|NO.Z.00151|——————————|CloudNative|——|KuberNetes&服務釋出.V02|-------------------------------------------------------|label&selector.v02|label定位pod|
阿新 • • 發佈：2022-03-30
[CloudNative：KuberNetes&服務釋出.V02] [Applications.KuberNetes] [|DevOps|k8s|服務釋出|Label&Selector|]
一、Label和selector
### --- 通過label來劃分宿主機部署pod ### --- 假如實驗環境是5個節點 [root@k8s-master01 ~]# kubectl get node -owide NAME STATUS ROLES AGE VERSION INTERNAL-IP EXTERNAL-IP OS-IMAGE KERNEL-VERSION CONTAINER-RUNTIME k8s-master01 Ready <none> 10d v1.20.0 192.168.1.11 <none> CentOS Linux 7 (Core) 4.19.12-1.el7.elrepo.x86_64 docker://19.3.15 k8s-master02 Ready <none> 10d v1.20.0 192.168.1.12 <none> CentOS Linux 7 (Core) 4.19.12-1.el7.elrepo.x86_64 docker://19.3.15 k8s-master03 Ready <none> 10d v1.20.0 192.168.1.13 <none> CentOS Linux 7 (Core) 4.19.12-1.el7.elrepo.x86_64 docker://19.3.15 k8s-node01 NotReady <none> 10d v1.20.0 192.168.1.14 <none> CentOS Linux 7 (Core) 4.19.12-1.el7.elrepo.x86_64 docker://19.3.15 k8s-node02 NotReady <none> 10d v1.20.0 192.168.1.15 <none> CentOS Linux 7 (Core) 4.19.12-1.el7.elrepo.x86_64 docker://19.3.15
### --- 假設k8s-node02是7網段的，給它打個標籤：新增一個label ~~~ 比如我們公司和銀行業務往來，銀行為我們拉了一個專線， ~~~ 且這個專線不是所有伺服器都可以使用的， ~~~ 銀行那邊可能只設置了你7網段的IP才可以訪問該專線。 ~~~ 我們需要把呼叫銀行API的這個容器部署在7網段的這個容器上， ~~~ 所以我們可以使用label給一批node節點搭上一個label標籤， ~~~ 這個label就說明它是subnet7的，這樣我們就可以使用nodeSelector部署到我們節點上面 [root@k8s-master01 ~]# kubectl label node k8s-node02 region=subnet7 node/k8s-node02 labeled
### --- 使用node節點把它過濾出來
~~~ 過濾出來之後通過nodeSelector去部署它的容器了
[root@k8s-master01 ~]# kubectl get node -l region=subnet7
NAME STATUS ROLES AGE VERSION
k8s-node02 NotReady <none> 10d v1.20.0 ### --- 還可以對其它資源進行label區分 [root@k8s-master01 ~]# kubectl get po --show-labels NAME READY STATUS RESTARTS AGE LABELS nginx-sfqkz 1/1 Running 0 3h57m app=nginx,controller-revision-hash=6495b6bbfc,pod-template-generation=4 nginx-ts5x4 1/1 Running 0 4h4m app=nginx,controller-revision-hash=6495b6bbfc,pod-template-generation=4 nginx-v245j 1/1 Running 0 4h4m app=nginx,controller-revision-hash=6495b6bbfc,pod-template-generation=4
### --- 看所有namespace下的容器
~~~ 給pod新增一個label
~~~ 這個label只是臨時加的，下次更新的時候被替換掉，
~~~ 因為它的Deployment並沒有這個labeled，
~~~ 所以說不要去更改這個label的標籤，
~~~ 若是想要更改的話，需要使用deployment或者高階資源進行更改，
~~~ 但是更改的話也不可以直接去更改，只能起一個新的，把新的pod改個名，
~~~ 然後把label標籤打上；打上之後部署上去。部署完成之後再把這service指過來。
~~~ service指過來之後再把舊的刪除掉。[root@k8s-master01 ~]# kubectl get po -A --show-labels
NAMESPACE NAME READY STATUS RESTARTS AGE LABELS
default nginx-sfqkz 1/1 Running 0 3h57m app=nginx,controller-revision-hash=6495b6bbfc,pod-template-generation=4
default nginx-ts5x4 1/1 Running 0 4h5m app=nginx,controller-revision-hash=6495b6bbfc,pod-template-generation=4
default nginx-v245j 1/1 Running 0 4h4m app=nginx,controller-revision-hash=6495b6bbfc,pod-template-generation=4
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 ### --- 在這個namespace下的pod新增標籤。
[root@k8s-master01 ~]# kubectl get po --show-labels
NAME READY STATUS RESTARTS AGE LABELS
busybox 1/1 Running 0 91s <none>
nginx-sfqkz 1/1 Running 0 4h7m app=nginx,controller-revision-hash=6495b6bbfc,pod-template-generation=4
nginx-ts5x4 1/1 Running 0 4h15m app=nginx,controller-revision-hash=6495b6bbfc,pod-template-generation=4
nginx-v245j 1/1 Running 0 4h14m app=nginx,controller-revision-hash=6495b6bbfc,pod-template-generation=4### --- 為busybox打上標籤
[root@k8s-master01 ~]# kubectl label po busybox app=busybox
pod/busybox labeled
[root@k8s-master01 ~]# kubectl get po --show-labels
NAME READY STATUS RESTARTS AGE LABELS
busybox 1/1 Running 0 2m17s app=busybox //可以檢視到這個label已經新增上了
nginx-sfqkz 1/1 Running 0 4h8m app=nginx,controller-revision-hash=6495b6bbfc,pod-template-generation=4
nginx-ts5x4 1/1 Running 0 4h15m app=nginx,controller-revision-hash=6495b6bbfc,pod-template-generation=4
nginx-v245j 1/1 Running 0 4h15m app=nginx,controller-revision-hash=6495b6bbfc,pod-template-generation=4### --- 通過select過濾一下符合我們標籤的；檢視namespace下符合busybox標籤的容器有哪些
[root@k8s-master01 ~]# kubectl get po -A -l app=busybox
NAMESPACE NAME READY STATUS RESTARTS AGE
default busybox 1/1 Running 0 4m5s // 目前環境下只有這一個### --- 再啟動一個busybox
[root@k8s-master01 ~]# kubectl run busybox --image=busybox:1.28 -n kube-public //-n指定名稱空間
pod/busybox created
[root@k8s-master01 ~]# kubectl get po -n kube-public
NAME READY STATUS RESTARTS AGE
busybox 0/1 Completed 2 35s // 這個不用去管，因為它沒有前臺啟動的程序，所以就顯示completed狀態### --- 給它也打上標籤
[root@k8s-master01 ~]# kubectl label po busybox app=busybox -n kube-public
pod/busybox labeled ### --- 再次過濾一下
[root@k8s-master01 ~]# kubectl get po -A -l app=busybox
NAMESPACE NAME READY STATUS RESTARTS AGE
default busybox 1/1 Running 0 7m39s
kube-public busybox 0/1 CrashLoopBackOff 4 2m16s### --- 檢視service的標籤
~~~ 在建立資源的時候一定要給這個資源新增上標籤，
~~~ 這樣我們才能區分這個service是幹嘛用的，它的角色是什麼
~~~ 或者對它進行分組，更好的去管理
[root@k8s-master01 ~]# kubectl get svc -A --show-labels
NAMESPACE NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE LABELS
default kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 10d component=apiserver,provider=kubernetes
default nginx ClusterIP None <none> 80/TCP 8h app=nginx===============================END===============================
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