1、Deployment作用

控制Pod，使Pod拥有多副本，自愈，扩缩容等能力

2、deployment的冗余能力

创建一个deployment的pod用delete删除不了，下面案例两种创建pod的不通

[root@master ~]# kubectl run nginx --image=nginx
pod/nginx created
[root@master ~]# kubectl create deployment myginx01 --image=nginx
deployment.apps/myginx01 created[root@master ~]# kubectl delete  pod nginx
pod "nginx" deleted[root@master ~]# kubectl delete pod myginx01-5c9d6dbf77-k75d5
pod "myginx01-5c9d6dbf77-k75d5" deleted
[root@master ~]# kubectl get pod 
NAME                        READY   STATUS    RESTARTS   AGE
myginx01-5c9d6dbf77-k8f8x   1/1     Running   0          2m45s

#也可以在开一个窗口看一下效果

[root@master ~]# watch  -n 1  kubectl get pod

只有把delopment删除以后才可以删除pod

[root@master ~]# kubectl delete deploy myginx01
deployment.apps "myginx01" deleted
[root@master ~]# kubectl get pod
No resources found in default namespace.

3、deployment的多副本部署

案例走起：

[root@master ~]# kubectl create deploy mynginx --image=nginx --replicas=3
deployment.apps/mynginx created[root@master ~]# kubectl get pod -owide
NAME                       READY   STATUS    RESTARTS   AGE   IP                NODE     NOMINATED NODE   READINESS GATES
mynginx-5b686ccd46-4w2nm   1/1     Running   0          36s   192.168.196.146   node01   <none>           <none>
mynginx-5b686ccd46-cxtjn   1/1     Running   0          36s   192.168.196.144   node01   <none>           <none>
mynginx-5b686ccd46-j5xpq   1/1     Running   0          36s   192.168.196.145   node01   <none>           <none>
[root@master ~]# kubectl get deploy
NAME      READY   UP-TO-DATE   AVAILABLE   AGE
mynginx   3/3     3            3           92s

也可以在bashboard上部署

用yaml部署

先创建一个yaml

apiVersion: apps/v1
kind: Deployment
metadata:labels:app: my-depname: my-dep
spec:replicas: 3selector:matchLabels:app: my-deptemplate:metadata:labels:app: my-depspec:containers:- image: nginxname: nginx

[root@master ~]# kubectl apply -f pod.yaml 
deployment.apps/my-dep created
[root@master ~]# kubectl get deploy
NAME      READY   UP-TO-DATE   AVAILABLE   AGE
my-dep    2/3     3            2           30s
mynginx   5/5     5            5           16m
[root@master ~]# kubectl get deploy
NAME      READY   UP-TO-DATE   AVAILABLE   AGE
my-dep    3/3     3            3           35s
mynginx   5/5     5            5           16m
[root@master ~]#

4、deployment的扩缩容

kubectl scale --replicas=5 deployment/my-dep

kubectl edit deploy my-dep

案例走起：

[root@master ~]# kubectl get deploy
NAME     READY   UP-TO-DATE   AVAILABLE   AGE
my-dep   3/3     3            3           7m17s
[root@master ~]# kubectl scale deploy/my-dep --replicas=5
deployment.apps/my-dep scaled
[root@master ~]# kubectl get deploy
NAME     READY   UP-TO-DATE   AVAILABLE   AGE
my-dep   5/5     5            5           8m10s
[root@master ~]# kubectl scale deploy/my-dep --replicas=2
deployment.apps/my-dep scaled
[root@master ~]# kubectl get deploy
NAME     READY   UP-TO-DATE   AVAILABLE   AGE
my-dep   2/2     2            2           8m42s
[root@master ~]# kubectl edit deploy my-dep
deployment.apps/my-dep edited
[root@master ~]# kubectl get deploy
NAME     READY   UP-TO-DATE   AVAILABLE   AGE
my-dep   2/3     3            2           11m

5、deployment的自愈能力

案例走起：

在node01节点上停止一个容器看效果

[root@node01 ~]# docker ps |grep my-dep-5b7868d854-dgrt4
14744aac665a   nginx                                               "/docker-entrypoint.…"   13 minut8s_nginx_my-dep-5b7868d854-dgrt4_default_bc8be424-2226-44f3-8dc5-49b08d1ef3fe_0
96beef3e2dba   registry.aliyuncs.com/google_containers/pause:3.2   "/pause"                 13 minut8s_POD_my-dep-5b7868d854-dgrt4_default_bc8be424-2226-44f3-8dc5-49b08d1ef3fe_0
[root@node01 ~]# docker ps |grep my-dep-5b7868d854-dgrt4
14744aac665a   nginx                                               "/docker-entrypoint.…"   14 minutdgrt4_default_bc8be424-2226-44f3-8dc5-49b08d1ef3fe_0
96beef3e2dba   registry.aliyuncs.com/google_containers/pause:3.2   "/pause"                 14 minutrt4_default_bc8be424-2226-44f3-8dc5-49b08d1ef3fe_0
[root@node01 ~]# docker stop 14744aac665a
14744aac665a
[root@node01 ~]#

发现node01节点的容器重启了一次

[root@master ~]# kubectl get pod
NAME                      READY   STATUS    RESTARTS   AGE
my-dep-5b7868d854-dgrt4   1/1     Running   1          16m
my-dep-5b7868d854-lq6mz   1/1     Running   0          27m
my-dep-5b7868d854-pgp9n   1/1     Running   0          27m

现在我们把node01服务器关机看效果

[root@master ~]# kubectl get pod -w
NAME                      READY   STATUS    RESTARTS   AGE
my-dep-5b7868d854-dgrt4   1/1     Running   1          20m
my-dep-5b7868d854-lq6mz   1/1     Running   0          31m
my-dep-5b7868d854-pgp9n   1/1     Running   0          31m
my-dep-5b7868d854-dgrt4   1/1     Terminating   1          25m
my-dep-5b7868d854-6qzt6   0/1     Pending       0          0s
my-dep-5b7868d854-6qzt6   0/1     Pending       0          0s
my-dep-5b7868d854-6qzt6   0/1     ContainerCreating   0          0s
my-dep-5b7868d854-6qzt6   0/1     ContainerCreating   0          1s
my-dep-5b7868d854-6qzt6   1/1     Running             0          2s
[root@master ~]# kubectl get pod -owide
NAME                      READY   STATUS        RESTARTS   AGE     IP                NODE     NOMINATED NODE   READINESS GATES
my-dep-5b7868d854-6qzt6   1/1     Running       0          2m18s   192.168.140.81    node02   <none>           <none>
my-dep-5b7868d854-dgrt4   1/1     Terminating   1          27m     192.168.196.154   node01   <none>           <none>
my-dep-5b7868d854-lq6mz   1/1     Running       0          38m     192.168.140.80    node02   <none>           <none>
my-dep-5b7868d854-pgp9n   1/1     Running       0          38m     192.168.140.79    node02   <none>           <none>

6、滚动更新

以yaml的方式查看pod

[root@master ~]# kubectl get deploy my-dep -o yaml
...spec:containers:- image: nginximagePullPolicy: Alwaysname: nginx
...

现在我们要变更镜像的版本

[root@master ~]# kubectl set image deploy/my-dep nginx=nginx:1.16.1  --record
deployment.apps/my-dep image updated

查看效果：

[root@master ~]# kubectl get pod -w
NAME                      READY   STATUS              RESTARTS   AGE
my-dep-5b7868d854-6qzt6   1/1     Running             0          10m
my-dep-5b7868d854-lq6mz   1/1     Running             0          46m
my-dep-5b7868d854-pgp9n   1/1     Running             0          46m
my-dep-6b48cbf4f9-x25jn   0/1     ContainerCreating   0          23s
my-dep-6b48cbf4f9-x25jn   1/1     Running             0          50s
my-dep-5b7868d854-6qzt6   1/1     Terminating         0          10m
my-dep-6b48cbf4f9-gfhnf   0/1     Pending             0          0s
my-dep-6b48cbf4f9-gfhnf   0/1     Pending             0          0s
my-dep-6b48cbf4f9-gfhnf   0/1     ContainerCreating   0          0s
my-dep-5b7868d854-6qzt6   1/1     Terminating         0          10m
my-dep-6b48cbf4f9-gfhnf   0/1     ContainerCreating   0          1s
my-dep-5b7868d854-6qzt6   0/1     Terminating         0          10m
my-dep-6b48cbf4f9-gfhnf   1/1     Running             0          2s
my-dep-5b7868d854-lq6mz   1/1     Terminating         0          46m
my-dep-6b48cbf4f9-ztzzw   0/1     Pending             0          0s
my-dep-6b48cbf4f9-ztzzw   0/1     Pending             0          0s
my-dep-6b48cbf4f9-ztzzw   0/1     ContainerCreating   0          0s
my-dep-5b7868d854-lq6mz   1/1     Terminating         0          46m
my-dep-6b48cbf4f9-ztzzw   0/1     ContainerCreating   0          1s
my-dep-5b7868d854-lq6mz   0/1     Terminating         0          46m
my-dep-5b7868d854-6qzt6   0/1     Terminating         0          10m
my-dep-5b7868d854-6qzt6   0/1     Terminating         0          10m
my-dep-5b7868d854-lq6mz   0/1     Terminating         0          46m
my-dep-5b7868d854-lq6mz   0/1     Terminating         0          46m
my-dep-6b48cbf4f9-ztzzw   1/1     Running             0          17s
my-dep-5b7868d854-pgp9n   1/1     Terminating         0          46m
my-dep-5b7868d854-pgp9n   1/1     Terminating         0          46m
my-dep-5b7868d854-pgp9n   0/1     Terminating         0          46m
my-dep-5b7868d854-pgp9n   0/1     Terminating         0          47m
my-dep-5b7868d854-pgp9n   0/1     Terminating         0          47m
[root@master ~]# kubectl get pod -o wide
NAME                      READY   STATUS    RESTARTS   AGE     IP                NODE     NOMINATED NODE   READINESS GATES
my-dep-6b48cbf4f9-gfhnf   1/1     Running   0          2m41s   192.168.196.158   node01   <none>           <none>
my-dep-6b48cbf4f9-x25jn   1/1     Running   0          3m31s   192.168.196.157   node01   <none>           <none>
my-dep-6b48cbf4f9-ztzzw   1/1     Running   0          2m39s   192.168.196.159   node01   <none>           <none>
[root@master ~]#

[root@master ~]# kubectl get deploy -o yaml...spec:containers:- image: nginx:1.16.1imagePullPolicy: Alwaysname: nginxresources: {}terminationMessagePath: /dev/termination-logterminationMessagePolicy: File

7、版本回退

查看历史命令

[root@master ~]# kubectl rollout history deployment/my-dep
deployment.apps/my-dep 
REVISION  CHANGE-CAUSE
1         <none>
2         kubectl set image deploy/my-dep nginx=nginx:1.16.1 --record=true

设置回退到1的时候：

[root@master ~]# kubectl rollout undo deploy/my-dep --to-revision=1
deployment.apps/my-dep rolled back

参考一下镜像版本：

[root@master ~]# kubectl get deploy/my-dep -o yaml |grep image{"apiVersion":"apps/v1","kind":"Deployment","metadata":{"annotations":{},"labels":{"app":"my-dep"},"name":"my-dep","namespace":"default"},"spec":{"replicas":3,"selector":{"matchLabels":{"app":"my-dep"}},"template":{"metadata":{"labels":{"app":"my-dep"}},"spec":{"containers":[{"image":"nginx","name":"nginx"}]}}}}f:imagePullPolicy: {}f:image: {}- image: nginximagePullPolicy: Always

Kubernetes-核心概念-其他工作负载

Deployment: 无状态应用部署，比如微服务，提供多副本等功能

StatefulSet:有状态应用部署，比如redis，提供稳定的存储、网络等功能

DaemonSet:守护型应用部署，比如日志收集组件，在每个机器都运行一份

Job/CronJob:定时任务部署，比如垃圾清理组件，可以在指定时间运行