查看deployments
[root@master yaml]# kubectl get deployments
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
nginx-deployment 3 0 0 0 1s
NAME:在集群中的部署名称
DESIRED:显示配置里定义的副本数量,这是应该达到的副本数量
CURRENT:当前正在运行的副本数量
UP-TO-DATE:更新到当前所需状态的副本数量
AVAILABLE:可供使用的副本数量
AEG:显示app存活的时间
通过下面语句可查追踪部署情况
[root@master ~]# kubectl rollout status deployment/nginx-deployment
deployment "nginx-deployment" successfully rolled out
# 这是部署完成的状态
# 未完成的会显示当前部署哪一步了
[root@master ~]# kubectl rollout status deployment/nginx-deployment
Waiting for rollout to finish: 2 out of 3 new replicas have been updated...
deployment "nginx-deployment" successfully rolled out
过一会我们再查看,就全
[root@master ~]# kubectl get deployments
NAME DESIRED CURRENT UP-TO-DATE AVAILABLE AGE
nginx-deployment 3 3 3 3 51s
这里注意如果定义了.spec.minReadySeconds,那么必须经过定义的时间才会达到AVAILABLE 状态
通过下面的命令查看Deployment创建的ReplicaSet(rs)
[root@master ~]# kubectl get rs
NAME DESIRED CURRENT READY AGE
nginx-deployment-6c54bd5869 3 3 3 56m
注意ReplicaSet的名称格式为[DEPLOYMENT-NAME]-[POD-TEMPLATE-HASH-VALUE],后面的hash值是由Deployment自动创建的
查看Pods
[root@master ~]# kubectl get pods --show-labels
NAME READY STATUS RESTARTS AGE LABELSnginx-deployment-6c54bd5869-9brqp 1/1 Running 0 58m app=nginx,pod-template-hash=2710681425
nginx-deployment-6c54bd5869-dkmgh 1/1 Running 0 58m app=nginx,pod-template-hash=2710681425
nginx-deployment-6c54bd5869-vzsht 1/1 Running 0 58m app=nginx,pod-template-hash=2710681425
创建的ReplicaSet 会确保时刻有3个nginx Pods的副本在运行 更新Deployment
假设我们想把nginx从1.7.9更新到1.9.1,有以下3种方式
1. 直接set命令设置变更的部分
$ kubectl set image deployment/nginx-deployment nginx=nginx:1.9.1
deployment "nginx-deployment" image updated
以上命令会自动回滚更改Pods,即停止一定量的老的,新建新的,直到来的终止完,新的启动完
通过describe即可查看所有的细节
[root@master yaml]# kubectl describe deployment/nginx-deployment
Name: nginx-deployment
Namespace: default
CreationTimestamp: Thu, 15 Mar 2018 02:51:06 -0400
Labels: app=nginx
Annotations: deployment.kubernetes.io/revision=2
kubernetes.io/change-cause=kubectl set image deployment/nginx-deployment nginx=nginx:1.9.1
Selector: app=nginx
Replicas: 3 desired | 3 updated | 3 total | 3 available | 0 unavailable
StrategyType: RollingUpdate
MinReadySeconds: 0RollingUpdateStrategy: 25% max unavailable, 25% max surge
Pod Template:
Labels: app=nginx
Containers:
nginx:
Image: nginx:1.9.1
Port: 80/TCP
Environment:
Mounts:
Volumes:
Conditions: Type Status Reason
---- ------ ------
Available True MinimumReplicas
Available Progressing True NewReplicaSetAvailable
OldReplicaSets:
NewReplicaSet: nginx-deployment-5964dfd755 (3/3 replicas created)
Events: Type Reason Age From Message
---- ------ ---- ---- -------
Normal ScalingReplicaSet 2m deployment-controller Scaled up replica set nginx-deployment-5964dfd755 to 1
Normal ScalingReplicaSet 2m deployment-controller Scaled down replica set nginx-deployment-6c54bd5869 to 2
Normal ScalingReplicaSet 2m deployment-controller Scaled up replica set nginx-deployment-5964dfd755 to 2
Normal ScalingReplicaSet 2m deployment-controller Scaled down replica set nginx-deployment-6c54bd5869 to 1
Normal ScalingReplicaSet 2m deployment-controller Scaled up replica set nginx-deployment-5964dfd755 to 3
Normal ScalingReplicaSet 2m deployment-controller Scaled down replica set nginx-deployment-6c54bd5869 to 0
可见image已经变了
另外Events可查看滚动更新的过程
另外上面的说的停止和新建的比例在这里体现RollingUpdateStrategy: 25% max unavailable, 25% max surge,25% max unavailable确保在更新时只有部分会关闭(这里是pod数的25%会关闭)。25% max surge确保创建新的pod也在一定比例上(这里默认也是25%)
2. 通过直接修改线上的配置也可直接修改
kubectl edit deployment/nginx-deployment
会打开一个编辑器,修改指定的部分即可,这里是.spec.template.spec.containers[0].image
3. 修改yaml文件,通过apply重新部署
[root@master yaml]# kubectl apply -f nginx-deployment.yaml
Warning: kubectl apply should be used on resource created by either kubectl create --save-config or kubectl apply
deployment "nginx-deployment" configured
但这里有个警告: 也就是apply方式更新的资源应该是由kubectl create 加--save-config参数创建的 或 由apply创建的 (apply当资源不存在时会创建)
这时我们查看rs,会显示新起了一个rs并将副本扩到3个,旧的rs都缩减为0
[root@master yaml]# kubectl get rs
NAME DESIRED CURRENT READY AGE
nginx-deployment-5964dfd755 3 3 3 21m
nginx-deployment-6c54bd5869 0 0 0 1h 回滚Deployment
有时需要回滚的操作,比如更新错误,手误等一系列问题
比如上面的操作更新到1.9.1时,写错了,写成1.91了
[root@master yaml]# kubectl set image deployment/nginx-deployment nginx=nginx:1.91
deployment "nginx-deployment" image updated
追踪状态
[root@master yaml]# kubectl rollout status deployments nginx-deployment
Waiting for rollout to finish: 1 out of 3 new replicas have been updated...
可见卡住不动了, Ctrl+C终止,查看rs如下
[root@master yaml]# kubectl get rs
NAME DESIRED CURRENT READY AGE
nginx-deployment-5964dfd755 3 3 3 40m
nginx-deployment-5d5cfdbd5f 1 1 0 1m
nginx-deployment-6c54bd5869 0 0 0 2h
新的rs只启动了Pod但没有处于READY状态
查看Pods
[root@master yaml]# kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx-deployment-5964dfd755-8z8b7 1/1 Running 0 27m
nginx-deployment-5964dfd755-bnznj 1/1 Running 0 27m
nginx-deployment-5964dfd755-pt54q 1/1 Running 0 27m
nginx-deployment-5d5cfdbd5f-srdcc 0/1 ImagePullBackOff 0 2m
可发现ImagePullBackOff,实际就是镜像不存在
要修复这个,我们就需要rollback到前一个ok的版本
查看操作历史
[root@master yaml]# kubectl rollout history deployment/nginx-deployment
deployments "nginx-deployment"
REVISION CHANGE-CAUSE
1 kubectl create -f docs/user-guide/nginx-deployment.yaml --record
2 kubectl set image deployment/nginx-deployment nginx=nginx:1.9.1
3 kubectl set image deployment/nginx-deployment nginx=nginx:1.91
要查看每个版本的详细情况,指定--revision
[root@master yaml]# kubectl rollout history deployment/nginx-deployment --revision=2
deployments "nginx-deployment" with revision #2
Pod Template:
Labels: app=nginx pod-template-hash=2710681425
Annotations: kubernetes.io/change-cause=kubectl edit deployment/nginx-deployment
Containers:
nginx:
Image: nginx:1.9.1
Port: 80/TCP
Environment:
Mounts:
Volumes:
接下来进行回滚的操作
不指定版本,默认回滚到上一个版本
[root@master yaml]# kubectl rollout undo deployment/nginx-deployment
deployment "nginx-deployment" rolled back
指定版本,通过--to-revision指定
[root@master yaml]# kubectl rollout undo deployment/nginx-deployment --to-revision=2
deployment "nginx-deployment" rolled back
查看
kubectl describe deployment/nginx-deployment
...............
可看到有DeploymentRollback Reason的事件 扩展Deployment
可通过如下的命令进行扩展
[root@master yaml]# kubectl scale deployment nginx-deployment --replicas=5
deployment "nginx-deployment" scaled
查看Pods
[root@master yaml]# kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx-deployment-5964dfd755-8z8b7 1/1 Running 0 41m
nginx-deployment-5964dfd755-bhm2s 1/1 Running 0 1m
nginx-deployment-5964dfd755-bnznj 1/1 Running 0 41m
nginx-deployment-5964dfd755-cftfj 1/1 Running 0 6s
nginx-deployment-5964dfd755-pt54q 1/1 Running 0 41m
可见已扩展到5个
使用autoscale还可设置自动水平扩展(hpa),可根据机器负载之类的信息自动扩展或缩减,这个后面细讲
$ kubectl autoscale deployment nginx-deployment --min=10 --max=15 --cpu-percent=80
deployment "nginx-deployment" autoscaled
暂停和恢复Deployment
有时需要修改多个部分,而不是上面的只修改image,这样的话每次改完都自动部署,显然不好,通过pause即可暂停Deployment,更改完了,通过resume即可恢复部署
暂停
[root@master yaml]# kubectl rollout pause deployment/nginx-deployment
deployment "nginx-deployment" paused
修改
[root@master yaml]# kubectl set image deploy/nginx-deployment nginx=nginx:1.7.9
deployment "nginx-deployment" image updated
查看Pods
[root@master yaml]# kubectl get pods
NAME READY STATUS RESTARTS AGE
nginx-deployment-5964dfd755-8z8b7 1/1 Running 0 57m
nginx-deployment-5964dfd755-bhm2s 1/1 Running 0 17m
nginx-deployment-5964dfd755-bnznj 1/1 Running 0 57m
nginx-deployment-5964dfd755-cftfj 1/1 Running 0 16m
nginx-deployment-5964dfd755-pt54q 1/1 Running 0 57m
注意后面的AGE还是之前的Pod,这里就不会自动更新了
恢复
[root@master yaml]# kubectl rollout resume deploy/nginx-deployment
deployment "nginx-deployment" resumed
这时再查看Pods
[root@master yaml]# kubectl get podsNAME READY STATUS RESTARTS AGEnginx-deployment-6c54bd5869-htjxz 1/1 Running 0 25s
nginx-deployment-6c54bd5869-lj288 1/1 Running 0 30s
nginx-deployment-6c54bd5869-nt8lt 1/1 Running 0 30s
nginx-deployment-6c54bd5869-svqz6 1/1 Running 0 29s
nginx-deployment-6c54bd5869-zq8tl 1/1 Running 0 25s
可见已经更新部署了
内部Deployment部分大概就讲完了,下面把nginx服务暴露到外面 删除Deployment
[root@master yaml]# kubectl delete -f nginx-deployment.yaml
deployment "nginx-deployment" deleted
部署service
服务的暴露需要Service,它是Pod的抽象代理(具体机制见这里)。见nginx-service.yaml
apiVersion: v1
kind: Service
metadata:
name: nginx-service
spec:
type: NodePort
sessionAffinity: ClientIP
selector:
app: nginx
ports:
- port: 80
nodePort: 30080