一 為什么使用控制器

pod控制器

作用：1.pod類型資源刪除，不會(huì)重建
? ? ? ? ? ?2.控制器可以幫助用戶監(jiān)控，并保證節(jié)點(diǎn)上運(yùn)行定義好的pod副本數(shù)
? ? ? ? ? ?3.pod超過或低于用戶期望，控制器會(huì)創(chuàng)建、刪除pod副本數(shù)量

控制器類型：

1. RS控制器:按照用戶期望的副本數(shù)量，創(chuàng)建pod,?用戶寫yaml，定義RS控制器，去定義pod模板，pod按照這個(gè)模板去運(yùn)行
2. deployment控制器
3. DaemonSet

二 詳解rs控制器原理

RS控制器原理：副本數(shù)保障、標(biāo)簽選擇器

2.1 創(chuàng)建RS控制器

[root@k8s-master ~]# cat rs-nginx.yml 
apiVersion: apps/v1
kind: ReplicaSet
metadata:name: nginx-rsnamespace: lxyspec:replicas: 3selector:matchLabels:app: nginxtemplate:metadata:name: nginx-podlabels:app: nginxspec:containers:- name: nginx-containersimage: nginx:1.14.0imagePullPolicy: IfNotPresentports:- name: httpcontainerPort: 80

kubectl create -f rs-nginx.yml 
kubectl -n lxy get rs -owide
kubectl -n lxy get pods -l app=nginx -owide

?

2.2 刪除Pod,查看rs如何保障副本數(shù)?

刪掉一個(gè)pod,但是會(huì)馬上創(chuàng)建一個(gè)

2.3 pod和rs關(guān)系?

kubectl -n lxy describe rs nginx-rs?

2.4 修改RS控制器

1.對(duì)yaml修改副本數(shù)，修改資源配置：kubectl apply -f rs-nginx.yml

2.編輯RS控制器：kubectl -n lxy edit rs nginx-rs? (有些是無法修改)

三 Deploy控制器與彈性擴(kuò)縮容

kubectl scale --help

kubectl -n lxy scale --replicas=X?rs nginx-rs?

root@k8s-master ~]# kubectl -n lxy get pods -owide
NAME             READY   STATUS    RESTARTS   AGE     IP            NODE         NOMINATED NODE   READINESS GATES
nginx-2          1/1     Running   2          5d17h   10.2.20.143   k8s-node13   <none>           <none>
nginx-rs-2zhzn   1/1     Running   0          7h25m   10.2.231.96   k8s-node12   <none>           <none>
nginx-rs-7p64w   1/1     Running   0          7h25m   10.2.20.146   k8s-node13   <none>           <none>
[root@k8s-master ~]# kubectl -n lxy scale --replicas=4 rs nginx-rs 
replicaset.apps/nginx-rs scaled
[root@k8s-master ~]# kubectl -n lxy get pods -owide
NAME             READY   STATUS    RESTARTS   AGE     IP            NODE         NOMINATED NODE   READINESS GATES
nginx-2          1/1     Running   2          5d17h   10.2.20.143   k8s-node13   <none>           <none>
nginx-rs-2zhzn   1/1     Running   0          7h34m   10.2.231.96   k8s-node12   <none>           <none>
nginx-rs-7p64w   1/1     Running   0          7h34m   10.2.20.146   k8s-node13   <none>           <none>
nginx-rs-8jf8p   1/1     Running   0          4s      10.2.20.150   k8s-node13   <none>           <none>
nginx-rs-k9dvr   1/1     Running   0          4s      10.2.20.149   k8s-node13   <none>           <none>
[root@k8s-master ~]# kubectl -n lxy scale --replicas=2 rs nginx-rs 
replicaset.apps/nginx-rs scaled
[root@k8s-master ~]# kubectl -n lxy get pods -owide
NAME             READY   STATUS        RESTARTS   AGE     IP            NODE         NOMINATED NODE   READINESS GATES
nginx-2          1/1     Running       2          5d17h   10.2.20.143   k8s-node13   <none>           <none>
nginx-rs-2zhzn   1/1     Running       0          7h34m   10.2.231.96   k8s-node12   <none>           <none>
nginx-rs-7p64w   1/1     Running       0          7h34m   10.2.20.146   k8s-node13   <none>           <none>
nginx-rs-8jf8p   0/1     Terminating   0          12s     10.2.20.150   k8s-node13   <none>           <none>
nginx-rs-k9dvr   0/1     Terminating   0          12s     10.2.20.149   k8s-node13   <none>           <none>

獲取當(dāng)前rs資源的Yaml:?kubectl -n lxy get rs nginx-rs -oyaml

四 Deploy與rs原理

Deployments | Kubernetes

kubectl -n kube-system get deploy coredns -o yaml

[root@k8s-master ~]# cat deployment.yaml 
apiVersion: apps/v1
kind: Deployment
metadata:name: nginx-deploymentnamespace: lxy
spec:replicas: 2selector:matchLabels:app: nginxtemplate:metadata:labels:app: nginxspec:containers:- name: nginximage: nginx:1.14.2ports:- containerPort: 80resources:limits:cpu: 100mmemory: 200Mirequests:cpu: 100mmemory: 200Mi

[root@k8s-master ~]# kubectl get deployments.apps -owide -n lxy
NAME               READY   UP-TO-DATE   AVAILABLE   AGE    CONTAINERS   IMAGES         SELECTOR
nginx-deployment   2/2     2            2           110s   nginx        nginx:1.14.2   app=nginx
[root@k8s-master ~]# kubectl get rs -n lxy
NAME                          DESIRED   CURRENT   READY   AGE
nginx-deployment-58df99679c   2         2         2       115s
nginx-rs                      2         2         2       8h
[root@k8s-master ~]# kubectl get pods -l app=nginx -n lxy
NAME                                READY   STATUS    RESTARTS   AGE
nginx-deployment-58df99679c-tqxps   1/1     Running   0          119s
nginx-deployment-58df99679c-zhvcj   1/1     Running   0          119s
nginx-rs-2zhzn                      1/1     Running   0          8h
nginx-rs-7p64w                      1/1     Running   0          8h

pod和rs和deployment關(guān)系
kubectl describe pods nginx-deployment-AAA-XX
kubectl describe rs nginx-deployment-AAA?

五 滾動(dòng)更新詳解原理

藍(lán)綠更新：起一個(gè)新的Pod+刪除一個(gè)舊pod,接替就是滾動(dòng)更新

六 更新鏡像版本其他玩法

1.kubectl edit rs資源
2.kubectl ?scale ?--replicas=xxx ? rs ?rs名
3.edit 編輯deployment資源
4.deployment提供了 修改鏡像版本 參數(shù) ? kubectl ?set image

七 版本更新與回滾詳解

因?yàn)閞s控制器還在，數(shù)據(jù)還在?kubectl get rs -owide -w /?kubectl get rs -owide -n lxy

#查看版本是1.14.2
kubectl get deployments.apps -n lxy -owide
#修改版本為1.14.1
kubectl -n lxy set image deployment nginx-deployment nginx=nginx:1.14.1
#這時(shí)候在查看是1.14.1，使用命令回歸后，恢復(fù)成1.14.2
kubectl rollout undo deployment nginx-deployment -n lxy

八 詳解版本記錄號(hào)玩法

1.kubectl create -f last-deploy-nginx.yml --record? ? ----創(chuàng)建的時(shí)候，記錄版本號(hào)

2.查看deploy版本信息

kubectl rollout history deployment ?last-nginx-deployment?

kubectl rollout status ?deployment ?last-nginx-deployment?

kubectl rollout history deployment last-nginx-deployment --revision=2（指定那個(gè)版本的鏡像信息）

3.指定回滾到哪個(gè)版本

kubectl rollout undo ?deployment last-nginx-deployment --to-revision=1