Kubernetes：如何扩展我的 pod

Question

我是 Kubernetes 新手。我尝试扩展我的豆荚。首先我启动了 3 个 pod：

./cluster/kubectl.sh run my-nginx --image=nginx --replicas=3 --port=80

开始有 3 个吊舱。首先，我尝试使用复制控制器来扩大/缩小规模，但这并不存在。现在好像是一个replicaSet。

./cluster/kubectl.sh get rs
NAME                  DESIRED   CURRENT   AGE
my-nginx-2494149703   3         3         9h

我尝试更改我的副本集中描述的副本数量：

./cluster/kubectl.sh scale --replicas=5 rs/my-nginx-2494149703
replicaset "my-nginx-2494149703" scaled

但我仍然看到我的 3 个原始豆荚

./cluster/kubectl.sh get pods
NAME                        READY     STATUS    RESTARTS   AGE
my-nginx-2494149703-04xrd   1/1       Running   0          9h
my-nginx-2494149703-h3krk   1/1       Running   0          9h
my-nginx-2494149703-hnayu   1/1       Running   0          9h

我希望看到 5 个豆荚。

./cluster/kubectl.sh describe rs/my-nginx-2494149703
Name:       my-nginx-2494149703
Namespace:  default
Image(s):   nginx
Selector:   pod-template-hash=2494149703,run=my-nginx
Labels:     pod-template-hash=2494149703
        run=my-nginx
Replicas:   3 current / 3 desired
Pods Status:    3 Running / 0 Waiting / 0 Succeeded / 0 Failed

为什么不扩大规模？我是否还必须更改部署中的某些内容？

当我在放大后描述我的 rs 时，我看到了这样的内容： （这里我尝试从一个正在运行的 pod 扩展到 3 个正在运行的 pod）。但它仍然是一个正在运行的吊舱。其他2个立即启动并杀死

  34s       34s     1   {replicaset-controller }            Normal      SuccessfulCreate    Created pod: my-nginx-1908062973-lylsz
  34s       34s     1   {replicaset-controller }            Normal      SuccessfulCreate    Created pod: my-nginx-1908062973-5rv8u
  34s       34s     1   {replicaset-controller }            Normal      SuccessfulDelete    Deleted pod: my-nginx-1908062973-lylsz
  34s       34s     1   {replicaset-controller }            Normal      SuccessfulDelete    Deleted pod: my-nginx-1908062973-5rv8u

Answer 1

这对我有用

kubectl scale --replicas=<expected_replica_num> deployment <deployment_label_name>

例子

# kubectl scale --replicas=3 deployment xyz

Answer 2

TL;DR：您需要扩展部署而不是直接扩展副本集。

如果您尝试扩展副本集，那么它将（在很短的时间内）新的计数为 5。但部署控制器将看到副本集的当前计数为 5，因为它知道它应该是 3，它会将其重置回 3。通过手动修改为您创建的副本集，您正在与系统控制器进行斗争（它是不倦的，并且几乎总是会比您更持久）。

Answer 3

kubectl run my-nginx --image=nginx --replicas=3 --port=80 在这个kubectl run 中将创建一个部署或作业来管理创建的容器。
部署--> ReplicaSet-->Pod 这就是 Kubernetes 的工作原理。
如果您更改底层 对象，其更高级别 对象将撤消您的更改。您必须更改顶级 对象。

Answer 4

将其缩小到零，然后缩小到您需要的 pod 数量（猜想它等于 3）

kubectl scale deployment <deployment-name> --replicas=0 -n <namespace>
kubectl scale deployment <deployment-name> --replicas=3 -n <namespace>

Answer 5

不确定这是否是我开始使用 kubernetes 的最佳方式，但我通过更新我的 yaml 文件来做到这一点

# app.yaml
apiVersion: apps/v1
...
spec:
  replicas: <new value>

并运行$ kubectl scale -f app.yaml --replicas=<new value>

您可以通过运行$ kubectl get pods 来验证您的新副本数量

就我而言，我也有兴趣在谷歌云上缩减我的虚拟机。我用$ gcloud container clusters resize appName --size=1 --zone "my-zone" 做到了这一点

Answer 6

下面的例子展示了你应该如何扩大/缩小你的“pods/resource/deployments”。

k8smaster@k8smaster:~/debashish$ more createdeb_deployment1.yaml 


--- 
apiVersion: apps/v1beta2
kind: Deployment
metadata: 
  name: debdeploy-webserver
spec: 
  replicas: 1
  selector: 
    matchLabels: 
      app: debdeploy1webserver
  template: 
    metadata: 
      labels: 
        app: debdeploy1webserver
    spec: 
      containers: 
        - 
          image: "docker.io/debu3645/debapachewebserver:v1"
          name: deb-deploy1-container 
          ports: 
            - 
              containerPort: 6060

已创建部署 -->

**kubectl -n debns1 create -f createdeb_deployment1.yaml**




k8smaster@k8smaster:~/debashish$ `kubectl scale --replicas=5 **deployment**/debdeploy-webserver -n debns1`

（扩大 5 个部署）

k8smaster@k8smaster:~/debashish$ kubectl get pods -n debns1


NAME                                   READY   STATUS    RESTARTS   AGE
debdeploy-webserver-7cf4fb74c5-8wvzx   1/1     Running   0          16s
debdeploy-webserver-7cf4fb74c5-jrf6v   1/1     Running   0          16s
debdeploy-webserver-7cf4fb74c5-m9fpw   1/1     Running   0          16s
debdeploy-webserver-7cf4fb74c5-q9n7r   1/1     Running   0          16s
debdeploy-webserver-7cf4fb74c5-ttw6p   1/1     Running   1          19h
resourcepod-deb1                       1/1     Running   5          6d18h




k8smaster@k8smaster:~/debashish$ **kubectl get ep -n debns1**



NAME                ENDPOINTS                                                     AGE
frontend-svc-deb    192.168.1.10:80,192.168.1.11:80,192.168.1.12:80 + 2 more...   18h
frontend-svc1-deb   192.168.1.8:80                                                14d
frontend-svc2-deb   192.168.1.8:80                                                5d19h




k8smaster@k8smaster:~/debashish$ **kubectl scale --replicas=2** deployment/debdeploy-webserver -n debns1 

（从 5 缩小到 2）

deployment.extensions/debdeploy-webserver 扩展

k8smaster@k8smaster:~/debashish$ **kubectl get pods -n debns1**


NAME                                   READY   STATUS        RESTARTS   AGE
debdeploy-webserver-7cf4fb74c5-8wvzx   1/1     Terminating   0          35m
debdeploy-webserver-7cf4fb74c5-jrf6v   1/1     Terminating   0          35m
debdeploy-webserver-7cf4fb74c5-m9fpw   1/1     Terminating   0          35m
debdeploy-webserver-7cf4fb74c5-q9n7r   1/1     Running       0          35m
debdeploy-webserver-7cf4fb74c5-ttw6p   1/1     Running       1          19h
resourcepod-deb1                       1/1     Running       5          6d19h


k8smaster@k8smaster:~/debashish$ **kubectl get pods -n debns1**


NAME                                   READY   STATUS    RESTARTS   AGE
debdeploy-webserver-7cf4fb74c5-q9n7r   1/1     Running   0          37m
debdeploy-webserver-7cf4fb74c5-ttw6p   1/1     Running   1          19h
resourcepod-deb1                       1/1     Running   5          6d19h

k8smaster@k8smaster:~/debashish$ kubectl **scale --current-replicas=4 --replicas=2** deployment/debdeploy-webserver -n debns1  (Check the current no. of deployments. If current replication is 4, then bring it down to 2, else dont do anything)


error: Expected replicas to be 4, was 2


k8smaster@k8smaster:~/debashish$ **kubectl scale --current-replicas=3 --replicas=10 deployment/debdeploy-webserver -n debns1**


error: Expected replicas to be 3, was 2


k8smaster@k8smaster:~/debashish$ **kubectl scale --current-replicas=2 --replicas=10 deployment/debdeploy-webserver -n debns1**

deployment.extensions/debdeploy-webserver 扩展

k8smaster@k8smaster:~/debashish$ **kubectl get pods -n debns1**


    NAME                                   READY   STATUS              RESTARTS   AGE
    debdeploy-webserver-7cf4fb74c5-46bxg   1/1     Running             0          6s
    debdeploy-webserver-7cf4fb74c5-d6qsx   0/1     ContainerCreating   0          6s
    debdeploy-webserver-7cf4fb74c5-fdq6v   1/1     Running             0          6s
    debdeploy-webserver-7cf4fb74c5-gd87t   1/1     Running             0          6s
    debdeploy-webserver-7cf4fb74c5-kqdbj   0/1     ContainerCreating   0          6s
    debdeploy-webserver-7cf4fb74c5-q9n7r   1/1     Running             0          47m
    debdeploy-webserver-7cf4fb74c5-qjvm6   1/1     Running             0          6s
    debdeploy-webserver-7cf4fb74c5-skxq4   0/1     ContainerCreating   0          6s
    debdeploy-webserver-7cf4fb74c5-ttw6p   1/1     Running             1          19h
    debdeploy-webserver-7cf4fb74c5-wlc7q   0/1     ContainerCreating   0          6s
    resourcepod-deb1                       1/1     Running             5          6d19h