4.2 创建名称空间

1.响应式创建名称空间

kubectl create namespace oldboyedu-linux85

2.声明式创建名称空间

[root@k8s231.oldboyedu.com namespaces]# cat 01-ns.yaml 
apiVersion: v1
kind: Namespace
metadata:
  name: oldboyedu-linux86
  labels:
    school: oldboyedu
    class: linux86
[root@k8s231.oldboyedu.com namespaces]# 

4.3 修改名称空间

名称空间一旦创建将无法修改！

4.4 使用名称空间

[root@k8s231.oldboyedu.com namespaces]# cat 02-pods-ns.yaml 
apiVersion: v1
kind: Pod
metadata:
  name: linux85-web
  # 指定资源所在的名称空间
  namespace: oldboyedu-linux85
spec:
  containers:
  - name: nginx
    image: nginx:1.14.2
[root@k8s231.oldboyedu.com namespaces]# 
[root@k8s231.oldboyedu.com namespaces]# cat 03-cm-ns.yaml 
apiVersion: v1
kind: ConfigMap
metadata:
  name: linux85-config
  namespace: oldboyedu-linux85
data:
   school: oldboyedu
   class: linux85

   my.cfg: |
     datadir: "/var/lib/mysql"
     basedir: "/usr/share/mysql"
     socket: "/tmp/mysql.sock"

   student.info: |
     pengbing: "大长腿，熬夜，六味地黄丸"
     wumingkun: "彭斌,Linux"
     qinhongbin: "欧美,日韩,国产"
     liwenxuan: "拍小电影,小皮鞭"
     wanglei: "演小电影,大皮鞭"
[root@k8s231.oldboyedu.com namespaces]# 
[root@k8s231.oldboyedu.com namespaces]# 
[root@k8s231.oldboyedu.com namespaces]# cat 04-secret-ns.yaml 
apiVersion: v1
kind: Secret
metadata:
  name: es-https
  namespace: oldboyedu-linux85
data:
  username: ZWxhc3RpYwo=
  password: b2xkYm95ZWR1Cg==
  hostip: MTAuMC4wLjI1MAo=
[root@k8s231.oldboyedu.com namespaces]# 

4.5 删除名称空间注意事项，一旦删除名称空间，该名称空间下的所有资源都会被随之删除哟！

[root@k8s231.oldboyedu.com namespaces]# kubectl get po,cm,secret -n oldboyedu-linux85
NAME              READY   STATUS    RESTARTS   AGE
pod/linux85-web   1/1     Running   0          6m9s

NAME                         DATA   AGE
configmap/kube-root-ca.crt   1      13m
configmap/linux85-config     4      5m10s

NAME                         TYPE                                  DATA   AGE
secret/default-token-mgnq5   kubernetes.io/service-account-token   3      13m
secret/es-https              Opaque                                3      4m5s
 
[root@k8s231.oldboyedu.com namespaces]# kubectl delete namespace oldboyedu-linux85
namespace "oldboyedu-linux85" deleted
[root@k8s231.oldboyedu.com namespaces]# kubectl get po,cm,secret -n oldboyedu-linux85
No resources found in oldboyedu-linux85 namespace.

5、rc控制器实战案例

[root@k8s231.oldboyedu.com replicationcontrollers]# cat 01-rc-nginx.yaml 
apiVersion: v1
kind: ReplicationController
metadata:
  name: oldboyedu-linux85-web-rc
  labels:
    school: oldboyedu
    class: linux85
    apps: rc
  namespace: default
spec:
  # 指定Pod的副本数量，默认值为1
  replicas: 5
  # 指定标签选择器
  selector:
     classroom: jiaoshi05
     address: oldboyedu-shahe
  # 指定创建Pod的模板
  template:
    metadata:
      labels:
        classroom: jiaoshi05
        address: oldboyedu-shahe
        hobby: k8s
        auther: jasonyin
    spec:
      containers:
      - name: nginx
        image: harbor.oldboyedu.com/web/nginx:1.20.1-alpine 
        
[root@k8s231 replicationcontrollers]# kubectl get pods -o wide
NAME                             READY   STATUS    RESTARTS   AGE   IP            NODE                   NOMINATED NODE   READINESS GATES
oldboyedu-linux85-web-rc-bpk5t   1/1     Running   0          12s   10.100.2.22   k8s233.oldboyedu.com   <none>           <none>
oldboyedu-linux85-web-rc-kn6vq   1/1     Running   0          12s   10.100.2.21   k8s233.oldboyedu.com   <none>           <none>
oldboyedu-linux85-web-rc-vkvm8   1/1     Running   0          12s   10.100.2.23   k8s233.oldboyedu.com   <none>           <none>
oldboyedu-linux85-web-rc-vmpgl   1/1     Running   0          12s   10.100.1.36   k8s232.oldboyedu.com   <none>           <none>
oldboyedu-linux85-web-rc-vsvr5   1/1     Running   0          12s   10.100.1.37   k8s232.oldboyedu.com   <none>           <none>
[root@k8s231 replicationcontrollers]# kubectl get pods --show-labels 
NAME                             READY   STATUS    RESTARTS   AGE   LABELS
oldboyedu-linux85-web-rc-bpk5t   1/1     Running   0          74s   address=oldboyedu-shahe,auther=jasonyin,classroom=jiaoshi05,hobby=k8s
oldboyedu-linux85-web-rc-kn6vq   1/1     Running   0          74s   address=oldboyedu-shahe,auther=jasonyin,classroom=jiaoshi05,hobby=k8s
oldboyedu-linux85-web-rc-vkvm8   1/1     Running   0          74s   address=oldboyedu-shahe,auther=jasonyin,classroom=jiaoshi05,hobby=k8s
oldboyedu-linux85-web-rc-vmpgl   1/1     Running   0          74s   address=oldboyedu-shahe,auther=jasonyin,classroom=jiaoshi05,hobby=k8s
oldboyedu-linux85-web-rc-vsvr5   1/1     Running   0          74s   address=oldboyedu-shahe,auther=jasonyin,classroom=jiaoshi05,hobby=k8s
[root@k8s231 replicationcontrollers]# kubectl delete pods --all
pod "oldboyedu-linux85-web-rc-bpk5t" deleted
pod "oldboyedu-linux85-web-rc-kn6vq" deleted
pod "oldboyedu-linux85-web-rc-vkvm8" deleted
pod "oldboyedu-linux85-web-rc-vmpgl" deleted
pod "oldboyedu-linux85-web-rc-vsvr5" deleted
[root@k8s231 replicationcontrollers]# kubectl get pods --show-labels 
NAME                             READY   STATUS    RESTARTS   AGE   LABELS
oldboyedu-linux85-web-rc-dpp9w   1/1     Running   0          4s    address=oldboyedu-shahe,auther=jasonyin,classroom=jiaoshi05,hobby=k8s
oldboyedu-linux85-web-rc-jwcsq   1/1     Running   0          4s    address=oldboyedu-shahe,auther=jasonyin,classroom=jiaoshi05,hobby=k8s
oldboyedu-linux85-web-rc-lpzbs   1/1     Running   0          4s    address=oldboyedu-shahe,auther=jasonyin,classroom=jiaoshi05,hobby=k8s
oldboyedu-linux85-web-rc-rrr5r   1/1     Running   0          4s    address=oldboyedu-shahe,auther=jasonyin,classroom=jiaoshi05,hobby=k8s
oldboyedu-linux85-web-rc-tb99x   1/1     Running   0          4s    address=oldboyedu-shahe,auther=jasonyin,classroom=jiaoshi05,hobby=k8s
[root@k8s231 replicationcontrollers]# kubectl get pods -o wide
NAME                             READY   STATUS    RESTARTS   AGE   IP            NODE                   NOMINATED NODE   READINESS GATES
oldboyedu-linux85-web-rc-dpp9w   1/1     Running   0          11s   10.100.1.40   k8s232.oldboyedu.com   <none>           <none>
oldboyedu-linux85-web-rc-jwcsq   1/1     Running   0          11s   10.100.1.38   k8s232.oldboyedu.com   <none>           <none>
oldboyedu-linux85-web-rc-lpzbs   1/1     Running   0          11s   10.100.2.25   k8s233.oldboyedu.com   <none>           <none>
oldboyedu-linux85-web-rc-rrr5r   1/1     Running   0          11s   10.100.2.24   k8s233.oldboyedu.com   <none>           <none>
oldboyedu-linux85-web-rc-tb99x   1/1     Running   0          11s   10.100.1.39   k8s232.oldboyedu.com   <none>           <none>
[root@k8s231 replicationcontrollers]# kubectl get all
NAME                                 READY   STATUS    RESTARTS   AGE
pod/oldboyedu-linux85-web-rc-dpp9w   1/1     Running   0          68s
pod/oldboyedu-linux85-web-rc-jwcsq   1/1     Running   0          68s
pod/oldboyedu-linux85-web-rc-lpzbs   1/1     Running   0          68s
pod/oldboyedu-linux85-web-rc-rrr5r   1/1     Running   0          68s
pod/oldboyedu-linux85-web-rc-tb99x   1/1     Running   0          68s

NAME                                             DESIRED   CURRENT   READY   AGE
replicationcontroller/oldboyedu-linux85-web-rc   5         5         5       3m17s

NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
service/kubernetes   ClusterIP   10.200.0.1   <none>        443/TCP   8d
[root@k8s231 replicationcontrollers]# kubectl delete replicationcontroller/oldboyedu-linux85-web-rc
replicationcontroller "oldboyedu-linux85-web-rc" deleted
[root@k8s231 replicationcontrollers]# kubectl get all
NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
service/kubernetes   ClusterIP   10.200.0.1   <none>        443/TCP   8d

自定义Pod实战案例:

[root@k8s231.oldboyedu.com replicationcontrollers]# cat /tmp/pods.yaml 
apiVersion: v1
kind: Pod
metadata:
  labels:
    address: oldboyedu-shahe
    auther: jasonyin
    classroom: jiaoshi05
    hobby: k8s
    apps: web01
  name: oldboyedu-linux85-jiaoshi07
  namespace: default
spec:
  containers:
  - image: harbor.oldboyedu.com/web/nginx:1.20.1-alpine
    name: nginx
[root@k8s231.oldboyedu.com replicationcontrollers]# 

6、SVC的ClusterIP类型

[root@k8s231.oldboyedu.com services]# cat 01-svc-ClusterIP.yaml 
apiVersion: v1
kind: Service
metadata:
  name: oldboyedu-linux85-web
  namespace: default
  labels:
    apps: oldboyedu-svc
    class: linux85
spec:
  # 关联后端的Pod
  selector:
    hobby: k8s
    auther: jasonyin
  # 指定svc的类型，有效值为: ExternalName, ClusterIP, NodePort, and LoadBalancer
  #    ExternalName:
  #       可以将K8S集群外部的服务映射为一个svc服务。类似于一种CNAME技术.
  #    ClusterIP:
  #       仅用于K8S集群内部使用。提供统一的VIP地址。默认值！
  #    NodePort:
  #       基于ClusterIP基础之上，会监听所有的Worker工作节点的端口，K8S外部可以基于监听端口访问K8S内部服务。
  #    LoadBalancer:
  #       主要用于云平台的LB等产品。
  type: ClusterIP
  # 指定端口映射相关信息
  ports:
    # 指定svc的端口号
  - port: 88
    # 指定Pod端口号
    targetPort: 80
    # 指定协议
    protocol: TCP
  # 指定ClusterIP的地址
  clusterIP: 10.200.100.100
[root@k8s231 service]# kubectl apply -f 01-svc-ClusterIP.yaml 
service/oldboyedu-linux85-web created
[root@k8s231 service]# kubectl get svc
NAME                    TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE
  bernetes              ClusterIP   10.200.0.1      <none>        443/TCP   8d
oldboyedu-linux85-web   ClusterIP   10.200.93.185   <none>        88/TCP    9s
[root@k8s231 service]# kubectl get svc -o wide
NAME                    TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE   SELECTOR
kubernetes              ClusterIP   10.200.0.1      <none>        443/TCP   8d    <none>
oldboyedu-linux85-web   ClusterIP   10.200.93.185   <none>        88/TCP    18s   auther=jasonyin,hobby=k8s
[root@k8s231 service]# kubectl describe svc oldboyedu-linux85-web 
Name:              oldboyedu-linux85-web
Namespace:         default
Labels:            apps=oldboyedu-svc
                   class=linux85
Annotations:       <none>
Selector:          auther=jasonyin,hobby=k8s
Type:              ClusterIP
IP Family Policy:  SingleStack
IP Families:       IPv4
IP:                10.200.93.185
IPs:               10.200.93.185
Port:              <unset>  88/TCP
TargetPort:        80/TCP
Endpoints:         10.100.1.44:80,10.100.2.30:80
Session Affinity:  None
Events:            <none>
[root@k8s231 service]# kubectl get po -o wide --show-labels 
NAME                             READY   STATUS    RESTARTS   AGE   IP            NODE                   NOMINATED NODE   READINESS GATES   LABELS
oldboyedu-linux85-web-rc-68x5g   1/1     Running   0          65s   10.100.2.30   k8s233.oldboyedu.com   <none>           <none>            address=oldboyedu-shahe,auther=jasonyin,classroom=jiaoshi05,hobby=k8s
oldboyedu-linux85-web-rc-m27f5   1/1     Running   0          65s   10.100.1.44   k8s232.oldboyedu.com   <none>           <none>            address=oldboyedu-shahe,auther=jasonyin,classroom=jiaoshi05,hobby=k8s
[root@k8s231 service]# curl 10.200.93.185:88
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
    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@k8s231 service]# kubectl exec -it oldboyedu-linux85-web-rc-68x5g -- sh
/ # cd /usr/share/nginx/html/
/usr/share/nginx/html # echo "web01 10.100.2.30" > index.html 
/usr/share/nginx/html # 
[root@k8s231 service]# kubectl exec -it oldboyedu-linux85-web-rc-m27f5 -- sh
/ # cd /usr/share/nginx/html/
/usr/share/nginx/html # ll
sh: ll: not found
/usr/share/nginx/html # ls
50x.html    index.html
/usr/share/nginx/html # echo "web02 10.100.1.44" > index.html 
/usr/share/nginx/html # 
[root@k8s231 service]# curl 10.200.93.185:88
web02 10.100.1.44
[root@k8s231 service]# curl 10.200.93.185:88
web01 10.100.2.30
[root@k8s231 service]# curl 10.200.93.185:88
web02 10.100.1.44
[root@k8s231 service]# curl 10.200.93.185:88
web02 10.100.1.44
[root@k8s231 service]# 

SVC的两大特性：

• 对外提供负载均衡能力
• 对内提供服务发现功能

今日作业:
(1)完成课堂的所有练习并整理思维导图；
(2)将上周作业使用rc资源实现，并通过svc访问，要求将这些资源都放在"oldboyedu-homework"名称空间下;

扩展作业:
使用各组部署的K8S组件实现将作业迁移到你部署的集群即可.