controller（控制器）
1、什么是controller
（1）在集群上管理和运行容器的对象
2、Pod和controller关系
（1）Pod是通过Controller实现应用的运维，比如伸缩、滚动升级等
（2）Pod和Controller之间通过Pod上打label标签和controller上的selector建立关系
3、Deployment控制器的应用场景
（1）部署无状态的应用（web服务，微服务）
（2）管理Pod和ReplicaSet(副本创建)
（3）部署，滚动升级
4、yaml文件字段说明
[root@k8smaster ~]# kubectl create deployment web --image=nginx --dry-run -o yaml > web.yaml
W1214 15:55:56.144418 28060 helpers.go:535] --dry-run is deprecated and can be replaced with --dry-run=client.
[root@k8smaster ~]# cat web.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
creationTimestamp: null
labels:
app: web
name: web
spec:
replicas: 1
selector:
matchLabels:
app: web
strategy: {}
template:
metadata:
creationTimestamp: null
labels:
app: web
spec:
containers:
- image: nginx
name: nginx
resources: {}
status: {}
#通过yaml文件进行部署
[root@k8smaster ~]# kubectl apply -f web.yaml
deployment.apps/web created
#查看部署的pod
[root@k8smaster ~]# kubectl get pod
NAME READY STATUS RESTARTS AGE
web-5dcb957ccc-2xfmz 1/1 Running 0 14s
#对外发布（暴露端口）
[root@k8smaster ~]# kubectl expose deployment web --port=80 --type=NodePort --target-port=80 --name=web1 -o yaml > web1.yaml
[root@k8smaster ~]# cat web1.yaml
apiVersion: v1
kind: Service
metadata:
creationTimestamp: "2021-12-14T08:11:03Z"
labels:
app: web
managedFields:
- apiVersion: v1
fieldsType: FieldsV1
fieldsV1:
f:metadata:
f:labels:
.: {}
f:app: {}
f:spec:
f:externalTrafficPolicy: {}
f:ports:
.: {}
k:{"port":80,"protocol":"TCP"}:
.: {}
f:port: {}
f:protocol: {}
f:targetPort: {}
f:selector:
.: {}
f:app: {}
f:sessionAffinity: {}
f:type: {}
manager: kubectl
operation: Update
time: "2021-12-14T08:11:03Z"
name: web1
namespace: default
resourceVersion: "462761"
selfLink: /api/v1/namespaces/default/services/web1
uid: 69d9eeb0-2ec3-4599-ad2b-3088acd3646b
spec:
clusterIP: 10.101.16.206
externalTrafficPolicy: Cluster
ports:
- nodePort: 30385
port: 80
protocol: TCP
targetPort: 80
selector:
app: web
sessionAffinity: None
type: NodePort
status:
loadBalancer: {}
[root@k8smaster ~]# kubectl apply -f web1.yaml
#查看svc
[root@k8smaster ~]# kubectl get svc
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
kubernetes ClusterIP 10.96.0.1 <none> 443/TCP 2d5h
web1 NodePort 10.101.16.206 <none> 80:30385/TCP 49s
5、Deployment控制器部署应用
6、升级回滚和弹性伸缩
#修改yaml文件，把replicas副本数修改为2，把nginx的版本设置为1.14
[root@k8smaster ~]# cat web.yaml
apiVersion: apps/v1
kind: Deployment
metadata:
creationTimestamp: null
labels:
app: web
name: web
spec:
replicas: 2
selector:
matchLabels:
app: web
strategy: {}
template:
metadata:
creationTimestamp: null
labels:
app: web
spec:
containers:
- image: nginx:1.14
name: nginx
resources: {}
status: {}
[root@k8smaster ~]# kubectl apply -f web.yaml
deployment.apps/web created
[root@k8smaster ~]# kubectl get pod
NAME READY STATUS RESTARTS AGE
web-65b7447c7-779jw 0/1 ContainerCreating 0 10s
web-65b7447c7-j9wv9 0/1 ContainerCreating 0 10s
#升级命令，升级过程中服务不中断
[root@k8smaster ~]# kubectl set image deployment web nginx=nginx:1.15
deployment.apps/web image updated
#查看是否升级成功
[root@k8smaster ~]# kubectl rollout status deployment web
deployment "web" successfully rolled out
#查看历史版本
[root@k8smaster ~]# kubectl rollout history deployment web
deployment.apps/web
REVISION CHANGE-CAUSE
1 <none>
2 <none>
#回滚到上一个版本
[root@k8smaster ~]# kubectl rollout undo deployment web
deployment.apps/web rolled back
#回滚到指定版本
[root@k8smaster ~]# kubectl rollout undo deployment web --to-revision=2
deployment.apps/web rolled back
#弹性伸缩
[root@k8smaster ~]# kubectl scale deployment web --replicas=10
deployment.apps/web scaled
