K8s（六）Deployment资源

发布时间：2024年01月19日

????????Deployment是Kubernetes中的一个重要组件，用于管理应用程序的部署和更新。它提供了一种声明性的方式来定义应用程序的期望状态，并确保集群中的Pod按照这个状态进行部署和维护。简化了应用程序的部署和更新流程，并提供了健康检查、自动扩缩容、历史版本回滚等功能。

相当于Deployment可以来管理ReplicaSet，ReplicaSet是Deployment底下的一个子功能。

????????Deployment可以管理多个rs，进行更新时，可以同时具有多个rs，但同时只使用一个rs。支持版本回滚，并可以支持多种更新策略

yaml文件编写

#Deployment yaml文件编写
#查看帮助
kubectl explain Deployment
apiVersion   <string>
kind <string>
metadata     <Object>
spec <Object>
status       <Object>
#spec内的功能包含replicaSet控制器的功能
kubectl explain Deployment.spec 
minReadySeconds      <integer>           #最小就绪时间，比如要升级就给它设一个值，默认为0
paused       <boolean>    #新pod是否要暂停
progressDeadlineSeconds      <integer> #
replicas     <integer> #pod副本数
revisionHistoryLimit <integer> #历史版本数量限制,默认为10
selector     <Object> -required- #筛选器
strategy     <Object> #更新策略
template     <Object> -required- #pod模板

kubectl explain Deployment.spec.strategy
rollingUpdate        <Object> #滚动更新
type <string>                 #类型，支持下面这两种
Possible enum values:
     - `"Recreate"` Kill all existing pods before creating new ones. #创建之前删除所有老的
     - `"RollingUpdate"` Replace the old ReplicaSets by new one using rolling
     update i.e gradually scale down the old ReplicaSets and scale up the new
     one. #根据更新策略进行更新

kubectl explain Deployment.spec.strategy.rollingUpdate
maxSurge     <string> #更新过程中最多的，比如4个里25%就是最多能同时存在5个
maxUnavailable       <string> #几个不可用的副本数，默认为25%，比如4个里25%最多只能有一个不可用
#可用整形或百分比，如果出现小数，maxSurge向上取整，maxUnavailable向下取整
#且这两个值不能同时为0，默认都为25%%

kubectl explain Deployment.spec.template
metadata     <Object>
spec <Object>

#创建一个yaml文件
cat > dp.yaml << EOF
apiVersion: apps/v1
kind: Deployment
metadata: 
   name: dp-test
   namespace: default
   labels:
     app: tomcat
spec:
#   minReadySeconds: 10 #等待十秒后开始，默认为0秒
#   paused: False #不暂停
#   progressDeadlineSeconds: 600 #最大可等待时间，默认为600秒
   replicas: 3 #副本数，默认为1
   revisionHistoryLimit: 5 #历史版本数，默认为10
   selector: #筛选条件
     matchLabels:
         app: test     #找app=test标签的pod
   template: 
     metadata:
       name: demo
       labels:     
         app: test
     spec: 
         containers:
            - name: dp1
              image: docker.io/library/nginx
              imagePullPolicy: IfNotPresent
              ports:
                - containerPort: 80
EOF
kubectl apply -f dp.yaml
#查看
kubectl get deploy #可用比例、达到预期的副本数、当前可用副本数
NAME      READY   UP-TO-DATE   AVAILABLE   AGE
dp-test   3/3     3            3           69s 
kubectl get rs #定义的期望副本数、正在运行的副本数、就绪的副本数
NAME               DESIRED   CURRENT   READY   AGE
dp-test-648cf4f5   3         3         3       114s
kubectl get pods
NAME                     READY   STATUS    RESTARTS   AGE
dp-test-648cf4f5-hbhmx   1/1     Running   0          2m7s
dp-test-648cf4f5-x9gb4   1/1     Running   0          2m7s
dp-test-648cf4f5-znktp   1/1     Running   0          2m7s

扩容与缩容

#修改dp.yaml
...
replicas: 5 #副本数，默认为1
...
kubectl apply -f dp.yaml
#再查看，已经变成五个了
kubectl get deploy
NAME      READY   UP-TO-DATE   AVAILABLE   AGE
dp-test   5/5     5            5           13m
kubectl get pods
NAME                     READY   STATUS    RESTARTS   AGE
dp-test-648cf4f5-b82kv   1/1     Running   0          3m29s
dp-test-648cf4f5-dssv7   1/1     Running   0          3m29s
dp-test-648cf4f5-hbhmx   1/1     Running   0          13m
dp-test-648cf4f5-x9gb4   1/1     Running   0          13m
dp-test-648cf4f5-znktp   1/1     Running   0          13m
#修改dp.yaml
...
replicas: 2 #副本数，默认为1
...
kubectl apply -f dp.yaml
#查看，删除的时候是随机删除的
kubectl get deploy
NAME      READY   UP-TO-DATE   AVAILABLE   AGE
dp-test   2/2     2            2           14m

滚动更新与自定义策略

#当前状态
curl 10.10.179.43:80
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="<http://nginx.org/>">nginx.org</a>.<br/>
Commercial support is available at
<a href="<http://nginx.com/>">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>
#修改yaml文件，修改镜像
...
   replicas: 4 #副本数，默认为1
...
              image: docker.io/library/tomcat
...
kubectl apply -f dp.yaml
#查看————滚动更新的策略默认为 先创建新的，后删除老的，25%
kubectl get pods -w
NAME                     READY   STATUS    RESTARTS   AGE
dp-test-648cf4f5-b82kv   1/1     Running   0          80m
dp-test-648cf4f5-znktp   1/1     Running   0          90m
dp-test-6b98994689-v7d9w   0/1     Pending   0          0s
dp-test-6b98994689-v7d9w   0/1     Pending   0          0s
dp-test-6b98994689-v7d9w   0/1     ContainerCreating   0          0s
dp-test-6b98994689-v7d9w   0/1     ContainerCreating   0          1s
dp-test-6b98994689-v7d9w   1/1     Running             0          1s
dp-test-648cf4f5-znktp     1/1     Terminating         0          90m
dp-test-6b98994689-fzfv6   0/1     Pending             0          0s
dp-test-6b98994689-fzfv6   0/1     Pending             0          0s
dp-test-6b98994689-fzfv6   0/1     ContainerCreating   0          0s
dp-test-648cf4f5-znktp     1/1     Terminating         0          90m
dp-test-6b98994689-fzfv6   0/1     ContainerCreating   0          1s
dp-test-648cf4f5-znktp     0/1     Terminating         0          90m
dp-test-648cf4f5-znktp     0/1     Terminating         0          90m
dp-test-648cf4f5-znktp     0/1     Terminating         0          90m
dp-test-6b98994689-fzfv6   1/1     Running             0          2s
dp-test-648cf4f5-b82kv     1/1     Terminating         0          80m
dp-test-648cf4f5-b82kv     1/1     Terminating         0          80m
dp-test-648cf4f5-b82kv     0/1     Terminating         0          80m
dp-test-648cf4f5-b82kv     0/1     Terminating         0          80m
dp-test-648cf4f5-b82kv     0/1     Terminating         0          80m
#新的rs接管了，老的rs废弃
kubectl get rs
NAME                 DESIRED   CURRENT   READY   AGE
dp-test-648cf4f5     0         0         0       92m
dp-test-6b98994689   2         2         2       88s
#当前状态
curl 10.10.234.66:8080
<!doctype html><html lang="en"><head><title>HTTP Status 404 – Not Found</title><style type="text/css">body {font-family:Tahoma,Arial,sans-serif;} h1, h2, h3, b {color:white;background-color:#525D76;} h1 {font-size:22px;} h2 {font-size:16px;} h3 {font-size:14px;} p {font-size:12px;} a {color:black;} .line {height:1px;background-color:#525D76;border:none;}</style></head><body><h1>HTTP Status 404 – Not Found</h1><hr class="line" /><p><b>Type</b> Status Report</p><p><b>Description</b> The origin server did not find a current representation for the target resource or is not willing to disclose that one exi

#回滚版本
#查看历史版本
kubectl rollout history deployment #两个历史版本
deployment.apps/dp-test
REVISION  CHANGE-CAUSE
1         <none> #对应nginx镜像
2         <none> #对应tomcat镜像
#进行回滚
kubectl rollout undo deployment.apps/dp-test --to-revision=1
#查看rs，发现老的rs又被使用了
kubectl get rs
NAME                 DESIRED   CURRENT   READY   AGE
dp-test-648cf4f5     2         2         2       99m
dp-test-6b98994689   0         0         0       8m22s
#查看网页状态
curl 10.10.179.46:80
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="<http://nginx.org/>">nginx.org</a>.<br/>
Commercial support is available at
<a href="<http://nginx.com/>">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>

#自定义滚动更新策略
#帮助
kubectl explain Deployment.spec.strategy
rollingUpdate        <Object> #滚动更新
type <string>                 #类型，支持下面这两种，即Recreate与RollingUpate两种
Possible enum values:
     - `"Recreate"` Kill all existing pods before creating new ones. #创建之前删除所有老的
     - `"RollingUpdate"` Replace the old ReplicaSets by new one using rolling
     update i.e gradually scale down the old ReplicaSets and scale up the new
     one. #根据更新策略进行更新
kubectl explain Deployment.spec.strategy.rollingUpdate
maxSurge     <string> #更新过程中最多的，比如4个里25%就是最多能同时存在5个
maxUnavailable       <string> #几个不可用的副本数，默认为25%，比如4个里25%最多只能有一个不可用
#可用整形或百分比，如果出现小数，maxSurge向上取整，maxUnavailable向下取整
#且这两个值不能同时为0，默认都为25%

#使用ollingUpdate模式
#一个一个删
maxUnavailable: 0 #不能少于目标副本数，不能有存在不可用的副本
maxSurge: 1 #顶多多一个
#maxUnavailable越小，更新越稳妥
#maxSurge越大，更新速度越快
#修改yaml文件
...
   replicas: 4 #副本数，默认为1
   strategy:
     rollingUpdate:
        maxUnavailable: 1
        maxSurge: 1
...
kubectl apply -f dp.yaml
kubectl get pods -w #rollingUpdate模式下先创建，后删除
NAME                       READY   STATUS    RESTARTS   AGE
dp-test-6b98994689-7p4qf   1/1     Running   0          26s
dp-test-6b98994689-fg79g   1/1     Running   0          28s
dp-test-6b98994689-gjwpg   1/1     Running   0          28s
dp-test-6b98994689-tmwwj   1/1     Running   0          26s

#使用recreate模式
#修改yaml文件
...
    strategy:
      type: Recreate
...
     image: docker.io/library/nginx #镜像改回来
...
kubectl apply -f dp.yaml
#可以看到是先进行删除，后进行创建，在生产环境中大部分情况下都不会这么操作
kubectl delete -f dp.yaml

使用Deployment进行蓝绿部署

蓝绿部署（Blue-Green Deployment）是一种在应用程序部署过程中实现零停机和无缝切换的策略。它通过同时维护两个完全独立且相同配置的生产环境（蓝色环境和绿色环境），使得在切换新版本应用程序时不会中断用户访问。

与滚动更新不同的是蓝绿部署是同时存在两个环境，然后通过流量切换来切换环境，而滚动更新从始至终只使用了一个环境

#创建蓝色和绿色的命名空间
kubectl create ns blue-green
#创建绿色与蓝色环境的yaml
cat > green.yaml << EOF
apiVersion: apps/v1
kind: Deployment
metadata: 
  name: green
  namespace: blue-green
spec:
  replicas: 2
  selector:
    matchLabels:
      color: green
  template:
    metadata:
      labels:
        color: green
    spec:
      containers:
        - name: test1
          image: docker.io/library/nginx
          imagePullPolicy: IfNotPresent
          ports:
            - containerPort: 80
EOF
kubectl apply -f green.yaml
kubectl get pods -n blue-green --show-labels -owide
NAME                     READY   STATUS    RESTARTS   AGE   IP             NODE           NOMINATED NODE   READINESS GATES   LABELS
green-748cc6748f-76jq6   1/1     Running   0          67s   10.10.179.52   ws-k8s-node1   <none>           <none>            color=bluegreen,pod-template-hash=748cc6748f
green-748cc6748f-tv2rd   1/1     Running   0          67s   10.10.234.73   ws-k8s-node2   <none>           <none>            color=bluegreen,pod-template-hash=748cc6748f

#创建service文件
cat > service_bluegreen.yaml << EOF 
apiVersion: v1
kind: Service
metadata:
  name: lanlv
  namespace: blue-green
spec:
  type: NodePort
  ports:
  - port: 80
    nodePort: 30050
    name: http
  selector:
    color: green  #service关联color=green的标签的pod
EOF
kubectl apply -f service_bluegreen.yaml
kubectl get svc -n blue-green
NAME    TYPE       CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
lanlv   NodePort   10.105.133.209   <none>        80:30050/TCP   3h23m

#创建蓝色环境
cat > blue.yaml << EOF
apiVersion: apps/v1
kind: Deployment
metadata:
  name: blue
  namespace: blue-green
spec:
  replicas: 3
  selector:
   matchLabels:
      color: blue
  template:
   metadata:
    labels:
      color: blue
   spec:
    containers:
    - name: test2
      image: docker.io/library/tomcat
      imagePullPolicy: IfNotPresent
      ports:
         - containerPort: 8080
EOF
kubectl apply -f blue.yaml

#查看当前状态
kubectl get pods -n blue-green --show-labels
NAME                     READY   STATUS    RESTARTS   AGE     LABELS
blue-6c4db4cbcc-79mlg    1/1     Running   0          3h13m   color=blue,pod-template-hash=6c4db4cbcc
blue-6c4db4cbcc-pv76m    1/1     Running   0          3h13m   color=blue,pod-template-hash=6c4db4cbcc
green-7fc6f944df-5br85   1/1     Running   0          3h14m   color=green,pod-template-hash=7fc6f944df
green-7fc6f944df-jvblp   1/1     Running   0          3h14m   color=green,pod-template-hash=7fc6f944df

#当前状态————通过访问service代理的端口
curl 10.105.133.209:80
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p>

<p>For online documentation and support please refer to
<a href="<http://nginx.org/>">nginx.org</a>.<br/>
Commercial support is available at
<a href="<http://nginx.com/>">nginx.com</a>.</p>

<p><em>Thank you for using nginx.</em></p>
</body>
</html>
#也可以宿主机访问192.168.8.160（k8s集群master地址）:port（service定义的）来访问

#修改service的yaml文件，使其匹配到labels=blue的pod
...
- port: 8080
    nodePort: 30050
    name: http
  selector:
    color: blue  #service关联color=blue的标签的pod
...
kubectl apply -f service_bluegreen.yaml
#再次查看状态
curl 10.105.133.209:8080
<!doctype html><html lang="en"><head><title>HTTP Status 404 – Not Found</title><style type="text/css">body {font-family:Tahoma,Arial,sans-serif;} h1, h2, h3, b {color:white;background-color:#525D76;} h1 {font-size:22px;} h2 {font-size:16px;} h3 {font-size:14px;} p {font-size:12px;} a {color:black;} .line {height:1px;background-color:#525D76;border:none;}</style></head><body><h1>HTTP Status 404 – Not Found</h1><hr class="line" /><p><b>Type</b> Status Report</p><p><b>Description</b> The origin server did not find a current representation for the target resource or is not willing to disclose that one exists.</p><hr class="line" /><h3>Apache Tomcat/10.1.17</h3></body></html>[root@ws-k8s-master1 ~]#
#通过宿主机网页访问，清除缓存

使用Deployment进行金丝雀部署

金丝雀部署（Canary Deployment）是一种逐步发布新版本应用程序的部署策略。它的目标是在生产环境中逐渐引入新版本，以评估其性能、稳定性和用户反馈，同时最小化潜在的风险。

在金丝雀部署中，只有一小部分流量被导向到新版本，而大部分流量仍然被发送到稳定版本。这样可以在真实环境中进行测试，同时保持对用户的影响最小化。如果新版本表现良好，逐渐增加流量份额，直到完全切换到新版本。如果出现问题，可以快速回滚到稳定版本。又称灰度发布

#
kubectl set image deployment blue test2=docker.io/library/nginx -n blue-green && kubectl rollout pause deployment blue -n blue-green
#查看发现只运行了一个
#继续运行
kubectl rollout resume deployment blue -n blue-green
会开始更新剩余未更新的pod

#清理
kubectl delete -f service_bluegreen.yaml
kubectl delete -f blue.yaml
kubectl delete -f green.yaml

文章来源:https://blog.csdn.net/qq_72569959/article/details/135666337
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