Kubectl管理工具

1、常用指令如下

运行应用程序

[root@manager ~]# kubectl run hello-world --replicas=3 --labels="app=example" --image=nginx:1.10 --port=80

[root@manager ~]# kubectl get pods --selector="app=example"
NAME                          READY     STATUS              RESTARTS   AGE
hello-world-cc85d4fb6-btsvz   0/1       ContainerCreating   0          33s
hello-world-cc85d4fb6-mtg75   0/1       ContainerCreating   0          33s
hello-world-cc85d4fb6-r57vx   0/1       ContainerCreating   0          33s
[root@manager ~]# 

[root@manager ~]# kubectl describe pod hello-world-cc85d4fb6-btsvz
Name:           hello-world-cc85d4fb6-btsvz
Namespace:      default
Node:           192.168.10.221/192.168.10.221
Start Time:     Fri, 02 Feb 2018 10:13:01 +0800
Labels:         app=example
                pod-template-hash=774180962
Annotations:    kubernetes.io/created-by={"kind":"SerializedReference","apiVersion":"v1","reference":{"kind":"ReplicaSet","namespace":"default","name":"hello-world-cc85d4fb6","uid":"98254448-07be-11e8-af8c-5254002bf2...
Status:         Pending
IP:             
Created By:     ReplicaSet/hello-world-cc85d4fb6
Controlled By:  ReplicaSet/hello-world-cc85d4fb6
Containers:
  hello-world:
    Container ID:   
    Image:          nginx:1.10
    Image ID:       
    Port:           80/TCP
    State:          Waiting
      Reason:       ContainerCreating
    Ready:          False
    Restart Count:  0
    Environment:    <none>
    Mounts:         <none>
Conditions:
  Type           Status
  Initialized    True 
  Ready          False 
  PodScheduled   True 
Volumes:         <none>
QoS Class:       BestEffort
Node-Selectors:  <none>
Tolerations:     <none>
Events:
  Type    Reason     Age   From                     Message
  ----    ------     ----  ----                     -------
  Normal  Scheduled  1m    default-scheduler        Successfully assigned hello-world-cc85d4fb6-btsvz to 192.168.10.221
  Normal  Pulling    1m    kubelet, 192.168.10.221  pulling image "nginx:1.10"
  Normal  Pulled     6s    kubelet, 192.168.10.221  Successfully pulled image "nginx:1.10"

查看pod所属标签
[root@manager ~]# kubectl get pods --show-labels
NAME                          READY     STATUS    RESTARTS   AGE       LABELS
busybox                       1/1       Running   47         1d        <none>
busybox2                      1/1       Running   5          1d        <none>
hello-world-cc85d4fb6-btsvz   1/1       Running   0          2m        app=example,pod-template-hash=774180962
hello-world-cc85d4fb6-mtg75   1/1       Running   0          2m        app=example,pod-template-hash=774180962
hello-world-cc85d4fb6-r57vx   1/1       Running   0          2m        app=example,pod-template-hash=774180962

根据标签查看pod

[root@manager ~]# kubectl get pods -l app=example -o wide
NAME READY STATUS RESTARTS AGE IP NODE
hello-world-cc85d4fb6-btsvz 1/1 Running 0 3m 10.0.91.5 192.168.10.221
hello-world-cc85d4fb6-mtg75 1/1 Running 0 3m 10.0.71.8 192.168.10.222
hello-world-cc85d4fb6-r57vx 1/1 Running 0 3m 10.0.91.6 192.168.10.221

显示有关deployment信息

[root@manager ~]# kubectl get deployments hello-world
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
hello-world 3 3 3 3 3m
[root@manager ~]#
[root@manager ~]# kubectl describe deployments hello-world
Name: hello-world
Namespace: default
CreationTimestamp: Fri, 02 Feb 2018 10:13:01 +0800
Labels: app=example
Annotations: deployment.kubernetes.io/revision=1
Selector: app=example
Replicas: 3 desired | 3 updated | 3 total | 3 available | 0 unavailable
StrategyType: RollingUpdate
MinReadySeconds: 0
RollingUpdateStrategy: 1 max unavailable, 1 max surge
Pod Template:
Labels: app=example
Containers:
hello-world:
Image: nginx:1.10
Port: 80/TCP
Environment: <none>
Mounts: <none>
Volumes: <none>
Conditions:
Type Status Reason
---- ------ ------
Available True MinimumReplicasAvailable
OldReplicaSets: <none>
NewReplicaSet: hello-world-cc85d4fb6 (3/3 replicas created)
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal ScalingReplicaSet 4m deployment-controller Scaled up replica set hello-world-cc85d4fb6 to 3

显示有关rs信息

[root@manager ~]# kubectl get replicasets
NAME DESIRED CURRENT READY AGE
hello-world-cc85d4fb6 3 3 3 4m
[root@manager ~]#
[root@manager ~]# kubectl describe replicasets
Name: hello-world-cc85d4fb6
Namespace: default
Selector: app=example,pod-template-hash=774180962
Labels: app=example
pod-template-hash=774180962
Annotations: deployment.kubernetes.io/desired-replicas=3
deployment.kubernetes.io/max-replicas=4
deployment.kubernetes.io/revision=1
Controlled By: Deployment/hello-world
Replicas: 3 current / 3 desired
Pods Status: 3 Running / 0 Waiting / 0 Succeeded / 0 Failed
Pod Template:
Labels: app=example
pod-template-hash=774180962
Containers:
hello-world:
Image: nginx:1.10
Port: 80/TCP
Environment: <none>
Mounts: <none>
Volumes: <none>
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
Normal SuccessfulCreate 4m replicaset-controller Created pod: hello-world-cc85d4fb6-btsvz
Normal SuccessfulCreate 4m replicaset-controller Created pod: hello-world-cc85d4fb6-mtg75
Normal SuccessfulCreate 4m replicaset-controller Created pod: hello-world-cc85d4fb6-r57vx

扩容pod数量

[root@manager ~]# kubectl scale deployment --replicas=5 hello-world
deployment "hello-world" scaled

[root@manager ~]#
[root@manager ~]# kubectl get pods --selector="app=example" -o wide
NAME READY STATUS RESTARTS AGE IP NODE
hello-world-cc85d4fb6-btsvz 1/1 Running 0 5m 10.0.91.5 192.168.10.221
hello-world-cc85d4fb6-mppx2 1/1 Running 0 17s 10.0.71.9 192.168.10.222
hello-world-cc85d4fb6-mtg75 1/1 Running 0 5m 10.0.71.8 192.168.10.222
hello-world-cc85d4fb6-r57vx 1/1 Running 0 5m 10.0.91.6 192.168.10.221
hello-world-cc85d4fb6-xgv4z 1/1 Running 0 17s 10.0.91.7 192.168.10.221

创建一个Service对象暴露Deployment（在88端口负载TCP流量）
[root@manager ~]# kubectl expose deployment hello-world --port=88 --type=NodePort --target-port=80 --name=example-service
service "example-service" exposed
[root@manager ~]# 
[root@manager ~]# kubectl describe services example-service
Name:                     example-service
Namespace:                default
Labels:                   app=example
Annotations:              <none>
Selector:                 app=example
Type:                     NodePort
IP:                       10.10.10.11
Port:                     <unset>  88/TCP
TargetPort:               80/TCP
NodePort:                 <unset>  31916/TCP
Endpoints:                10.0.71.8:80,10.0.71.9:80,10.0.91.5:80 + 2 more...
Session Affinity:         None
External Traffic Policy:  Cluster
Events:                   <none>

使用节点IP和节点端口访问应用程序
[root@node1 ~]# curl 10.10.10.11:88
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
    body {
         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>

清理应用

kubectl delete services example-service

kubectl delete deployment hello-world

[root@manager ~]# kubectl get all
NAME          READY     STATUS    RESTARTS   AGE
po/busybox    1/1       Running   47         1d
po/busybox2   1/1       Running   5          1d

NAME             TYPE        CLUSTER-IP   EXTERNAL-IP   PORT(S)   AGE
svc/kubernetes   ClusterIP   10.10.10.1   <none>        443/TCP   2d

yaml配置文件管理资源

配置文件说明：
定义配置时，指定最新稳定版API（当前为v1）；
配置文件应该存储在集群之外的版本控制仓库中。如果需要，可以快速回滚配置、重新创建和恢复；
应该使用YAML格式编写配置文件，而不是JSON。尽管这些格式都可以使用，但YAML对用户更加友好；
可以将相关对象组合成单个文件，通常会更容易管理；
不要没必要的指定默认值，简单和最小配置减少错误；
在注释中说明一个对象描述更好维护。

[root@manager ~]# 
[root@manager ~]# cat nginx-deployment.yaml 
apiVersion: apps/v1beta2
kind: Deployment
metadata:
  name: nginx-deployment
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.10
        ports:
        - containerPort: 80


[root@manager ~]# kubectl create -f nginx-deployment.yaml 
deployment "nginx-deployment" created

[root@manager ~]# cat nginx-service.yaml
apiVersion: v1
kind: Service
metadata:
name: nginx-service
labels:
app: nginx
spec:
ports:
- port: 88
targetPort: 80
selector:
app: nginx

[root@manager ~]#
[root@manager ~]# kubectl create -f nginx-service.yaml
service "nginx-service" created
[root@manager ~]#
[root@manager ~]#
[root@manager ~]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.10.10.1 <none> 443/TCP 2d
nginx-service ClusterIP 10.10.10.243 <none> 88/TCP 9s

[root@manager ~]# kubectl describe services nginx-service
Name: nginx-service
Namespace: default
Labels: app=nginx
Annotations: <none>
Selector: app=nginx
Type: ClusterIP
IP: 10.10.10.243
Port: <unset> 88/TCP
TargetPort: 80/TCP
Endpoints: 10.0.71.8:80,10.0.71.9:80,10.0.91.5:80
Session Affinity: None
Events: <none>