没有 pod 指标的 Kubernetes答案

【问题标题】：Kubernetes without pod metrics没有 pod 指标的 Kubernetes
【发布时间】：2020-05-22 21:05:38
【问题描述】：

我正在尝试将指标部署到 Kubernetes，但发生了一些非常奇怪的事情，我有一个工人和一个主人。我有以下 pod 列表：

NAMESPACE     NAME                                              READY   STATUS    RESTARTS   AGE     IP               NODE                      NOMINATED NODE   READINESS GATES
default       php-apache-774ff9d754-d7vp9                       1/1     Running   0          2m43s   192.168.77.172   master-node               <none>           <none>
kube-system   calico-kube-controllers-6b9d4c8765-x7pql          1/1     Running   2          4h11m   192.168.77.130   master-node               <none>           <none>
kube-system   calico-node-d4rnh                                 0/1     Running   1          4h11m   10.221.194.166   master-node               <none>           <none>
kube-system   calico-node-hwkmd                                 0/1     Running   1          4h11m   10.221.195.58    free5gc-virtual-machine   <none>           <none>
kube-system   coredns-6955765f44-kf4dr                          1/1     Running   1          4h20m   192.168.178.65   free5gc-virtual-machine   <none>           <none>
kube-system   coredns-6955765f44-s58rf                          1/1     Running   1          4h20m   192.168.178.66   free5gc-virtual-machine   <none>           <none>
kube-system   etcd-free5gc-virtual-machine                      1/1     Running   1          4h21m   10.221.195.58    free5gc-virtual-machine   <none>           <none>
kube-system   kube-apiserver-free5gc-virtual-machine            1/1     Running   1          4h21m   10.221.195.58    free5gc-virtual-machine   <none>           <none>
kube-system   kube-controller-manager-free5gc-virtual-machine   1/1     Running   1          4h21m   10.221.195.58    free5gc-virtual-machine   <none>           <none>
kube-system   kube-proxy-brvdg                                  1/1     Running   1          4h19m   10.221.194.166   master-node               <none>           <none>
kube-system   kube-proxy-lfzjw                                  1/1     Running   1          4h20m   10.221.195.58    free5gc-virtual-machine   <none>           <none>
kube-system   kube-scheduler-free5gc-virtual-machine            1/1     Running   1          4h21m   10.221.195.58    free5gc-virtual-machine   <none>           <none>
kube-system   metrics-server-86c6d8b9bf-p2hh8                   1/1     Running   0          2m43s   192.168.77.171   master-node               <none>           <none>

当我尝试获取指标时，我看到以下内容：

NAME         REFERENCE               TARGETS         MINPODS   MAXPODS   REPLICAS   AGE
php-apache   Deployment/php-apache   <unknown>/50%   1         10        1          3m58s
free5gc@free5gc-virtual-machine:~/Desktop/metrics-server/deploy$
free5gc@free5gc-virtual-machine:~/Desktop/metrics-server/deploy$
free5gc@free5gc-virtual-machine:~/Desktop/metrics-server/deploy$
free5gc@free5gc-virtual-machine:~/Desktop/metrics-server/deploy$ kubectl top nodes
Error from server (ServiceUnavailable): the server is currently unable to handle the request (get nodes.metrics.k8s.io)
free5gc@free5gc-virtual-machine:~/Desktop/metrics-server/deploy$
free5gc@free5gc-virtual-machine:~/Desktop/metrics-server/deploy$
free5gc@free5gc-virtual-machine:~/Desktop/metrics-server/deploy$
free5gc@free5gc-virtual-machine:~/Desktop/metrics-server/deploy$ kubectl top pods --all-namespaces
Error from server (ServiceUnavailable): the server is currently unable to handle the request (get pods.metrics.k8s.io)

最后，我看到了 metrics-server 的输出日志 (v=6)：

free5gc@free5gc-virtual-machine:~/Desktop/metrics-server/deploy$ kubectl logs metrics-server-86c6d8b9bf-p2hh8  -n kube-system
I0206 18:16:18.657605       1 serving.go:273] Generated self-signed cert (/tmp/apiserver.crt, /tmp/apiserver.key)
I0206 18:16:19.367356       1 round_trippers.go:405] GET https://10.96.0.1:443/api/v1/namespaces/kube-system/configmaps/extension-apiserver-authentication 200 OK in 7 milliseconds
I0206 18:16:19.370573       1 round_trippers.go:405] GET https://10.96.0.1:443/api/v1/namespaces/kube-system/configmaps/extension-apiserver-authentication 200 OK in 1 milliseconds
I0206 18:16:19.373245       1 round_trippers.go:405] GET https://10.96.0.1:443/api/v1/namespaces/kube-system/configmaps/extension-apiserver-authentication 200 OK in 1 milliseconds
I0206 18:16:19.375024       1 round_trippers.go:405] GET https://10.96.0.1:443/api/v1/namespaces/kube-system/configmaps/extension-apiserver-authentication 200 OK in 1 milliseconds
[restful] 2020/02/06 18:16:19 log.go:33: [restful/swagger] listing is available at https://:4443/swaggerapi
[restful] 2020/02/06 18:16:19 log.go:33: [restful/swagger] https://:4443/swaggerui/ is mapped to folder /swagger-ui/
I0206 18:16:19.421207       1 healthz.go:83] Installing healthz checkers:"ping", "poststarthook/generic-apiserver-start-informers", "healthz"
I0206 18:16:19.421641       1 serve.go:96] Serving securely on [::]:4443
I0206 18:16:19.421873       1 reflector.go:202] Starting reflector *v1.Pod (0s) from github.com/kubernetes-incubator/metrics-server/vendor/k8s.io/client-go/informers/factory.go:130
I0206 18:16:19.421891       1 reflector.go:240] Listing and watching *v1.Pod from github.com/kubernetes-incubator/metrics-server/vendor/k8s.io/client-go/informers/factory.go:130
I0206 18:16:19.421914       1 reflector.go:202] Starting reflector *v1.Node (0s) from github.com/kubernetes-incubator/metrics-server/vendor/k8s.io/client-go/informers/factory.go:130
I0206 18:16:19.421929       1 reflector.go:240] Listing and watching *v1.Node from github.com/kubernetes-incubator/metrics-server/vendor/k8s.io/client-go/informers/factory.go:130
I0206 18:16:19.423052       1 round_trippers.go:405] GET https://10.96.0.1:443/api/v1/nodes?limit=500&resourceVersion=0 200 OK in 1 milliseconds
I0206 18:16:19.424261       1 round_trippers.go:405] GET https://10.96.0.1:443/api/v1/pods?limit=500&resourceVersion=0 200 OK in 2 milliseconds
I0206 18:16:19.425586       1 round_trippers.go:405] GET https://10.96.0.1:443/api/v1/nodes?resourceVersion=38924&timeoutSeconds=481&watch=true 200 OK in 0 milliseconds
I0206 18:16:19.433545       1 round_trippers.go:405] GET https://10.96.0.1:443/api/v1/pods?resourceVersion=39246&timeoutSeconds=582&watch=true 200 OK in 0 milliseconds
I0206 18:16:49.388514       1 manager.go:99] Beginning cycle, collecting metrics...
I0206 18:16:49.388598       1 manager.go:95] Scraping metrics from 2 sources
I0206 18:16:49.395742       1 manager.go:120] Querying source: kubelet_summary:free5gc-virtual-machine
I0206 18:16:49.400574       1 manager.go:120] Querying source: kubelet_summary:master-node
I0206 18:16:49.413751       1 round_trippers.go:405] GET https://10.221.194.166:10250/stats/summary/ 200 OK in 13 milliseconds
I0206 18:16:49.414317       1 round_trippers.go:405] GET https://10.221.195.58:10250/stats/summary/ 200 OK in 18 milliseconds
I0206 18:16:49.417044       1 manager.go:150] ScrapeMetrics: time: 28.428677ms, nodes: 2, pods: 13
I0206 18:16:49.417062       1 manager.go:115] ...Storing metrics...
I0206 18:16:49.417083       1 manager.go:126] ...Cycle complete
free5gc@free5gc-virtual-machine:~/Desktop/metrics-server/deploy$ kubectl logs metrics-server-86c6d8b9bf-p2hh8  -n kube-system
I0206 18:16:18.657605       1 serving.go:273] Generated self-signed cert (/tmp/apiserver.crt, /tmp/apiserver.key)
I0206 18:16:19.367356       1 round_trippers.go:405] GET https://10.96.0.1:443/api/v1/namespaces/kube-system/configmaps/extension-apiserver-authentication 200 OK in 7 milliseconds
I0206 18:16:19.370573       1 round_trippers.go:405] GET https://10.96.0.1:443/api/v1/namespaces/kube-system/configmaps/extension-apiserver-authentication 200 OK in 1 milliseconds
I0206 18:16:19.373245       1 round_trippers.go:405] GET https://10.96.0.1:443/api/v1/namespaces/kube-system/configmaps/extension-apiserver-authentication 200 OK in 1 milliseconds
I0206 18:16:19.375024       1 round_trippers.go:405] GET https://10.96.0.1:443/api/v1/namespaces/kube-system/configmaps/extension-apiserver-authentication 200 OK in 1 milliseconds
[restful] 2020/02/06 18:16:19 log.go:33: [restful/swagger] listing is available at https://:4443/swaggerapi
[restful] 2020/02/06 18:16:19 log.go:33: [restful/swagger] https://:4443/swaggerui/ is mapped to folder /swagger-ui/
I0206 18:16:19.421207       1 healthz.go:83] Installing healthz checkers:"ping", "poststarthook/generic-apiserver-start-informers", "healthz"
I0206 18:16:19.421641       1 serve.go:96] Serving securely on [::]:4443
I0206 18:16:19.421873       1 reflector.go:202] Starting reflector *v1.Pod (0s) from github.com/kubernetes-incubator/metrics-server/vendor/k8s.io/client-go/informers/factory.go:130
I0206 18:16:19.421891       1 reflector.go:240] Listing and watching *v1.Pod from github.com/kubernetes-incubator/metrics-server/vendor/k8s.io/client-go/informers/factory.go:130
I0206 18:16:19.421914       1 reflector.go:202] Starting reflector *v1.Node (0s) from github.com/kubernetes-incubator/metrics-server/vendor/k8s.io/client-go/informers/factory.go:130
I0206 18:16:19.421929       1 reflector.go:240] Listing and watching *v1.Node from github.com/kubernetes-incubator/metrics-server/vendor/k8s.io/client-go/informers/factory.go:130
I0206 18:16:19.423052       1 round_trippers.go:405] GET https://10.96.0.1:443/api/v1/nodes?limit=500&resourceVersion=0 200 OK in 1 milliseconds
I0206 18:16:19.424261       1 round_trippers.go:405] GET https://10.96.0.1:443/api/v1/pods?limit=500&resourceVersion=0 200 OK in 2 milliseconds
I0206 18:16:19.425586       1 round_trippers.go:405] GET https://10.96.0.1:443/api/v1/nodes?resourceVersion=38924&timeoutSeconds=481&watch=true 200 OK in 0 milliseconds
I0206 18:16:19.433545       1 round_trippers.go:405] GET https://10.96.0.1:443/api/v1/pods?resourceVersion=39246&timeoutSeconds=582&watch=true 200 OK in 0 milliseconds
I0206 18:16:49.388514       1 manager.go:99] Beginning cycle, collecting metrics...
I0206 18:16:49.388598       1 manager.go:95] Scraping metrics from 2 sources
I0206 18:16:49.395742       1 manager.go:120] Querying source: kubelet_summary:free5gc-virtual-machine
I0206 18:16:49.400574       1 manager.go:120] Querying source: kubelet_summary:master-node
I0206 18:16:49.413751       1 round_trippers.go:405] GET https://10.221.194.166:10250/stats/summary/ 200 OK in 13 milliseconds
I0206 18:16:49.414317       1 round_trippers.go:405] GET https://10.221.195.58:10250/stats/summary/ 200 OK in 18 milliseconds
I0206 18:16:49.417044       1 manager.go:150] ScrapeMetrics: time: 28.428677ms, nodes: 2, pods: 13
I0206 18:16:49.417062       1 manager.go:115] ...Storing metrics...
I0206 18:16:49.417083       1 manager.go:126] ...Cycle complete

使用 v=10 的日志输出，我什至可以看到每个 pod 的运行状况详细信息，但在运行 kubectl get hpa 或 kubectl top nodes 时什么也看不到。有人可以给我一个提示吗？此外，我的指标清单是：

---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: metrics-server
  namespace: kube-system
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: metrics-server
  namespace: kube-system
  labels:
    k8s-app: metrics-server
spec:
  selector:
    matchLabels:
      k8s-app: metrics-server
  template:
    metadata:
      name: metrics-server
      labels:
        k8s-app: metrics-server
    spec:
      serviceAccountName: metrics-server
      volumes:
      # mount in tmp so we can safely use from-scratch images and/or read-only containers
      - name: tmp-dir
        emptyDir: {}
      containers:
      - name: metrics-server
        image: k8s.gcr.io/metrics-server-amd64:v0.3.1
        args:
          - /metrics-server
          - --metric-resolution=30s
          - --requestheader-allowed-names=aggregator
          - --cert-dir=/tmp
          - --secure-port=4443
          - --kubelet-insecure-tls
          - --v=6
          - --kubelet-preferred-address-types=InternalIP,Hostname,InternalDNS,ExternalDNS,ExternalIP
            #- --kubelet-preferred-address-types=InternalIP
        ports:
        - name: main-port
          containerPort: 4443
          protocol: TCP
        securityContext:
          readOnlyRootFilesystem: true
          runAsNonRoot: true
          runAsUser: 1000
        imagePullPolicy: Always
        volumeMounts:
        - name: tmp-dir
          mountPath: /tmp
      nodeSelector:
        beta.kubernetes.io/os: linux
        kubernetes.io/arch: "amd64"

我可以看到以下内容：

free5gc@free5gc-virtual-machine:~/Desktop/metrics-server/deploy$ kubectl get apiservice v1beta1.metrics.k8s.io -o yaml
apiVersion: apiregistration.k8s.io/v1
kind: APIService
metadata:
  creationTimestamp: "2020-02-06T18:57:28Z"
  name: v1beta1.metrics.k8s.io
  resourceVersion: "45583"
  selfLink: /apis/apiregistration.k8s.io/v1/apiservices/v1beta1.metrics.k8s.io
  uid: ca439221-b987-4c13-b0e0-8d2bb237e612
spec:
  group: metrics.k8s.io
  groupPriorityMinimum: 100
  insecureSkipTLSVerify: true
  service:
    name: metrics-server
    namespace: kube-system
    port: 443
  version: v1beta1
  versionPriority: 100
status:
  conditions:
  - lastTransitionTime: "2020-02-06T18:57:28Z"
    message: 'failing or missing response from https://10.110.144.114:443/apis/metrics.k8s.io/v1beta1:
      Get https://10.110.144.114:443/apis/metrics.k8s.io/v1beta1: dial tcp 10.110.144.114:443:
      connect: no route to host'
    reason: FailedDiscoveryCheck
    status: "False"
    type: Available

【问题讨论】：

Metrics 服务需要时间来预热您是否在等待足够长的时间后尝试！你还能看到问题吗！
您是否真的为该部署创建了服务资源？检查 kube-apiserver 日志。
您使用的是云环境还是本地机器？我猜你用过这个教程：kubernetes.io/docs/tasks/run-application/…你等了多久？您应该等待 5-10 分钟，具体取决于您的环境。一段时间后问题仍然存在？
@DT。是的，我确实等了一段时间来检查它。我很确定该错误与它指出的最后一部分有关：conditions: - lastTransitionTime: "2020-02-06T18:57:28Z" message: 'failing or missing response from https://10.110.144.114:443/apis/metrics.k8s.io/v1beta1: Get https://10.110.144.114:443/apis/metrics.k8s.io/v1beta1: dial tcp 10.110.144.114:443: connect: no route to host' reason: FailedDiscoveryCheck status: "False"@TimAllclair，我该如何检查它？ @PjoterS 我并没有真正遵循任何特定的教程，但遵循它仍然不起作用
您的问题似乎已在 github 上报告 ..github.com/kubernetes/kubernetes/issues/83332

标签： kubernetes metrics-server hpa

【解决方案1】：

我已经复制了您的问题（Google Compute Engine）。尝试了一些方案来找到此问题的解决方法/解决方案。

首先我要提到的是，您提供了ServiceAccount 和Deployment YAML。您还需要ClusterRoleBinding、RoleBinding、ApiService 等。所有需要的 YAML 都可以在 this Github repo 中找到。

为了快速部署metrics-server，您可以使用所有必需的配置：

$ git clone https://github.com/kubernetes-sigs/metrics-server.git
$ cd metrics-server/deploy/
$ kubectl apply -f kubernetes/
clusterrole.rbac.authorization.k8s.io/system:aggregated-metrics-reader created
clusterrolebinding.rbac.authorization.k8s.io/metrics-server:system:auth-delegator created
rolebinding.rbac.authorization.k8s.io/metrics-server-auth-reader created
apiservice.apiregistration.k8s.io/v1beta1.metrics.k8s.io created
serviceaccount/metrics-server created
deployment.apps/metrics-server created
service/metrics-server created
clusterrole.rbac.authorization.k8s.io/system:metrics-server created
clusterrolebinding.rbac.authorization.k8s.io/system:metrics-server created

我建议您检查您的 CNI pod（calico-node-d4rnh 和 calico-node-hawked）的第二件事。创建了 4h11m 但 Ready 0/1.

关于从 pod 和节点收集 CPU 和内存数据的最后一件事。

使用印花布

如果您使用一个节点kubeadm，它会正常工作，但是，当您在kubeadm 中使用多个节点时，这会导致一些问题。 Github 上有很多类似的主题。我在args: 中尝试了各种标志，但没有成功。在 metrics-server 日志 (-v=6) 中，您将能够看到正在收集的指标。在 this Github thread 中，一位 Github 用户发布了答案，这是解决此问题的方法。在K8s docs 中也提到了关于hostNetwork。

添加hostNetwork: true 最终让metrics-server 为我工作。没有它，纳达。如果没有kubelet-preferred-address-types line，我可以查询我的主节点，但不能查询我的两个工作节点，也不能查询 pod，这显然是不受欢迎的结果。缺少kubelet-insecure-tls 也会导致无法运行metrics-server 安装。

spec:
  hostNetwork: true
  containers:
  - args:
    - --kubelet-insecure-tls
    - --cert-dir=/tmp
    - --secure-port=4443
    - --kubelet-preferred-address-types=InternalIP
    - --v=6
    image: k8s.gcr.io/metrics-server-amd64:v0.3.6
    imagePullPolicy: Always

如果您将使用此配置进行部署，它将起作用。

$ kubectl describe apiservice v1beta1.metrics.k8s.io
Name:         v1beta1.metrics.k8s.io
...
Status:
  Conditions:
    Last Transition Time:  2020-02-20T09:37:59Z
    Message:               all checks passed
    Reason:                Passed
    Status:                True
    Type:                  Available
Events:                    <none>

另外，当你检查iptables时，你可以看到使用host network: true时的区别。与没有此配置的部署相比，条目要多得多。

之后，您可以编辑部署，删除或评论host network: true。

$ kubectl edit deploy metrics-server -n kube-system
deployment.apps/metrics-server edited

$ kubectl top pods
NAME                     CPU(cores)   MEMORY(bytes)   
nginx-6db489d4b7-2qhzw   0m           3Mi             
nginx-6db489d4b7-9fvrj   0m           2Mi             
nginx-6db489d4b7-dgbf9   0m           2Mi             
nginx-6db489d4b7-dvcz5   0m           2Mi

此外，您还可以使用以下方法查找指标：

$ kubectl get --raw /apis/metrics.k8s.io/v1beta1/nodes

为了获得更好的可见性，您还可以使用jq。

$ kubectl get --raw /apis/metrics.k8s.io/v1beta1/pods | jq .

使用编织网

当您将使用 Weave Net 而不是 Calico 时，它可以在不设置 host network 的情况下工作。

$ kubectl apply -f "https://cloud.weave.works/k8s/net?k8s-version=$(kubectl version | base64 | tr -d '\n')"

但是，您需要使用certificates。但是如果你不关心安全性，你可以像前面的例子一样使用--kubelet-insecure-tls，当Calico被使用时。

【讨论】：