|NO.Z.00153|——————————|CloudNative|——|KuberNetes&服務釋出.V04|-------------------------------------------------------|label&selector.v04|selector查詢|

阿新 • • 發佈：2022-03-30

一、selector的查詢語法

### --- 通過一個條件匹配label過濾符合條件的pod
~~~     通過一個條件來匹配：假設我們有這麼多Pod   
~~~     假設我們需要檢視metrics-scraper和dashboard這個Pod，我們如何過濾

[root@k8s-master01 ~]# kubectl get po -A --show-labels
NAMESPACE              NAME                                         READY   STATUS             RESTARTS   AGE     LABELS
default                busybox                                      1/1     Running            0          19m     app=busybox
default                nginx-sfqkz                                  1/1     Running            0          4h24m   app=nginx,controller-revision-hash=6495b6bbfc,pod-template-generation=4
default                nginx-ts5x4                                  1/1     Running            0          4h32m   app=nginx,controller-revision-hash=6495b6bbfc,pod-template-generation=4
default                nginx-v245j                                  1/1     Running            0          4h31m   app=nginx,controller-revision-hash=6495b6bbfc,pod-template-generation=4
kube-public            busybox                                      0/1     CrashLoopBackOff   7          13m     app=busybox2,run=busybox
kube-system            calico-kube-controllers-5f6d4b864b-6clrl     1/1     Running            0          9d      k8s-app=calico-kube-controllers,pod-template-hash=5f6d4b864b
kube-system            calico-node-6hbtl                            1/1     Running            0          9d      controller-revision-hash=dc4b7567d,k8s-app=calico-node,pod-template-generation=1
kube-system            calico-node-77c2f                            1/1     Running            3          9d      controller-revision-hash=dc4b7567d,k8s-app=calico-node,pod-template-generation=1
kube-system            calico-node-hrqpt                            1/1     Running            1          9d      controller-revision-hash=dc4b7567d,k8s-app=calico-node,pod-template-generation=1
kube-system            calico-node-trkhw                            1/1     Running            0          9d      controller-revision-hash=dc4b7567d,k8s-app=calico-node,pod-template-generation=1
kube-system            calico-node-z4gkj                            1/1     Running            0          9d      controller-revision-hash=dc4b7567d,k8s-app=calico-node,pod-template-generation=1
kube-system            coredns-867d46bfc6-sk5dp                     1/1     Running            0          9d      k8s-app=kube-dns,pod-template-hash=867d46bfc6
kube-system            metrics-server-595f65d8d5-slhtd              1/1     Running            1          9d      k8s-app=metrics-server,pod-template-hash=595f65d8d5
kubernetes-dashboard   dashboard-metrics-scraper-7645f69d8c-7dd2b   1/1     Running            0          9d      k8s-app=dashboard-metrics-scraper,pod-template-hash=7645f69d8c
kubernetes-dashboard   kubernetes-dashboard-78cb679857-mqccg        1/1     Running            13         9d      k8s-app=kubernetes-dashboard,pod-template-hash=78cb679857

### --- 過濾符合條件的pod

[root@k8s-master01 ~]# kubectl get po -A -l 'k8s-app in(metrics-server, kubernetes-dashboard)'      //-l：就是過濾同時符合兩個條件的，就是k8s-app等於後面括號裡的引數
NAMESPACE              NAME                                    READY   STATUS    RESTARTS   AGE
kube-system            metrics-server-595f65d8d5-slhtd         1/1     Running   1          9d
kubernetes-dashboard   kubernetes-dashboard-78cb679857-mqccg   1/1     Running   13         9d

二、通過不符合條件的labelpod過濾出來

### --- 給nginx再加上一個label

[root@k8s-master01 ~]# kubectl get po 
NAME          READY   STATUS    RESTARTS   AGE
nginx-sfqkz   1/1     Running   0          4h29m
 [root@k8s-master01 ~]# kubectl label po nginx-sfqkz version=v1
pod/nginx-sfqkz labeled

### --- 檢視所有容器的label

[root@k8s-master01 ~]# kubectl get po --show-labels
NAME          READY   STATUS    RESTARTS   AGE     LABELS
nginx-sfqkz   1/1     Running   0          4h30m   app=nginx,controller-revision-hash=6495b6bbfc,pod-template-generation=4,version=v1
nginx-ts5x4   1/1     Running   0          4h37m   app=nginx,controller-revision-hash=6495b6bbfc,pod-template-generation=4
nginx-v245j   1/1     Running   0          4h37m   app=nginx,controller-revision-hash=6495b6bbfc,pod-template-generation=4

### --- 檢視version不等於1，而是等於nginx的label對應的pod
~~~     可以檢視到2個
 
[root@k8s-master01 ~]# kubectl get po -l version!=v1,app=nginx          
NAME          READY   STATUS    RESTARTS   AGE
nginx-ts5x4   1/1     Running   0          4h39m
nginx-v245j   1/1     Running   0          4h38m

三、把APP等於nginx和busybox的label符合條件的pod過濾出來

### --- 把APP等於nginx和busybox的過濾出來且不想啟用version等於v1的

[root@k8s-master01 ~]# kubectl get po -A -l 'app in (busybox, nginx)'       
NAMESPACE   NAME          READY   STATUS    RESTARTS   AGE
default     busybox       1/1     Running   0          27m
default     nginx-sfqkz   1/1     Running   0          4h32m
default     nginx-ts5x4   1/1     Running   0          4h40m
default     nginx-v245j   1/1     Running   0          4h39m

### --- 但是不想啟用version等於v1的
~~~     label：是對一些資源進行分組的，
~~~     selector：是把一些符合標籤的，符合我們規律的，符合查詢條件的過濾出來。
 
[root@k8s-master01 ~]# kubectl get po -A -l version!=v1,'app in (busybox, nginx)'       //可以檢視到少了一個
NAMESPACE   NAME          READY   STATUS    RESTARTS   AGE
default     busybox       1/1     Running   0          28m
default     nginx-ts5x4   1/1     Running   0          4h42m
default     nginx-v245j   1/1     Running   0          4h41m

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Walter Savage Landor:strove with none,for none was worth my strife.Nature I loved and, next to Nature, Art:I warm'd both hands before the fire of life.It sinks, and I am ready to depart ——W.S.Landor

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