Pod是可以創建和管理Kubernetes計算的最小可部署單元,一個Pod代表着集羣
中運行的一個進程,每個pod都有一個唯一的ip。
一個pod類似一個豌豆莢,包含一個或多個容器(通常是docker),多個容器間共享IPC、Network和UTC namespace。

pod運行管理

自主式pod

[kubeadm@server2 ~]$ kubectl run demo --image=nginx
pod/demo created
[kubeadm@server2 ~]$ kubectl  get pods
NAME   READY   STATUS    RESTARTS   AGE
demo   1/1     Running   0          8s
[kubeadm@server2 ~]$ kubectl  get pods -o wide
NAME   READY   STATUS    RESTARTS   AGE   IP           NODE      NOMINATED NODE   READINESS GATES
demo   1/1     Running   0          14s   10.244.1.5   server3   <none>           <none>
[kubeadm@server2 ~]$ kubectl delete pod demo 
pod "demo" deleted
[kubeadm@server2 ~]$ kubectl  get pods -o wide
No resources found in default namespace.

自主式pod 刪除後就沒有了，生命週期就結束了。

deployment控制器

[kubeadm@server2 ~]$ kubectl create deployment myapp --image=nginx
deployment.apps/myapp created
[kubeadm@server2 ~]$ kubectl get pod
NAME                     READY   STATUS    RESTARTS   AGE
myapp-687598b8b4-678wm   1/1     Running   0          4s

生成的pod名稱是控制器名稱myapp + rs名 +容器名,而且我們還可以再後面加參數，指定副本數等。

[kubeadm@server2 ~]$ kubectl get pod
NAME                     READY   STATUS    RESTARTS   AGE
myapp-687598b8b4-678wm   1/1     Running   0          4s
[root@server3 ~]# ip a
5: cni0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue state UP group default qlen 1000
    link/ether c6:c8:cf:99:c7:2d brd ff:ff:ff:ff:ff:ff
    inet 10.244.1.1/24 scope global cni0		# pod再結點上運行會創建cni0網卡，分配ip。
       valid_lft forever preferred_lft forever
    inet6 fe80::c4c8:cfff:fe99:c72d/64 scope link 
       valid_lft forever preferred_lft forever
[kubeadm@server2 ~]$ kubectl delete pod myapp-687598b8b4-678wm 
pod "myapp-687598b8b4-678wm" deleted
[kubeadm@server2 ~]$ get pod
NAME                     READY   STATUS    RESTARTS   AGE
myapp-687598b8b4-bt8mv   1/1     Running   0          10s

我們刪除了之前的，但是deploy控制器直接再相同的rs底下拉取了一個副本.

[kubeadm@server2 ~]$ kubectl get all
NAME                         READY   STATUS    RESTARTS   AGE	
pod/myapp-687598b8b4-bt8mv   1/1     Running   0          97s	# pod
	
NAME                 TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
service/kubernetes   ClusterIP   10.96.0.1    <none>        443/TCP   17h

NAME                    READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/myapp   1/1     1            1           4m42s	#deployment控制器

NAME                               DESIRED   CURRENT   READY   AGE
replicaset.apps/myapp-687598b8b4   1         1         1       4m41s	#rs控制器
#pod出現故障的時候，rs 控制器會進行修復。

那我們想刪除它的話，就需要刪除調度器纔可以：

[kubeadm@server2 ~]$ kubectl delete deployments.apps myapp
deployment.apps "myapp" deleted

[kubeadm@server2 ~]$ kubectl get pod
No resources found in default namespace.

pod的擴容縮容：

[kubeadm@server2 ~]$ kubectl create deployment myapp --image=nginx
deployment.apps/myapp created
[kubeadm@server2 ~]$ kubectl get pod
NAME                     READY   STATUS    RESTARTS   AGE
myapp-687598b8b4-mjhdc   1/1     Running   0          9s
[kubeadm@server2 ~]$ kubectl scale deployment myapp --replicas=2
deployment.apps/myapp scaled		# 拉伸到2個
[kubeadm@server2 ~]$ kubectl get pod
NAME                     READY   STATUS              RESTARTS   AGE
myapp-687598b8b4-c6s7h   0/1     ContainerCreating   0          1s
myapp-687598b8b4-mjhdc   1/1     Running             0          33s
[kubeadm@server2 ~]$ kubectl scale deployment myapp --replicas=10
deployment.apps/myapp scaled		# 拉伸到10個
[kubeadm@server2 ~]$ kubectl get pod
NAME                     READY   STATUS              RESTARTS   AGE
myapp-687598b8b4-2wttr   0/1     ContainerCreating   0          1s
myapp-687598b8b4-84k69   0/1     Pending             0          1s
myapp-687598b8b4-b2w99   0/1     ContainerCreating   0          1s
myapp-687598b8b4-c6s7h   1/1     Running             0          5s
myapp-687598b8b4-h6lph   0/1     Pending             0          1s
myapp-687598b8b4-mjhdc   1/1     Running             0          37s
myapp-687598b8b4-whld2   0/1     Pending             0          1s
myapp-687598b8b4-wtpkn   0/1     Pending             0          1s
myapp-687598b8b4-xx8qr   0/1     Pending             0          1s
myapp-687598b8b4-zkwc9   0/1     ContainerCreating   0          1s
[kubeadm@server2 ~]$ kubectl scale deployment myapp --replicas=2
deployment.apps/myapp scaled
[kubeadm@server2 ~]$ kubectl get pod
NAME                     READY   STATUS        RESTARTS   AGE
myapp-687598b8b4-hb7zv   1/1     Running       0          11s
myapp-687598b8b4-s2ncv   1/1     Running       0          18s

[kubeadm@server2 ~]$ kubectl delete deployments.apps myapp 
deployment.apps "myapp" deleted
[kubeadm@server2 ~]$ kubectl get pod
No resources found in default namespace.		# 可以這樣刪除

這就是我們手動的擴容。其實可以做到再需求比較大的時候自動擴容，再需求小的時候再自動縮容。

service微服務

[kubeadm@server2 ~]$ curl 10.244.1.15
<!DOCTYPE html>
<html>
<head>
 當前我們是可以通過內網來訪問開啓的容器的

service是一個抽象概念,定義了一個服務的多個pod邏輯合集和訪問pod的策略,一般把service稱爲微服務。
service 就是來暴露我們的訪問接口的，它就是從外部訪問內部pod的一個端口port，並且可以實現負載均衡。

創建service

[root@server2 ~]# kubectl expose deployment myapp --port=80 --target-port=80
service/myapp exposed		# 相當於端口映射
[root@server2 ~]# kubectl get svc
NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE
kubernetes   ClusterIP   10.96.0.1       <none>        443/TCP   19h
myapp        ClusterIP   10.109.116.35   <none>        80/TCP    9s
默認獲得一個clusterIP 類型，這是一個僅集羣內部可以訪問的虛擬IP.

[root@server2 ~]# kubectl describe svc myapp
Name:              myapp
Namespace:         default
Labels:            app=myapp
Annotations:       <none>
Selector:          app=myapp
Type:              ClusterIP
IP:                10.109.116.35		# service 分到的IP
Port:              <unset>  80/TCP
TargetPort:        80/TCP
Endpoints:         10.244.1.15:80,10.244.2.6:80		# 這裏的兩個ip地址和pod的ip相同，是虛擬ip
Session Affinity:  None
Events:            <none>
[root@server2 ~]# kubectl get pod -o wide
NAME                     READY   STATUS    RESTARTS   AGE   IP            NODE      NOMINATED NODE   READINESS GATES
myapp-687598b8b4-hb7zv   1/1     Running   0          53m   10.244.2.6    server4   <none>           <none>
myapp-687598b8b4-s2ncv   1/1     Running   0          54m   10.244.1.15   server3   <none>           <none>

它是怎麼識別pod的那？
[root@server2 ~]# kubectl get pod --show-labels 
NAME                     READY   STATUS    RESTARTS   AGE   LABELS
myapp-687598b8b4-hb7zv   1/1     Running   0          56m   app=myapp,pod-template-hash=687598b8b4
myapp-687598b8b4-s2ncv   1/1     Running   0          56m   app=myapp,pod-template-hash=687598b8b4
															#是通過後面的標籤識別的，有這個標籤，就可以加進來

比如：
[root@server2 ~]# kubectl scale deployment myapp --replicas=4		# 我們擴增到四個
deployment.apps/myapp scaled
[root@server2 ~]# kubectl get pod --show-labels 
NAME                     READY   STATUS    RESTARTS   AGE   LABELS
myapp-687598b8b4-hb7zv   1/1     Running   0          58m   app=myapp,pod-template-hash=687598b8b4
myapp-687598b8b4-px6nq   1/1     Running   0          9s    app=myapp,pod-template-hash=687598b8b4
myapp-687598b8b4-s2ncv   1/1     Running   0          58m   app=myapp,pod-template-hash=687598b8b4
myapp-687598b8b4-tkhv5   1/1     Running   0          9s    app=myapp,pod-template-hash=687598b8b4
# 每個都有標籤

[root@server2 ~]# kubectl describe svc myapp
Name:              myapp
Namespace:         default
Labels:            app=myapp
Annotations:       <none>
Selector:          app=myapp
Type:              ClusterIP
IP:                10.109.116.35
Port:              <unset>  80/TCP
TargetPort:        80/TCP
Endpoints:         10.244.1.15:80,10.244.1.19:80,10.244.2.6:80 + 1 more...	# ip 動態加進來了。
Session Affinity:  None
Events:            <none>

由於後端由多個，我們就可以通過service的 虛擬IP地址進行訪問，並可以實現負載均衡。
但是現在還不能使用VIP 進行訪問，我們還沒有配置好，我們可以去容器內部訪問一下;

[root@server2 ~]# kubectl run demo --image=busyboxplus -it  --restart=never
If you don't see a command prompt, try pressing enter.
/ # curl 10.109.116.35
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>		#這裏做負載均衡效果不明顯,我們在版本更新處展示

滾動更新

更新

[root@server2 ~]# kubectl get pod		# 這是我們現在運行的容器
NAME                     READY   STATUS    RESTARTS   AGE
demo                     1/1     Running   1          8m58s
myapp-687598b8b4-hb7zv   1/1     Running   0          92m
myapp-687598b8b4-px6nq   1/1     Running   0          34m
myapp-687598b8b4-s2ncv   1/1     Running   0          92m
myapp-687598b8b4-tkhv5   1/1     Running   0          34m

[root@server2 ~]# kubectl describe pod myapp-687598b8b4-hb7zv 
Containers:
  nginx:			# 裏面運行的容器名字叫做nginx
    Container ID:   docker://fef76a437c55b9ea9c9c089bdcddd21b0eb0e737c88125c237f56188e8c74104
    Image:          nginx		# 鏡像是nginx

[root@server2 ~]# kubectl set image deployments myapp nginx=myapp:v1 --record		# 更新
deployment.apps/myapp image updated			# record 是記錄，用於回滾
[root@server2 ~]# kubectl get pod

NAME                     READY   STATUS    RESTARTS   AGE
demo                     1/1     Running   1          19m
myapp-76df559f68-bjwwx   1/1     Running   0          3m52s
myapp-76df559f68-cdr7m   1/1     Running   0          3m51s
myapp-76df559f68-fxjxv   1/1     Running   0          3m59s
myapp-76df559f68-xzrrr   1/1     Running   0          3m58s
#	我額門發現容器名全變了，而且連 rs 都變了


[root@server2 ~]# kubectl get all
NAME                         READY   STATUS    RESTARTS   AGE
pod/demo                     1/1     Running   1          20m
pod/myapp-76df559f68-bjwwx   1/1     Running   0          5m3s
pod/myapp-76df559f68-cdr7m   1/1     Running   0          5m2s
pod/myapp-76df559f68-fxjxv   1/1     Running   0          5m10s
pod/myapp-76df559f68-xzrrr   1/1     Running   0          5m9s

NAME                 TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE
service/kubernetes   ClusterIP   10.96.0.1       <none>        443/TCP   20h
service/myapp        ClusterIP   10.109.116.35   <none>        80/TCP    53m

NAME                    READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/myapp   4/4     4            4           104m

NAME                               DESIRED   CURRENT   READY   AGE
replicaset.apps/myapp-687598b8b4   0         0         0       104m		# 原來的 rs 還在，用於回滾
replicaset.apps/myapp-76df559f68   4         4         4       5m10s	# 創建了新的rs來維護現在這個版本 


# 負載均衡
[root@server2 ~]# kubectl attach demo -it		#連接這個pod

/ # curl 10.109.116.35		# 訪問service的VIP
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
								# 加上這個可以顯示pod ip
/ # curl 10.109.116.35/hostname.html
myapp-76df559f68-bjwwx
/ # curl 10.109.116.35/hostname.html
myapp-76df559f68-cdr7m
/ # curl 10.109.116.35/hostname.html
myapp-76df559f68-fxjxv
/ # curl 10.109.116.35/hostname.html
myapp-76df559f68-cdr7m

# 這就是負載均衡的功能

回滾

[root@server2 ~]# kubectl set image deployments myapp nginx=myapp:v2 --record
deployment.apps/myapp image updated
[root@server2 ~]# kubectl rollout history deployment myapp 		# 查看歷史版本
deployment.apps/myapp 
REVISION  CHANGE-CAUSE
1         <none>
2         kubectl set image deployments myapp nginx=myapp:v1 --record=true
3         kubectl set image deployments myapp nginx=myapp:v2 --record=true
[root@server2 ~]# kubectl attach demo -it

/ # curl 10.109.116.35
Hello MyApp | Version: v2 | <a href="hostname.html">Pod Name</a>
/ # curl 10.109.116.35/hostname.html
myapp-bf4d57f8f-8b82j			# 又是新的pod
/ # curl 10.109.116.35/hostname.html
myapp-bf4d57f8f-svq28

[root@server2 ~]# kubectl rollout history deployment myapp 
deployment.apps/myapp 
REVISION  CHANGE-CAUSE
1         <none>
2         kubectl set image deployments myapp nginx=myapp:v1 --record=true
3         kubectl set image deployments myapp nginx=myapp:v2 --record=true
# 當前有三個版本
[root@server2 ~]# kubectl rollout undo deployment myapp --to-revision=2	  #回退到第二個
deployment.apps/myapp rolled back
[root@server2 ~]# kubectl attach demo -it
Defaulting container name to demo.
Use 'kubectl describe pod/demo -n default' to see all of the containers in this pod.
If you don't see a command prompt, try pressing enter.
/ # curl 10.109.116.35
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>		# 回滾了

通過外部結點訪問service

[root@server2 ~]# kubectl get svc 
NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)   AGE
kubernetes   ClusterIP   10.96.0.1       <none>        443/TCP   21h
myapp        ClusterIP   10.109.116.35   <none>        80/TCP    80m
[root@server2 ~]# kubectl edit svc myapp 
service/myapp edited
[root@server2 ~]# kubectl get svc 
NAME         TYPE        CLUSTER-IP      EXTERNAL-IP   PORT(S)        AGE
kubernetes   ClusterIP   10.96.0.1       <none>        443/TCP        21h
myapp        NodePort    10.109.116.35   <none>        80:31470/TCP   82m

修改svc的類型爲nodeport.

此時又爲我們分配了一個31470端口，端口是隨機分配的，在工作結點上

[root@server4 ~]# netstat -tnlp |grep 31470
tcp        0      0 0.0.0.0:31470           0.0.0.0:*               LISTEN      26106/kube-proxy
[root@server3 ~]# netstat -tnlp |grep 31470
tcp        0      0 0.0.0.0:31470           0.0.0.0:*               LISTEN      26106/kube-proxy

我們就可以通過外部訪問了，這次就不用去訪問service的 VIP，而是直接訪問主機的ip：

[root@rhel7host yum.repos.d]# curl 172.25.254.3:31470
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
[root@rhel7host yum.repos.d]# curl 172.25.254.4:31470
Hello MyApp | Version: v1 | <a href="hostname.html">Pod Name</a>
[root@rhel7host yum.repos.d]# curl 172.25.254.4:31470/hostname.html
myapp-76df559f68-vbclz
[root@rhel7host yum.repos.d]# curl 172.25.254.4:31470/hostname.html
myapp-76df559f68-fwqqw
[root@rhel7host yum.repos.d]# curl 172.25.254.4:31470/hostname.html
myapp-76df559f68-gqz7p

k8s -- pod 的管理

pod運行管理

自主式pod

deployment控制器

pod的擴容縮容：

service微服務

滾動更新

通過外部結點訪問service

.Net 8.0 下的新RPC，IceRPC之試試的新玩法"打洞"

完美替代postman的軟件

Vue mockjs mock.js

關於遊戲付費的一點想法

我通過CKA和CKS啦！

《最新出爐》系列入門篇-Python+Playwright自動化測試-42-強大的可視化追蹤利器Trace Viewer

大數據怎麼學？對大數據開發領域及崗位的詳細解讀，完整理解大數據開發領域技術體系

kubernetes -- 結點調度控制的幾種方式

kubernetes存儲 -- Volumes管理（三）StatefulSet控制器、StatefulSet部署mysql主從集羣

kubernetes存儲 -- Volumes管理（一）emptyDir卷、hostpath卷、NFS卷

kubernetes存儲 -- Volumes管理（二）pv持久卷 +NFS、存儲類。

kubernetes存儲 -- Secret配置管理

https://yachay.unat.edu.pe/blog/index.php?comment_area=format_blog&comment_component=blog&comment_co

linux以太網驅動總結