一、deployment无状态负载

1、deployment无状态负载

一种特殊的pod

优势：
1、支持副本自动维护
2、支持滚动更新

应用场景: 频繁更新的业务

deployment创建流程：
deployment -----> RS(副本集) -----> POD

标签选择器：
标签，就是个key:value对的数据
通过标签在RS和POD间建立对应关系

二、创建deployment

1、创建deployment

apiVersion: apps/v1
kind: Deployment
metadata:name: test1-nginx
spec:replicas: 4selector:matchLabels:app: nginx								// rs标签 template:metadata:labels:app: nginx						// pod标签 spec:containers:- name: test1-nginximage: nginx:1.16imagePullPolicy: IfNotPresent

// 查看无状态负载
[root@k8s-master deployTest]# kubectl get deploy
NAME          READY   UP-TO-DATE   AVAILABLE   AGE
test1-nginx   4/4     4            4           52s// 查看rs副本集
[root@k8s-master deployTest]# kubectl get rs 
NAME                     DESIRED   CURRENT   READY   AGE
test1-nginx-5d858b7fc5   4         4         4       101s[root@k8s-master deployTest]# kubectl get pod 
NAME                           READY   STATUS    RESTARTS   AGE
test1-nginx-5d858b7fc5-74mps   1/1     Running   0          2m43s
test1-nginx-5d858b7fc5-kg8f7   1/1     Running   0          2m43s
test1-nginx-5d858b7fc5-ldx8s   1/1     Running   0          2m43s
test1-nginx-5d858b7fc5-x76z2   1/1     Running   0          2m43s// 查看pod的标签 
[root@k8s-master deployTest]# kubectl get pod --show-labels 
NAME                           READY   STATUS    RESTARTS   AGE     LABELS
test1-nginx-5d858b7fc5-74mps   1/1     Running   0          5m28s   app=nginx,pod-template-hash=5d858b7fc5
test1-nginx-5d858b7fc5-kg8f7   1/1     Running   0          5m28s   app=nginx,pod-template-hash=5d858b7fc5
test1-nginx-5d858b7fc5-ldx8s   1/1     Running   0          5m28s   app=nginx,pod-template-hash=5d858b7fc5
test1-nginx-5d858b7fc5-x76z2   1/1     Running   0          5m28s   app=nginx,pod-template-hash=5d858b7fc5

2、验证副本维护

[root@k8s-master deployTest]# kubectl get pod 
NAME                           READY   STATUS    RESTARTS   AGE
test1-nginx-5d858b7fc5-74mps   1/1     Running   0          7m39s
test1-nginx-5d858b7fc5-kg8f7   1/1     Running   0          7m39s
test1-nginx-5d858b7fc5-ldx8s   1/1     Running   0          7m39s
test1-nginx-5d858b7fc5-x76z2   1/1     Running   0          7m39s// 删除任意pod
[root@k8s-master deployTest]# kubectl delete pod test1-nginx-5d858b7fc5-ldx8s
pod "test1-nginx-5d858b7fc5-ldx8s" deleted// 再次查看pod
[root@k8s-master deployTest]# kubectl get pod 
NAME                           READY   STATUS    RESTARTS   AGE
test1-nginx-5d858b7fc5-74mps   1/1     Running   0          7m59s
test1-nginx-5d858b7fc5-kg8f7   1/1     Running   0          7m59s
test1-nginx-5d858b7fc5-wj6g6   1/1     Running   0          5s
test1-nginx-5d858b7fc5-x76z2   1/1     Running   0          7m59s

三、deployment滚动更新

1、创建pod

apiVersion: apps/v1
kind: Deployment
metadata:name: test2-nginx
spec:replicas: 6selector:matchLabels:app: nginx2strategy:type: RollingUpdate					// 更新策略为滚动更新rollingUpdate:maxSurge: 2							// 每次更新的数量，可以是绝对数字、百分比数字maxUnavailable: 3				// 最大无效数量，可以是绝对数字、百分比数字template:metadata:labels:app: nginx2spec:containers:- name: test2-nginximage: nginx:1.16imagePullPolicy: IfNotPresent

[root@k8s-master deployTest]# kubectl get rs
NAME                     DESIRED   CURRENT   READY   AGE
test2-nginx-569d77d6cb   6         6         6       85s[root@k8s-master deployTest]# kubectl get pod 
NAME                           READY   STATUS    RESTARTS   AGE
test2-nginx-569d77d6cb-4xmpw   1/1     Running   0          88s
test2-nginx-569d77d6cb-57xpk   1/1     Running   0          88s
test2-nginx-569d77d6cb-5bs4n   1/1     Running   0          88s
test2-nginx-569d77d6cb-9nsqb   1/1     Running   0          88s
test2-nginx-569d77d6cb-qstqr   1/1     Running   0          88s
test2-nginx-569d77d6cb-tqbkn   1/1     Running   0          88s

2、测试滚动更新流程

2.1、修改镜像版本、或者副本数

2.2、执行更新

[root@k8s-master deployTest]# kubectl apply -f test2-nginx.yaml 

2.3、查看更新过程

[root@k8s-master deployTest]# kubectl get pod
NAME                           READY   STATUS              RESTARTS   AGE
test2-nginx-569d77d6cb-46tjl   0/1     Terminating         0          6m48s
test2-nginx-569d77d6cb-88qwt   0/1     Terminating         0          6m46s
test2-nginx-569d77d6cb-8s8r9   1/1     Running             0          6m48s
test2-nginx-569d77d6cb-f7pdw   1/1     Running             0          6m48s
test2-nginx-569d77d6cb-jgtcx   0/1     Terminating         0          6m48s
test2-nginx-569d77d6cb-ttm7s   0/1     Terminating         0          6m45s
test2-nginx-569d77d6cb-vh7xh   1/1     Terminating         0          6m45s
test2-nginx-57c7d85bfd-5k87b   1/1     Running             0          4s
test2-nginx-57c7d85bfd-64vdn   1/1     Running             0          4s
test2-nginx-57c7d85bfd-9h7wv   0/1     ContainerCreating   0          2s
test2-nginx-57c7d85bfd-c9bbg   0/1     ContainerCreating   0          2s
test2-nginx-57c7d85bfd-df8nx   1/1     Running             0          4s
test2-nginx-57c7d85bfd-k7db6   0/1     ContainerCreating   0          2s
test2-nginx-57c7d85bfd-q5x2f   1/1     Running             0          4s
test2-nginx-57c7d85bfd-sbbkw   1/1     Running             0          4s
test2-nginx-57c7d85bfd-t8f5z   0/1     ContainerCreating   0          1s
test2-nginx-57c7d85bfd-x58dd   0/1     ContainerCreating   0          2s

[root@k8s-master deployTest]# kubectl describe deploy test2-nginx 
Name:                   test2-nginx
Namespace:              default
CreationTimestamp:      Thu, 25 Jul 2024 16:34:04 +0800
Labels:                 <none>
Annotations:            deployment.kubernetes.io/revision: 4
Selector:               app=nginx2
Replicas:               10 desired | 10 updated | 10 total | 10 available | 0 unavailable
StrategyType:           RollingUpdate
MinReadySeconds:        0
RollingUpdateStrategy:  3 max unavailable, 2 max surge
Pod Template:Labels:  app=nginx2Containers:test2-nginx:Image:        nginx:1.18Port:         <none>Host Port:    <none>Environment:  <none>Mounts:       <none>Volumes:        <none>
Conditions:Type           Status  Reason----           ------  ------Available      True    MinimumReplicasAvailableProgressing    True    NewReplicaSetAvailable
OldReplicaSets:  test2-nginx-569d77d6cb (0/0 replicas created)
NewReplicaSet:   test2-nginx-57c7d85bfd (10/10 replicas created)
Events:Type    Reason             Age                    From                   Message----    ------             ----                   ----                   -------Normal  ScalingReplicaSet  13m                    deployment-controller  Scaled up replica set test2-nginx-569d77d6cb to 6Normal  ScalingReplicaSet  9m51s                  deployment-controller  Scaled up replica set test2-nginx-57c7d85bfd to 2Normal  ScalingReplicaSet  9m51s                  deployment-controller  Scaled down replica set test2-nginx-569d77d6cb to 3 from 6Normal  ScalingReplicaSet  9m51s                  deployment-controller  Scaled up replica set test2-nginx-57c7d85bfd to 5 from 2Normal  ScalingReplicaSet  9m49s                  deployment-controller  Scaled down replica set test2-nginx-569d77d6cb to 2 from 3Normal  ScalingReplicaSet  9m49s                  deployment-controller  Scaled up replica set test2-nginx-57c7d85bfd to 6 from 5Normal  ScalingReplicaSet  9m48s                  deployment-controller  Scaled down replica set test2-nginx-569d77d6cb to 1 from 2Normal  ScalingReplicaSet  9m48s                  deployment-controller  Scaled down replica set test2-nginx-569d77d6cb to 0 from 1Normal  ScalingReplicaSet  9m1s                   deployment-controller  Scaled up replica set test2-nginx-57c7d85bfd to 10 from 6Normal  ScalingReplicaSet  2m17s (x18 over 9m1s)  deployment-controller  (combined from similar events): Scaled up replica set test2-nginx-57c7d85bfd to 5 from 2

2.4、查看更新历史

[root@k8s-master deployTest]# kubectl rollout history deploy test2-nginx 
deployment.apps/test2-nginx 
REVISION  CHANGE-CAUSE
2         <none>
3         <none>

2.5、版本回退

[root@k8s-master deployTest]# kubectl rollout undo deployment test2-nginx --to-revision=2 
deployment.apps/test2-nginx rolled back

2.6、暂停更新

[root@k8s-master deployTest]# kubectl rollout pause deployment test2-nginx