一起来学k8s 02.pod label

Pod LabelLabelLabel相当于熟悉的“标签”，给某个资源对象定义一个Label，就相当于给它打了一个标签，随后可以通过Label Selector（标签选择器）查询和筛选拥有某些Label的资源对象。Labels 介绍以Pod为例，Label定义在metadata中：apiVersion: v1kind: Podmetadata:name: myweblab...

隔壁小翔

1078人浏览 · 2019-07-01 20:56:35

隔壁小翔 · 2019-07-01 20:56:35 发布

Pod Label

环境

192.168.48.101 master01
192.168.48.201 node01
192.168.48.202 node02

Label

Label相当于熟悉的“标签”，给某个资源对象定义一个Label，就相当于给它打了一个标签，随后可以通过Label Selector（标签选择器）查询和筛选拥有某些Label的资源对象。

Labels 介绍

以Pod为例，Label定义在metadata中：

apiVersion: v1
kind: Pod
metadata:
  name: myweb
  labels:
    app: myweb

RC和Service在spec中定义Selector与Pod进行关联

apiVersion: v1
kind: ReplicationController
metadata:
  name: myweb
spec:
  replicas: 1
  selector:
    app: myweb
  template:
  …………

Deployment、ReplicaSet、DaemonSet和Job则可以在Selector中使用基于集合的筛选条件

selector:
  matchLabels:
    app: myweb
  matchExpressions:
    - {key: tier, operator: In, values: [frontend]}
    - {key: environment, operator: NotIn, values: [dev]}

运行pod例子

demo-pod

vim demo-pod.yaml

apiVersion: v1
kind: Pod
metadata:
  name: demo-pod
  namespace: default
  labels:
    app: myapp
    type: pod
spec:
  containers:
  - name: myapp
    image: ikubernetes/myapp:v1
    ports:
    - name: http
      containerPort: 80

kubectl apply -f  demo-pod.yaml

demo-deploy

vim demo-deploy.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: demo-deploy
  namespace: default
  labels:
    app: myapp
    type: deploy
spec:
  replicas: 2
  selector:
    matchLabels:
      app: myapp
      type: deploy
  template:
    metadata:
      name: myapp-pod
      labels:
        app: myapp
        type: deploy
    spec:
      containers:
      - name: myapp
        image: ikubernetes/myapp:v1
        ports:
        - name: http
          containerPort: 80

kubectl apply -f demo-deploy.yaml

demo-replicaset

vim  demo-replicaset.yaml

apiVersion: apps/v1
kind: ReplicaSet
metadata:
  name: demo-replicaset
  namespace: default
  labels:
    app: myapp
    type: replicaset
spec:
  replicas: 2
  selector:
    matchLabels:
      app: myapp
      type: replicaset
  template:
    metadata:
      name: myapp-pod
      labels:
        app: myapp
        type: replicaset
    spec:
      containers:
      - name: myapp
        image: ikubernetes/myapp:v1
        ports:
        - name: http
          containerPort: 80

kubectl apply -f demo-replicaset.yaml

Labels 查看

查看所有pods标签

[root@master01 ~]# kubectl get pods --show-labels
NAME                           READY   STATUS    RESTARTS   AGE   LABELS
demo-deploy-8675c97685-vhncn   1/1     Running   1          31h   app=myapp,pod-template-hash=8675c97685,type=deploy
demo-deploy-8675c97685-w7md2   1/1     Running   1          31h   app=myapp,pod-template-hash=8675c97685,type=deploy
demo-pod                       2/2     Running   4          31h   app=myapp,type=pod
demo-replicaset-fpbs6          1/1     Running   0          6s    app=myapp,type=replicaset
demo-replicaset-qk9t9          1/1     Running   0          6s    app=myapp,type=replicaset

查看拥有app标签的pods

[root@master01 ~]# kubectl get pods -l app --show-labels
NAME                           READY   STATUS    RESTARTS   AGE   LABELS
demo-deploy-8675c97685-vhncn   1/1     Running   1          31h   app=myapp,pod-template-hash=8675c97685,type=deploy
demo-deploy-8675c97685-w7md2   1/1     Running   1          31h   app=myapp,pod-template-hash=8675c97685,type=deploy
demo-pod                       2/2     Running   4          31h   app=myapp,type=pod
demo-replicaset-fpbs6          1/1     Running   0          80s   app=myapp,type=replicaset
demo-replicaset-qk9t9          1/1     Running   0          80s   app=myapp,type=replicaset

打标签

[root@master01 ~]# kubectl label pod demo-pod  release=canary
pod/demo-pod labeled

[root@master01 ~]# kubectl get pods -l release  --show-labels
NAME       READY   STATUS    RESTARTS   AGE   LABELS
demo-pod   2/2     Running   4          31h   app=myapp,release=canary,type=pod

修改标签

[root@master01 ~]# kubectl label pod demo-pod release=stable --overwrite
pod/demo-pod labeled

[root@master01 ~]# kubectl get pods -l release  --show-labels
NAME       READY   STATUS    RESTARTS   AGE   LABELS
demo-pod   2/2     Running   4          31h   app=myapp,release=stable,type=pod

可以利用in来查询标签

[root@master01~]# kubectl get pod -l "type in (pod,deploy)" --show-labels
NAME                           READY   STATUS    RESTARTS   AGE   LABELS
demo-deploy-8675c97685-vhncn   1/1     Running   1          31h   app=myapp,pod-template-hash=8675c97685,type=deploy
demo-deploy-8675c97685-w7md2   1/1     Running   1          31h   app=myapp,pod-template-hash=8675c97685,type=deploy
demo-pod                       2/2     Running   4          31h   app=myapp,release=stable,type=pod

[root@master01 ~]# kubectl get pod -l "type notin (pod,deploy)" --show-labels
NAME                    READY   STATUS    RESTARTS   AGE     LABELS
demo-replicaset-fpbs6   1/1     Running   0          9m21s   app=myapp,type=replicaset
demo-replicaset-qk9t9   1/1     Running   0          9m21s   app=myapp,type=replicaset

给node打标签

[root@master01 ~]# kubectl get nodes --show-labels
NAME     STATUS   ROLES    AGE   VERSION   LABELS
master   Ready    master   41h   v1.15.0   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=master,kubernetes.io/os=linux,node-role.kubernetes.io/master=
node01   Ready    <none>   41h   v1.15.0   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=node01,kubernetes.io/os=linux
node02   Ready    <none>   41h   v1.15.0   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.io/arch=amd64,kubernetes.io/hostname=node02,kubernetes.io/os=linux

[root@master01 ~]# kubectl label nodes node01 disk=ssd
node/node01 labeled

[root@master01 ~]# kubectl get nodes --show-labels -l disk
NAME     STATUS   ROLES    AGE   VERSION   LABELS
node01   Ready    <none>   41h   v1.15.0   beta.kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,disk=ssd,kubernetes.io/arch=amd64,kubernetes.io/hostname=node01,kubernetes.io/os=linux

定义node节点选择器

vim demo-pod-ssd.yaml

apiVersion: v1
kind: Pod
metadata:
  name: demo-pod-ssd
  namespace: default
  labels:
    app: myapp
    type: pod-ssd
spec:
  containers:
  - name: myapp
    image: ikubernetes/myapp:v1
    ports:
    - name: http
      containerPort: 80
  nodeSelector:
    disk: ssd

创建并查看 pod在node01上

kubectl apply -f demo-pod-ssd.yaml

[root@master01 ~]# kubectl get pod -o wide
NAME                           READY   STATUS    RESTARTS   AGE   IP           NODE     NOMINATED NODE   READINESS GATES
demo-deploy-8675c97685-vhncn   1/1     Running   1          31h   10.244.2.6   node02   <none>           <none>
demo-deploy-8675c97685-w7md2   1/1     Running   1          31h   10.244.1.6   node01   <none>           <none>
demo-pod                       2/2     Running   4          31h   10.244.2.7   node02   <none>           <none>
demo-pod-ssd                   1/1     Running   0          47s   10.244.1.9   node01   <none>           <none>
demo-replicaset-fpbs6          1/1     Running   0          17m   10.244.1.8   node01   <none>           <none>
demo-replicaset-qk9t9          1/1     Running   0          17m   10.244.2.9   node02   <none>           <none>

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