# monitor

* [prometheus](#prometheus)
  * [prometheus architecture](#prometheus-architecture)
* [grafana](#grafana)
  * [environment](#environment)
  * [setup](#setup)
  * [dashboard](#dashboard)
  * [grafana settings](#grafana-settings)
  * [api](#api)
* [add-ons](#add-ons)
* [metric server](#metric-server)
  * [sample yaml](#sample-yaml)
  * [q\&a](#qa)
* [kube-state-metrics](#kube-state-metrics)
  * [installation](#installation)
* [scripts](#scripts)
  * [node resources](#node-resources)

> \[!NOTE|label:references]
>
> * [MONITORING LINUX HOST METRICS WITH THE NODE EXPORTER](https://prometheus.io/docs/guides/node-exporter/)
> * [Kubernetes Resources(四) - Metrics Server 安裝](https://ithelp.ithome.com.tw/articles/10297449)
> * [Prometheus 5 - Node Exporter & Kube State Metrics](https://ithelp.ithome.com.tw/articles/10225912)
> * [kube-state-metrics | Tutorial, Setup, and Examples](https://www.containiq.com/post/kube-state-metrics)
> * [Installing Kubernetes Metric Server](https://docs.apinizer.com/installing-kubernetes-metric-server-16810589.html)
> * [Part-1: Setup Prometheus, Kube State metrics and Integrate Grafana with Kubernetes](https://blog.devops.dev/part-1-setup-prometheus-kube-state-metrics-and-integrate-grafana-with-kubernetes-6c21f60d167f)
> * [K8s资源限制设置limit未设置request会导致request默认等于limit造成资源浪费](https://github.com/Ouyangan/coding-roadmap/issues/16)
> * [\* How to Setup Prometheus Monitoring On Kubernetes Cluster](https://devopscube.com/setup-prometheus-monitoring-on-kubernetes/)
>
> code pool
>
> * [kubeless/manifests/monitoring](https://github.com/kubeless/kubeless/tree/master/manifests/monitoring)
> * [kube-prometheus/manifests](https://github.com/coreos/kube-prometheus/tree/master/manifests)
> * [kubernetes-handbook/manifests/prometheus](https://github.com/rootsongjc/kubernetes-handbook/tree/master/manifests/prometheus)

### prometheus

> \[!NOTE|label:references:]
>
> * [#973 - \[prometheus-kube-stack\] Prometheus ingress is missing pathType](https://github.com/prometheus-community/helm-charts/issues/973)
> * [Setting Up Kube-Prometheus-Stack on Kubernetes Services](https://srivastavasuman8.medium.com/setting-up-kube-prometheus-stack-on-kubernetes-services-5acc10fbb535)
> * [charts/kube-prometheus-stack/templates/prometheus/ingress.yaml](https://github.com/prometheus-community/helm-charts/blob/main/charts/kube-prometheus-stack/templates/prometheus/ingress.yaml)

#### [prometheus architecture](https://blog.codefarm.me/2020/02/10/kubernetes-crash-course-6/)

![prometheus architecture](https://1999659500-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MHqOSW6on5cHbtwcSH6%2Fuploads%2Fgit-blob-1610bc02435fafceadb979baffceb026ed17b2f0%2Fprometheus-architecture.png?alt=media)

### grafana

{% hint style="info" %}

> references:
>
> * [\* play.grafana.org](https://play.grafana.org/)
> * [\* Setting Up Kubernetes Dashboard](https://www.youtube.com/watch?v=aB0TagEzTAw)
> * [\* Deploy Grafana Enterprise on Kubernetes](https://grafana.com/docs/grafana/latest/installation/kubernetes/#deploy-grafana-enterprise-on-kubernetes)
> * [\* Deploy Grafana on Kubernetes](https://grafana.com/docs/grafana/latest/installation/kubernetes/)
> * [\* Kubernetes Integration](https://grafana.com/docs/grafana-cloud/kubernetes/integration-kubernetes/?pg=blog\&plcmt=body-txt)
> * [\* Install plugin from dockerfile](https://community.grafana.com/t/install-plugin-from-dockerfile/2603/5)
> * [\* grafana/grafana-docker](https://github.com/grafana/grafana-docker/blob/master/Dockerfile)
> * [Scaling out Grafana with Kubernetes and AWS](https://medium.com/@fcgravalos/scaling-out-grafana-with-kubernetes-and-aws-62745257df10)
> * [Monitoring Kubernetes Clusters with Grafana](https://medium.com/htc-research-engineering-blog/monitoring-kubernetes-clusters-with-grafana-e2a413febefd)
> * [Configure a Grafana Docker image](https://grafana.com/docs/grafana/latest/administration/configure-docker/)
> * [Configure Grafana](https://grafana.com/docs/grafana/next/setup-grafana/configure-grafana/#configure-with-environment-variables)
> * [Grafana 6.2 documentation : Installing using Docker](https://www.bookstack.cn/read/grafana-v6.2/f54c77073729e6c9.md)
> * [Restart Grafana](https://grafana.com/docs/grafana/latest/installation/restart-grafana/)
> * [Grafana Loki Concise Tutorial](https://www.sobyte.net/post/2021-10/grafana-loki-usage/)
> * [Grafana CLI](https://grafana.com/docs/grafana/latest/administration/cli)
> * [\* Prometheus data source](https://grafana.com/docs/grafana/latest/datasources/prometheus/)
> * [\* GRAFANA SUPPORT FOR PROMETHEUS](https://prometheus.io/docs/visualization/grafana/)
> * [\* Create Grafana Dashboards with Prometheus Metrics](https://www.programmingwithwolfgang.com/create-grafana-dashboards-with-prometheus-metrics)
>
> how to: - \[How To Setup Grafana On Kubernetes]\(<https://devopscube.com/setup-grafana-kubernetes/>) - \[How To Setup Kube State Metrics on Kubernetes]\(<https://devopscube.com/setup-kube-state-metrics/>)
> {% endhint %}

#### environment

> \[!TIP]
>
> * [reference](https://grafana.com/docs/grafana/next/setup-grafana/configure-grafana/#override-configuration-with-environment-variables) Do not use environment variables to add new configuration settings. Instead, use environmental variables to override existing options.
>
> To override an option: \`\`\`bash GF\_\_ \`\`\`
>
> If you need to specify the version of a plugin, then you can add it to the \`GF\_INSTALL\_PLUGINS\` environment variable. Otherwise, the latest is used. For example: \`\`\`bash -e "GF\_INSTALL\_PLUGINS=grafana-clock-panel 1.0.1,grafana-simple-json-datasource 1.3.5" \`\`\`

```bash
# for pvc
kubems-01 ~ $ mkdir -p /opt/grafana/plugins
kubems-01 ~ $ sudo chown -R 472:472 $_

# https://grafana.com/docs/grafana/latest/installation/docker/#migration-from-a-previous-version-of-the-docker-container-to-5-1-or-later
# 104:104 for version < 5.1
```

* [user id changes](https://grafana.com/docs/grafana/latest/installation/docker/#user-id-changes)

  |  Version |   User  | User ID |
  | :------: | :-----: | :-----: |
  |  `< 5.1` | grafana |  `104`  |
  | `>= 5.1` | grafana |  `472`  |
* path

  | SETTING                 | DEFAULT VALUE               |
  | ----------------------- | --------------------------- |
  | `GF_PATHS_CONFIG`       | `/etc/grafana/grafana.ini`  |
  | `GF_PATHS_DATA`         | `/var/lib/grafana`          |
  | `GF_PATHS_HOME`         | `/usr/share/grafana`        |
  | `GF_PATHS_LOGS`         | `/var/log/grafana`          |
  | `GF_PATHS_PLUGINS`      | `/var/lib/grafana/plugins`  |
  | `GF_PATHS_PROVISIONING` | `/etc/grafana/provisioning` |
* environment

  | ENVIRONMENT VARIABLE         | EXAMPLE                                                                  |
  | ---------------------------- | ------------------------------------------------------------------------ |
  | `GF_INSTALL_PLUGINS`         | `grafana-kubernetes-app,grafana-piechart-panel,http://my.com/plugin.zip` |
  | `GF_PATHS_PLUGINS`           | `/data/grafana/plugins`                                                  |
  | `GF_SERVER_ROOT_URL`         | `https://grafana.domain.com`                                             |
  | `GF_SECURITY_ADMIN_PASSWORD` | `admin`                                                                  |
  | `GF_DEFAULT_INSTANCE_NAME`   | -                                                                        |
  | `GF_SECURITY_ADMIN_USER`     | -                                                                        |
  | `GF_DATABASE_TYPE`           | `mysql`                                                                  |
  | `GF_DATABASE_HOST`           | -                                                                        |

#### setup

* ns

  ```bash
  $ cat << EOF | kubectl apply -f -
  ---
  kind: Namespace
  apiVersion: v1
  metadata:
    name: kubernetes-dashboard
    labels:
      name: kubernetes-dashboard
  EOF
  ```
* sa

  ```bash
  $ cat << EOF | kubectl apply -f -
  ---
  apiVersion: v1
  kind: ServiceAccount
  metadata:
    labels:
      k8s-app: grafana
    name: grafana-admin
    namespace: kubernetes-dashboard
  ---
  apiVersion: rbac.authorization.k8s.io/v1beta1
  kind: ClusterRoleBinding
  metadata:
    name: grafana-admin
    labels:
      k8s-app: grafana
  roleRef:
    apiGroup: rbac.authorization.k8s.io
    kind: ClusterRole
    name: cluster-admin
  subjects:
  - kind: ServiceAccount
    name: grafana
    namespace: kubernetes-dashboard
  EOF
  ```
* pv & pvc

  ```bash
  $ cat << EOF | kubectl apply -f -
  ---
  kind: PersistentVolume
  apiVersion: v1
  metadata:
    name: grafana
    labels:
      type: local
  spec:
    storageClassName: manual
    capacity:
      storage: 2Gi
    accessModes:
      - ReadWriteMany
    hostPath:
      path: "/opt/grafana"
  ---
  kind: PersistentVolumeClaim
  apiVersion: v1
  metadata:
    name: grafana
    namespace: kubernetes-dashboard
  spec:
    accessModes:
    - ReadWriteMany
    resources:
      requests:
        storage: 2Gi
    storageClassName: "manual"
    volumeName: grafana
  EOF
  ```
* deploy

  ```bash
  $ cat << EOF | kubectl apply -f -
  ---
  apiVersion: extensions/v1beta1
  kind: Deployment
  metadata:
    name: grafana
    namespace: kubernetes-dashboard
    labels:
      app: grafana
      component: core
  spec:
    replicas: 1
    strategy:
      rollingUpdate:
        maxSurge: 25%
        maxUnavailable: 25%
      type: RollingUpdate
    template:
      metadata:
        labels:
          app: grafana
          component: core
      spec:
        affinity:
          nodeAffinity:
            requiredDuringSchedulingIgnoredDuringExecution:
              nodeSelectorTerms:
              - matchExpressions:
                - key: kubernetes.io/hostname
                  operator: In
                  values:
                  - kubems-01
        containers:
        - image: grafana/grafana
          name: grafana
          imagePullPolicy: IfNotPresent
          resources:
            # keep request = limit to keep this container in guaranteed class
            limits:
              cpu: 512m
              memory: 512Mi
            requests:
              cpu: 256m
              memory: 256Mi
          env:
            # The following env variables set up basic auth twith the default admin user and admin password.
            - name: GF_SERVER_DOMAIN
              value: "grafana.marslo.com"
            - name: GF_SECURITY_ADMIN_PASSWORD
              value: "mypasswd"
            - name: GF_INSTALL_PLUGINS
              value: "grafana-kubernetes-app"
            - name: GF_SERVER_ROOT_URL
              value: "/"
            - name: GF_AUTH_BASIC_ENABLED
              value: "true"
            - name: GF_AUTH_ANONYMOUS_ENABLED
              value: "false"
          readinessProbe:
            httpGet:
              path: /login
              port: 3000
          volumeMounts:
          - name: grafana-persistent-storage
            mountPath: /var/lib/grafana
        restartPolicy: Always
        terminationGracePeriodSeconds: 30
        serviceAccountName: grafana
        volumes:
        - name: grafana-persistent-storage
          persistentVolumeClaim:
            claimName: grafana
  EOF
  ```
* svc

  ```bash
  $ cat << EOF | kubectl apply -f -
  ---
  apiVersion: v1
  kind: Service
  metadata:
    name: grafana
    namespace: kubernetes-dashboard
    labels:
      app: grafana
      component: core
  spec:
    type: CluslterIP
    ports:
      - name: http
        port: 3000
        protocol: TCP
    selector:
      app: grafana
      component: core
  EOF
  ```
* ingress

  ```bash
  $ cat << EOF | kubectl apply -f -
  apiVersion: extensions/v1beta1
  kind: Ingress
  metadata:
    name: grafana
    namespace: kubernetes-dashboard
  spec:
    rules:
    - host: grafana.marslo.com
     http:
       paths:
       - path: /
         backend:
          serviceName: grafana
          servicePort: http
    tls:
    - hosts:
      - grafana.marslo.com
      secretName: marslo-cert
  EOF
  ```

#### dashboard

> \[!NOTE|label:references:]
>
> * [nodejs/eks/dashboard/kubernetes-dashboard.yaml](https://github.com/pulumi/pulumi-eks/blob/master/nodejs/eks/dashboard/kubernetes-dashboard.yaml)

**kubernetes cluster monitoring**

* [devopsprodigy-kubegraf-app](https://grafana.com/grafana/plugins/devopsprodigy-kubegraf-app/)
  * install via `grafana-cli`

    ```bash
    $ grafana-cli plugins install devopsprodigy-kubegraf-app
    ```
  * setup sa and cluster role

    ```bash
    $ kubectl create ns kubegraf
    $ kubectl apply -f https://raw.githubusercontent.com/devopsprodigy/kubegraf/master/kubernetes/serviceaccount.yaml
    $ kubectl apply -f https://raw.githubusercontent.com/devopsprodigy/kubegraf/master/kubernetes/clusterrole.yaml
    $ kubectl apply -f https://raw.githubusercontent.com/devopsprodigy/kubegraf/master/kubernetes/clusterrolebinding.yaml
    $ kubectl apply -f https://raw.githubusercontent.com/devopsprodigy/kubegraf/master/kubernetes/secret.yaml
    ```
  * create private certificate

{% hint style="info" %}

```
copy `/etc/kubernetes/pki/grafana-kubegraf.crt` to all masters
```

{% endhint %}

````
```bash
$ openssl genrsa -out ~/grafana-kubegraf.key 2048
$ openssl req -new -key ~/grafana-kubegraf.key -out ~/grafana-kubegraf.csr -subj "/CN=grafana-kubegraf/O=monitoring"
$ openssl x509 -req -in ~/grafana-kubegraf.csr -CA /etc/kubernetes/pki/ca.crt -CAkey /etc/kubernetes/pki/ca.key -out /etc/kubernetes/pki/grafana-kubegraf.crt -CAcreateserial
```
- get token
  ```bash
  $ kubectl get secret grafana-kubegraf-secret -o jsonpath={.data.token} -n kubegraf | base64 -d
  ```
````

* [grafana-kubernetes-app](https://grafana.com/grafana/plugins/grafana-kubernetes-app/)

{% hint style="info" %}
@deprecated
{% endhint %}

* install via `grafana-cli`

  ```bash
  $ grafana-cli plugins install kubernetes-app
  ```
* setup

  ```bash
  $ cat ~/.kube/config | grep certificate-authority-data | awk '{print $2}' | base64 -d
  $ cat ~/.kube/config | grep client-certificate-data | awk '{print $2}' | base64 -d
  $ cat ~/.kube/config | grep client-key-data | awk '{print $2}' | base64 -d
  ```

![grafana-plugin-1.gif](https://1999659500-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MHqOSW6on5cHbtwcSH6%2Fuploads%2Fgit-blob-e826d97eabe8d491931ed2595dc3ddb8a21b2f09%2Fgrafana-plugin-1.gif?alt=media)

{% hint style="info" %}

> references:
>
> * [Dashboards](https://grafana.com/grafana/dashboards/)
> * [Monitor Kubernetes easily with Grafana](https://grafana.com/solutions/kubernetes/monitor/?pg=dashboards\&plcmt=featured-dashboard-1)
> * [Export and import](https://grafana.com/docs/grafana/v7.5/dashboards/export-import/#export-and-import)
> * [Create Grafana Dashboards with Prometheus Metrics](https://www.programmingwithwolfgang.com/create-grafana-dashboards-with-prometheus-metrics)
>   {% endhint %}

**cluster**

* [\*`315` - Kubernetes cluster monitoring (via Prometheus)](https://grafana.com/grafana/dashboards/315-kubernetes-cluster-monitoring-via-prometheus/)

  ![grafana-315.gif](https://1999659500-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F-MHqOSW6on5cHbtwcSH6%2Fuploads%2Fgit-blob-62d723b33e2958533d0d2d6d75936dfe0249f9f9%2Fgrafana-315.gif?alt=media)
* [\*`8588` - Kubernetes Deployment Statefulset Daemonset metrics](https://grafana.com/grafana/dashboards/8588)
* [`6417` - Kubernetes Cluster (Prometheus)](https://grafana.com/grafana/dashboards/6417)
* [`3662` - Prometheus 2.0 Overview](https://grafana.com/grafana/dashboards/3662)

**node**

* [\*`1860` - Node Exporter Full](https://grafana.com/grafana/dashboards/1860)
* [\*`6287` - Host Overview](https://grafana.com/grafana/dashboards/6287)
* [\*`10242` - Node Exporter Full with Node Name](https://grafana.com/grafana/dashboards/10242)

**namespace**

* [\*`9809` - Kubernetes Namespace Resources](https://grafana.com/grafana/dashboards/9809)

**pod**

* [\*`747` - Kubernetes Pod Metrics](https://grafana.com/grafana/dashboards/747)
* [\*`6336` - Kubernetes Pods](https://grafana.com/grafana/dashboards/6336)

**jenkins**

* [`9524` - a Jenkins performance and health overview for jenkinsci/prometheus-plugin](https://grafana.com/grafana/dashboards/9524)
* [`9964` - Jenkins: Performance and Health Overview](https://grafana.com/grafana/dashboards/9964)

#### grafana settings

* cluster

  ```
  label_values(kube_pod_info, cluster)
  ```

  * or

    ```
    label_values(node_cpu_seconds_total, cluster)
    ```
* instance

  ```
  label_values(apiserver_request_total{job="apiserver"}, instance)
  ```
* node

  ```
  label_values(kube_node_info{cluster="$cluster"}, node)
  ```

  * or

    ```
    label_values(kubernetes_io_hostname)
    ```
* namespace

  ```
  label_values(kube_pod_info{cluster="$cluster"}, namespace)
  ```
* pod

  ```
  label_values(kube_pod_info{cluster="$cluster", namespace="$namespace"}, pod)
  ```

#### api

> references:
>
> * [Grafana Docker and data persistence](https://community.grafana.com/t/grafana-docker-and-data-persistence/33702/2)

[**reset password**](https://grafana.com/docs/grafana/latest/administration/cli/)

```bash
$ curl -X PUT -H "Content-Type: application/json" -d '{
  "oldPassword": "admin",
  "newPassword": "newpass",
  "confirmNew": "newpass"
}' http://admin:admin@<your_grafana_host>:3000/api/user/password
```

**set grafana admin password**

```bash
$ docker exec -t grafana \
              bash -c 'grafana-cli --homepath /usr/share/grafana admin reset-admin-password "{{ grafana_passwd }}"'
```

**check if grafana can be accessed**

```bash
$ curl -s http://localhost:3000/api/org \
       -u {{ grafana_user }}:{{ grafana_passwd }}
```

**create datasoure in grafana**

```bash
$ curl -L \
       --header 'Content-Type: application/json' \
       --header 'Accept: application/json' \
       -d@//docker_data/grafana_conf/grafanacfg.output http://localhost:3000/api/datasources \
       -u {{ grafana_user }}:{{ grafana_passwd }}
```

**create TelegrafHost dashboard in grafana using jsonfile**

```bash
$ curl -L \
       --header 'Content-Type: application/json' \
       --header 'Accept: application/json' \
       -d@/home/Configfiles/dashboards/TelegrafHostMetrics.json http://localhost:3000/api/dashboards/db \
       -u {{ grafana_user }}:{{ grafana_passwd }}
```

**create DockerMetrics dashboard in grafana using jsonfile**

```bash
$ curl --header 'Content-Type: application/json' \
       --header 'Accept: application/json' \
       -d@/home/Configfiles/dashboards/DockerMetricsperContainer.json http://localhost:3000/api/dashboards/db \
       -u {{ grafana_user }}:{{ grafana_passwd }}
```

**create JVM dashboard in grafana using jsonfile**

```bash
$ curl --header 'Content-Type: application/json' \
       --header 'Accept: application/json' \
       -d@/home/Configfiles/dashboards/jvm-metrics-jolokia-2_rev1.json http://localhost:3000/api/dashboards/db \
       -u {{ grafana_user }}:{{ grafana_passwd }}
```

### add-ons

* [kube-state-metrics](https://github.com/kubernetes/kube-state-metrics)
* [node\_exporter](https://github.com/prometheus/node_exporter)
* [alertmanager](https://github.com/prometheus/alertmanager)
* [kube-resource-explorer](https://github.com/dpetzold/kube-resource-explorer/)

### metric server

> \[!NOTE|label:references:]
>
> * [kubernetes-sigs/metrics-server](https://github.com/kubernetes-sigs/metrics-server)
> * [metrics-server-deployment.yaml](https://github.com/kubernetes/kubernetes/blob/master/cluster/addons/metrics-server/metrics-server-deployment.yaml)
> * [Kubernetes metrics | Error from server (ServiceUnavailable) | Quick 2 fixes](https://www.linuxsysadmins.com/service-unavailable-kubernetes-metrics/)

#### sample yaml

```bash
apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    k8s-app: metrics-server
  name: metrics-server
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  labels:
    k8s-app: metrics-server
    rbac.authorization.k8s.io/aggregate-to-admin: "true"
    rbac.authorization.k8s.io/aggregate-to-edit: "true"
    rbac.authorization.k8s.io/aggregate-to-view: "true"
  name: system:aggregated-metrics-reader
rules:
- apiGroups:
  - metrics.k8s.io
  resources:
  - pods
  - nodes
  verbs:
  - get
  - list
  - watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  labels:
    k8s-app: metrics-server
  name: system:metrics-server
rules:
- apiGroups:
  - ""
  resources:
  - nodes/metrics
  verbs:
  - get
- apiGroups:
  - ""
  resources:
  - pods
  - nodes
  verbs:
  - get
  - list
  - watch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  labels:
    k8s-app: metrics-server
  name: metrics-server-auth-reader
  namespace: kube-system
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: extension-apiserver-authentication-reader
subjects:
- kind: ServiceAccount
  name: metrics-server
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  labels:
    k8s-app: metrics-server
  name: metrics-server:system:auth-delegator
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:auth-delegator
subjects:
- kind: ServiceAccount
  name: metrics-server
  namespace: kube-system
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  labels:
    k8s-app: metrics-server
  name: system:metrics-server
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: system:metrics-server
subjects:
- kind: ServiceAccount
  name: metrics-server
  namespace: kube-system
---
apiVersion: v1
kind: Service
metadata:
  labels:
    k8s-app: metrics-server
  name: metrics-server
  namespace: kube-system
spec:
  ports:
  - name: https
    port: 443
    protocol: TCP
    targetPort: https
  selector:
    k8s-app: metrics-server
---
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    k8s-app: metrics-server
  name: metrics-server
  namespace: kube-system
spec:
  selector:
    matchLabels:
      k8s-app: metrics-server
  strategy:
    rollingUpdate:
      maxUnavailable: 0
  template:
    metadata:
      labels:
        k8s-app: metrics-server
    spec:
      containers:
      - args:
        - --cert-dir=/tmp
        - --secure-port=4443
        - --kubelet-preferred-address-types=InternalIP,ExternalIP,Hostname
        - --kubelet-use-node-status-port
        - --kubelet-insecure-tls
        - --metric-resolution=15s
        image: registry.k8s.io/metrics-server/metrics-server:v0.6.3
        imagePullPolicy: IfNotPresent
        livenessProbe:
          failureThreshold: 3
          httpGet:
            path: /livez
            port: https
            scheme: HTTPS
          periodSeconds: 10
        name: metrics-server
        ports:
        - containerPort: 4443
          name: https
          protocol: TCP
        readinessProbe:
          failureThreshold: 3
          httpGet:
            path: /readyz
            port: https
            scheme: HTTPS
          initialDelaySeconds: 20
          periodSeconds: 10
        resources:
          requests:
            cpu: 100m
            memory: 200Mi
        securityContext:
          allowPrivilegeEscalation: false
          readOnlyRootFilesystem: true
          runAsNonRoot: true
          runAsUser: 1000
        volumeMounts:
        - mountPath: /tmp
          name: tmp-dir
      nodeSelector:
        kubernetes.io/os: linux
      priorityClassName: system-cluster-critical
      serviceAccountName: metrics-server
      volumes:
      - emptyDir: {}
        name: tmp-dir
---
apiVersion: apiregistration.k8s.io/v1
kind: APIService
metadata:
  labels:
    k8s-app: metrics-server
  name: v1beta1.metrics.k8s.io
spec:
  group: metrics.k8s.io
  groupPriorityMinimum: 100
  insecureSkipTLSVerify: true
  service:
    name: metrics-server
    namespace: kube-system
  version: v1beta1
  versionPriority: 100
```

#### q\&a

```bash
$ curl -k https://api.server.com:6443/api/v1/model/metrics/
{
  "kind": "Status",
  "apiVersion": "v1",
  "metadata": {

  },
  "status": "Failure",
  "message": "model \"metrics\" is forbidden: User \"system:anonymous\" cannot get resource \"model\" in API group \"\" at the cluster scope",
  "reason": "Forbidden",
  "details": {
    "name": "metrics",
    "kind": "model"
  },
  "code": 403
}

$ kubectl get --raw "/apis/metrics.k8s.io/v1beta1/pods"
Error from server (ServiceUnavailable): the server is currently unable to handle the request

$ kubectl top node
Error from server (ServiceUnavailable): the server is currently unable to handle the request (get nodes.metrics.k8s.io)

$ kubectl describe apiservice v1beta1.metrics.k8s.io
Name:         v1beta1.metrics.k8s.io
Namespace:
Labels:       k8s-app=metrics-server
Annotations:  kubectl.kubernetes.io/last-applied-configuration:
                {"apiVersion":"apiregistration.k8s.io/v1","kind":"APIService","metadata":{"annotations":{},"labels":{"k8s-app":"metrics-server"},"name":"v...
API Version:  apiregistration.k8s.io/v1
Kind:         APIService
Metadata:
  Creation Timestamp:  2023-05-10T03:35:06Z
  Resource Version:    404029923
  Self Link:           /apis/apiregistration.k8s.io/v1/apiservices/v1beta1.metrics.k8s.io
  UID:                 a7f6a96d-eee3-11ed-9c0f-b883034b82d0
Spec:
  Group:                     metrics.k8s.io
  Group Priority Minimum:    100
  Insecure Skip TLS Verify:  true
  Service:
    Name:            metrics-server
    Namespace:       kube-system
  Version:           v1beta1
  Version Priority:  100
Status:
  Conditions:
    Last Transition Time:  2023-05-10T03:35:06Z
    Message:               endpoints for service/metrics-server in "kube-system" have no addresses
    Reason:                MissingEndpoints
    Status:                False
    Type:                  Available
Events:                    <none>
```

### kube-state-metrics

> \[!INFO|label:references:]
>
> * [kube-state-metrics | Tutorial, Setup, and Examples](https://www.containiq.com/post/kube-state-metrics)
> * [kube-state-metrics Helm Chart](https://artifacthub.io/packages/helm/prometheus-community/kube-state-metrics)
> * [How To Setup Kube State Metrics on Kubernetes](https://devopscube.com/setup-kube-state-metrics/)

#### installation

```bash
$ helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
$ helm repo update
$ helm install kube-state-metrics prometheus-community/kube-state-metrics

# others
$ helm show values prometheus-community/kube-state-metrics
$ helm install -f config.yaml kube-state-metrics prometheus-community/kube-state-metrics

$ kubectl port-forward svc/kube-state-metrics 8080:8080
$ curl 127.0.0.1:8080/metrics | grep kube_node_status_capacity

# cost considerations
# values.yaml
metricAllowlist:
 - kube_node_info
 - kube_job_status_active
```

### scripts

#### [node resources](https://github.com/kubernetes/kubernetes/issues/17512#issuecomment-304069458)

```bash
$ cat bin/node-resources.sh
#!/bin/bash
set -euo pipefail

echo -e "Iterating...\n"

nodes=$(kubectl get node --no-headers -o custom-columns=NAME:.metadata.name)

for node in $nodes; do
  echo "Node: $node"
  kubectl describe node "$node" | sed '1,/Non-terminated Pods/d'
  echo
done
```

* one-line

  ```bash
  $ kubectl get nodes |
            awk '{print $1}' |
            xargs -I {} sh -c 'echo  {} ; kubectl describe node {} | grep Allocated -A 5 | grep -ve Event -ve Allocated -ve percent -ve -- ; echo '

  # alias
  $ alias util='kubectl get nodes | awk '\''{print $1}'\'' | xargs -I {} sh -c '\''echo   {} ; kubectl describe node {} | grep Allocated -A 5 | grep -ve Event -ve Allocated -ve percent -ve -- ; echo '\'''
  # or
  $ alias util='kubectl get nodes -o 'jsonpath={.items[*].metadata.name} | fmt -1 | xargs -I {} sh -c '\''echo   {} ; kubectl describe node {} | grep Allocated -A 5 | grep -ve Event -ve Allocated -ve percent -ve -- ; echo '\'''
  # or
  $ alias util='kubectl get no --no-headers -o=custom-columns=NAME:.metadata.name | xargs -I {} sh -c '\''echo   {} ; kubectl describe node {} | grep Allocated -A 5 | grep -ve Event -ve Allocated -ve percent -ve -- ; echo '\'''
  ```