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使用 kubectl 管理 HPA

本节描述了如何使用 kubectl 管理 HPA。本文件提供了以下操作的说明：

  • 创建 HPA

  • 获取 HPA 信息

  • 删除 HPA

  • 配置您的 HPA 以根据 CPU 或内存使用情况进行扩展

  • 如果您使用 Prometheus 等第三方工具进行指标监控，可以配置 HPA 根据自定义指标进行扩展

您可以通过 Rancher UI 创建、查看和删除 HPA。您还可以通过 Rancher UI 配置它们根据 CPU 或内存使用情况进行扩展。有关更多信息，请参阅 使用 Rancher UI 管理 HPA。要根据 CPU 或内存以外的其他指标扩展 HPA，您仍然需要 kubectl。

管理 HPA 的基本 kubectl 命令

如果您有 HPA 清单文件，可以使用 kubectl 创建、管理和删除 HPA：

  • 创建 HPA

    • 使用清单： kubectl create -f <HPA_MANIFEST>

    • 不使用清单（仅支持 CPU）： kubectl autoscale deployment hello-world --min=2 --max=5 --cpu-percent=50

  • 获取 HPA 信息

    • 基本: kubectl get hpa hello-world

    • 详细描述: kubectl describe hpa hello-world

  • 删除 HPA

    • kubectl delete hpa hello-world

HPA 清单定义示例

HPA 清单是用于通过 kubectl 管理 HPA 的配置文件。

以下代码片段演示了在 HPA 清单中使用不同指令的情况。请查看示例下方的列表，以了解每个指令的目的。

apiVersion: autoscaling/v2beta1
kind: HorizontalPodAutoscaler
metadata:
  name: hello-world
spec:
  scaleTargetRef:
    apiVersion: extensions/v1beta1
    kind: Deployment
    name: hello-world
  minReplicas: 1
  maxReplicas: 10
  metrics:
  - type: Resource
    resource:
      name: cpu
      targetAverageUtilization: 50
  - type: Resource
    resource:
      name: memory
      targetAverageValue: 100Mi
指令 说明

apiVersion: autoscaling/v2beta1

正在使用的 Kubernetes autoscaling API 组的版本。此示例清单使用的是 beta 版本，因此启用了基于 CPU 和内存的扩展。

name: hello-world

指示 HPA 正在对 hello-word 部署执行自动扩展。

minReplicas: 1

指示运行的副本最小数量不能低于 1。

maxReplicas: 10

指示部署中的副本最大数量不能超过 10。

targetAverageUtilization: 50

指示当平均运行的 Pod 使用超过 50% 的请求 CPU 时，部署将扩展 Pod。

targetAverageValue: 100Mi

指示当平均运行的 Pod 使用超过 100Mi 的内存时，部署将扩展 Pod。

配置 HPA 以使用资源指标（CPU 和内存）进行扩展

在 Rancher v2.0.7 及更高版本中创建的集群具备使用水平 Pod 自动扩展器所需的所有要求（metrics-server 和 Kubernetes 集群配置）。

运行以下命令以检查您的安装中是否可用指标：

$ kubectl top nodes
NAME                              CPU(cores)   CPU%      MEMORY(bytes)   MEMORY%
node-controlplane   196m         9%        1623Mi          42%
node-etcd           80m          4%        1090Mi          28%
node-worker         64m          3%        1146Mi          29%
$ kubectl -n kube-system top pods
NAME                                   CPU(cores)   MEMORY(bytes)
canal-pgldr                            18m          46Mi
canal-vhkgr                            20m          45Mi
canal-x5q5v                            17m          37Mi
canal-xknnz                            20m          37Mi
kube-dns-7588d5b5f5-298j2              0m           22Mi
kube-dns-autoscaler-5db9bbb766-t24hw   0m           5Mi
metrics-server-97bc649d5-jxrlt         0m           12Mi
$ kubectl -n kube-system logs -l k8s-app=metrics-server
I1002 12:55:32.172841       1 heapster.go:71] /metrics-server --source=kubernetes.summary_api:https://kubernetes.default.svc?kubeletHttps=true&kubeletPort=10250&useServiceAccount=true&insecure=true
I1002 12:55:32.172994       1 heapster.go:72] Metrics Server version v0.2.1
I1002 12:55:32.173378       1 configs.go:61] Using Kubernetes client with master "https://kubernetes.default.svc" and version
I1002 12:55:32.173401       1 configs.go:62] Using kubelet port 10250
I1002 12:55:32.173946       1 heapster.go:128] Starting with Metric Sink
I1002 12:55:32.592703       1 serving.go:308] Generated self-signed cert (apiserver.local.config/certificates/apiserver.crt, apiserver.local.config/certificates/apiserver.key)
I1002 12:55:32.925630       1 heapster.go:101] Starting Heapster API server...
[restful] 2018/10/02 12:55:32 log.go:33: [restful/swagger] listing is available at https:///swaggerapi
[restful] 2018/10/02 12:55:32 log.go:33: [restful/swagger] https:///swaggerui/ is mapped to folder /swagger-ui/
I1002 12:55:32.928597       1 serve.go:85] Serving securely on 0.0.0.0:443

配置 HPA 以使用 Prometheus 的自定义指标进行扩展

您可以配置 HPA 以根据第三方软件提供的自定义指标进行自动扩展。使用第三方软件进行自动扩展的最常见用例是基于应用程序级别的指标（即每秒 HTTP 请求）。HPA使用`custom.metrics.k8s.io` API来获取这些指标。通过部署自定义指标适配器来启用此API，以便进行指标收集。

在本示例中，我们将使用 Prometheus。我们从以下假设开始：

  • Prometheus已在集群中部署。

  • Prometheus已正确配置，并从Pod、节点、命名空间等收集了适当的指标。

  • Prometheus在以下URL和端口上可用：http://prometheus.mycompany.io:80

Prometheus可以在Rancher v2.0目录中进行部署。如果它尚未在您的集群中运行，请从Rancher目录中部署它。

为了让 HPA 使用 Prometheus 的自定义指标，您需要在集群的 kube-system 命名空间中安装软件包 k8s-prometheus-adapter。要安装`k8s-prometheus-adapter`，我们使用位于 banzai-charts的Helm图表。

  1. 在您的集群中初始化Helm。

      # kubectl -n kube-system create serviceaccount tiller
  kubectl create clusterrolebinding tiller --clusterrole cluster-admin --serviceaccount=kube-system:tiller
  helm init --service-account tiller

  2. 从GitHub克隆`banzai-charts`仓库：

      # git clone https://github.com/banzaicloud/banzai-charts

  3. 安装`prometheus-adapter`图表，指定Prometheus的URL和端口号。

      # helm install --name prometheus-adapter banzai-charts/prometheus-adapter --set prometheus.url="http://prometheus.mycompany.io",prometheus.port="80" --namespace kube-system

  4. 检查`prometheus-adapter`是否正常运行。检查`kube-system`命名空间中的服务Pod和日志。

  5. 检查服务Pod是否为`Running`。输入以下命令。 ` # kubectl get pods -n kube-system ` 从结果输出中，查找状态为`Running`。 + NAME READY STATUS RESTARTS AGE …​ prometheus-adapter-prometheus-adapter-568674d97f-hbzfx 1/1 Running 0 7h …​ +

  6. 检查服务日志，以确保服务正常运行，输入以下命令。 ` # kubectl logs prometheus-adapter-prometheus-adapter-568674d97f-hbzfx -n kube-system ` 然后查看日志输出以确认服务正在运行。

    .Prometheus Adaptor Logs [%collapsible] ====== ...
I0724 10:18:45.696679       1 round_trippers.go:436] GET https://10.43.0.1:443/api/v1/namespaces/default/pods?labelSelector=app%3Dhello-world 200 OK in 2 milliseconds
I0724 10:18:45.696695       1 round_trippers.go:442] Response Headers:
I0724 10:18:45.696699       1 round_trippers.go:445]     Date: Tue, 24 Jul 2018 10:18:45 GMT
I0724 10:18:45.696703       1 round_trippers.go:445]     Content-Type: application/json
I0724 10:18:45.696706       1 round_trippers.go:445]     Content-Length: 2581
I0724 10:18:45.696766       1 request.go:836] Response Body: {"kind":"PodList","apiVersion":"v1","metadata":{"selfLink":"/api/v1/namespaces/default/pods","resourceVersion":"6237"},"items":[{"metadata":{"name":"hello-world-54764dfbf8-q6l82","generateName":"hello-world-54764dfbf8-","namespace":"default","selfLink":"/api/v1/namespaces/default/pods/hello-world-54764dfbf8-q6l82","uid":"484cb929-8f29-11e8-99d2-067cac34e79c","resourceVersion":"4066","creationTimestamp":"2018-07-24T10:06:50Z","labels":{"app":"hello-world","pod-template-hash":"1032089694"},"annotations":{"cni.projectcalico.org/podIP":"10.42.0.7/32"},"ownerReferences":[{"apiVersion":"extensions/v1beta1","kind":"ReplicaSet","name":"hello-world-54764dfbf8","uid":"4849b9b1-8f29-11e8-99d2-067cac34e79c","controller":true,"blockOwnerDeletion":true}]},"spec":{"volumes":[{"name":"default-token-ncvts","secret":{"secretName":"default-token-ncvts","defaultMode":420}}],"containers":[{"name":"hello-world","image":"rancher/hello-world","ports":[{"containerPort":80,"protocol":"TCP"}],"resources":{"requests":{"cpu":"500m","memory":"64Mi"}},"volumeMounts":[{"name":"default-token-ncvts","readOnly":true,"mountPath":"/var/run/secrets/kubernetes.io/serviceaccount"}],"terminationMessagePath":"/dev/termination-log","terminationMessagePolicy":"File","imagePullPolicy":"Always"}],"restartPolicy":"Always","terminationGracePeriodSeconds":30,"dnsPolicy":"ClusterFirst","serviceAccountName":"default","serviceAccount":"default","nodeName":"34.220.18.140","securityContext":{},"schedulerName":"default-scheduler","tolerations":[{"key":"node.kubernetes.io/not-ready","operator":"Exists","effect":"NoExecute","tolerationSeconds":300},{"key":"node.kubernetes.io/unreachable","operator":"Exists","effect":"NoExecute","tolerationSeconds":300}]},"status":{"phase":"Running","conditions":[{"type":"Initialized","status":"True","lastProbeTime":null,"lastTransitionTime":"2018-07-24T10:06:50Z"},{"type":"Ready","status":"True","lastProbeTime":null,"lastTransitionTime":"2018-07-24T10:06:54Z"},{"type":"PodScheduled","status":"True","lastProbeTime":null,"lastTransitionTime":"2018-07-24T10:06:50Z"}],"hostIP":"34.220.18.140","podIP":"10.42.0.7","startTime":"2018-07-24T10:06:50Z","containerStatuses":[{"name":"hello-world","state":{"running":{"startedAt":"2018-07-24T10:06:54Z"}},"lastState":{},"ready":true,"restartCount":0,"image":"rancher/hello-world:latest","imageID":"docker-pullable://rancher/hello-world@sha256:4b1559cb4b57ca36fa2b313a3c7dde774801aa3a2047930d94e11a45168bc053","containerID":"docker://cce4df5fc0408f03d4adf82c90de222f64c302bf7a04be1c82d584ec31530773"}],"qosClass":"Burstable"}}]}
I0724 10:18:45.699525       1 api.go:74] GET http://prometheus-server.prometheus.34.220.18.140.xip.io/api/v1/query?query=sum%28rate%28container_fs_read_seconds_total%7Bpod_name%3D%22hello-world-54764dfbf8-q6l82%22%2Ccontainer_name%21%3D%22POD%22%2Cnamespace%3D%22default%22%7D%5B5m%5D%29%29by%28pod_name%29&time=1532427525.697 200 OK
I0724 10:18:45.699620       1 api.go:93] Response Body: {"status":"success","data":{"resultType":"vector","result":[{"metric":{"pod_name":"hello-world-54764dfbf8-q6l82"},"value":[1532427525.697,"0"]}]}}
I0724 10:18:45.699939       1 wrap.go:42] GET /apis/custom.metrics.k8s.io/v1beta1/namespaces/default/pods/%2A/fs_read?labelSelector=app%3Dhello-world: (12.431262ms) 200 [[kube-controller-manager/v1.10.1 (linux/amd64) kubernetes/d4ab475/system:serviceaccount:kube-system:horizontal-pod-autoscaler] 10.42.0.0:24268]
I0724 10:18:51.727845       1 request.go:836] Request Body: {"kind":"SubjectAccessReview","apiVersion":"authorization.k8s.io/v1beta1","metadata":{"creationTimestamp":null},"spec":{"nonResourceAttributes":{"path":"/","verb":"get"},"user":"system:anonymous","group":["system:unauthenticated"]},"status":{"allowed":false}}
... ======

  7. 检查指标API是否可以从kubectl访问。

    • 如果您直接访问集群，请在kubectl配置中以以下格式输入您的服务器URL：https://<Kubernetes_URL>:6443。

      # kubectl get --raw /apis/custom.metrics.k8s.io/v1beta1

      如果API可访问，您应该收到类似于以下内容的输出。

      API响应

      {"kind":"APIResourceList","apiVersion":"v1","groupVersion":"custom.metrics.k8s.io/v1beta1","resources":[{"name":"pods/fs_usage_bytes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/memory_rss","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/spec_cpu_period","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/cpu_cfs_throttled","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_io_time","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_read","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_sector_writes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/cpu_user","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/last_seen","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/tasks_state","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/spec_cpu_quota","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/start_time_seconds","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_limit_bytes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_write","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/memory_cache","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/memory_usage_bytes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/cpu_cfs_periods","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/cpu_cfs_throttled_periods","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_reads_merged","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/memory_working_set_bytes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/network_udp_usage","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_inodes_free","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_inodes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_io_time_weighted","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/memory_failures","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/memory_swap","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/spec_cpu_shares","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/spec_memory_swap_limit_bytes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/cpu_usage","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_io_current","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_writes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/memory_failcnt","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_reads","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_writes_bytes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_writes_merged","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/network_tcp_usage","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/memory_max_usage_bytes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/spec_memory_limit_bytes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/spec_memory_reservation_limit_bytes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/cpu_load_average_10s","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/cpu_system","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_reads_bytes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_sector_reads","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]}]}

    • 如果您通过Rancher访问集群，请在kubectl配置中以以下格式输入您的服务器URL：https://<RANCHER_URL>/k8s/clusters/<CLUSTER_ID>。在 API 路径中添加后缀`/k8s/clusters/<CLUSTER_ID>`。

      # kubectl get --raw /k8s/clusters/<CLUSTER_ID>/apis/custom.metrics.k8s.io/v1beta1

      如果API可访问，您应该收到类似于以下内容的输出。

      API响应

      {"kind":"APIResourceList","apiVersion":"v1","groupVersion":"custom.metrics.k8s.io/v1beta1","resources":[{"name":"pods/fs_usage_bytes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/memory_rss","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/spec_cpu_period","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/cpu_cfs_throttled","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_io_time","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_read","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_sector_writes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/cpu_user","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/last_seen","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/tasks_state","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/spec_cpu_quota","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/start_time_seconds","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_limit_bytes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_write","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/memory_cache","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/memory_usage_bytes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/cpu_cfs_periods","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/cpu_cfs_throttled_periods","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_reads_merged","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/memory_working_set_bytes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/network_udp_usage","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_inodes_free","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_inodes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_io_time_weighted","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/memory_failures","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/memory_swap","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/spec_cpu_shares","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/spec_memory_swap_limit_bytes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/cpu_usage","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_io_current","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_writes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/memory_failcnt","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_reads","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_writes_bytes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_writes_merged","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/network_tcp_usage","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/memory_max_usage_bytes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/spec_memory_limit_bytes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/spec_memory_reservation_limit_bytes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/cpu_load_average_10s","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/cpu_system","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_reads_bytes","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]},{"name":"pods/fs_sector_reads","singularName":"","namespaced":true,"kind":"MetricValueList","verbs":["get"]}]}