31 Mar 2021

01. 개요

Kubernetes-operator

https://kubernetes.io/ko/docs/concepts/extend-kubernetes/operator/
Operator는 특정 애플리케이션 컨트롤러 인 Kubernetes API를 확장하기 위해 회사에서 개발 한 CoreOS에 의해 생성됩니다 .
데이터베이스, 캐싱 및 모니터링 시스템과 같은 복잡한 상태 저장 애플리케이션을 생성, 구성 및 관리하는 데 사용됩니다.
Operator는 Kubernetes의 리소스 및 컨트롤러 개념을 기반으로하지만 일부 애플리케이션 별 전문 지식도 포함합니다.
예를 들어 데이터베이스 운영자를 생성하려면 생성 된 데이터베이스의 다양한 운영 및 유지 관리 방법에 매우 익숙해야합니다.
Operator를 만드는 열쇠는 CRD (custom resources)의 디자인입니다.
- https://github.com/prometheus-operator/kube-prometheus

ServiceMonitor

ServiceMonitor란 CRD(CustomResourceDefinition) 방식으로 Operator (코어OS 최초 시작)를 이용하여 Metric을 관리하는 방법 입니다.
Metric 추가 작업 시 prometheus.yml 파일에 manual하게 추가하는 것이 아니고 별도의 Kubernetes Object Servicemonitor (마치 configmap, deployment 처럼)를 이용합니다.
https://www.fatalerrors.org/a/rapid-deployment-of-kubernetes-monitoring-system-kube-prometheus.html

Summary

kube-prometheus-stack collects Kubernetes manifests, Grafana dashboards, and Prometheus rules combined with documentation and scripts to provide easy to operate end-to-end Kubernetes cluster monitoring with Prometheus using the Prometheus Operator.
Installs the kube-prometheus stack, a collection of Kubernetes manifests, Grafana dashboards, and Prometheus rules combined with documentation and scripts to provide easy to operate end-to-end Kubernetes cluster monitoring with Prometheus using the Prometheus Operator.

Dependencies

By default this chart installs additional, dependent charts:

Guide for kube-prometheus-stack with Helm3.x

https://artifacthub.io/packages/helm/prometheus-community/kube-prometheus-stack

02. 사전조건

Prerequisites

Kubernetes 1.16+
Helm 3+

Kubernetes Cluster 구성
kubectl 설치
Kubernetes Config
helm 설치

03. Namespace 생성

sansae@win10pro-worksp:$ kubectl create ns monitor-po

04. Install Chart of kube-prometheus-stack

sansae@win10pro-worksp:$ helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
"prometheus-community" already exists with the same configuration, skipping
sansae@win10pro-worksp:$
sansae@win10pro-worksp:$ helm repo update
Hang tight while we grab the latest from your chart repositories...
...Successfully got an update from the "ingress-nginx" chart repository
...Successfully got an update from the "elastic" chart repository
...Successfully got an update from the "dynatrace" chart repository
...Successfully got an update from the "prometheus-community" chart repository
Update Complete. ⎈Happy Helming!⎈
sansae@win10pro-worksp:$ helm install kube-prometheus-stack prometheus-community/kube-prometheus-stack -n monitor-po
NAME: kube-prometheus-stack
LAST DEPLOYED: Wed Mar 31 10:30:38 2021
NAMESPACE: monitor-po
STATUS: deployed
REVISION: 1
NOTES:
kube-prometheus-stack has been installed. Check its status by running:
  kubectl --namespace monitor-po get pods -l "release=kube-prometheus-stack"

Visit https://github.com/prometheus-operator/kube-prometheus for instructions on how to create & configure Alertmanager and Prometheus instances using the Operator.
sansae@win10pro-worksp:$ kubectl get all -n monitor-po
NAME                                                            READY   STATUS    RESTARTS   AGE
pod/alertmanager-kube-prometheus-stack-alertmanager-0           2/2     Running   0          91s
pod/kube-prometheus-stack-grafana-6b5c8fd86c-lwcv2              2/2     Running   0          93s
pod/kube-prometheus-stack-kube-state-metrics-7877f4cc7c-b2nnc   1/1     Running   0          93s
pod/kube-prometheus-stack-operator-5859b9c949-4n24x             1/1     Running   0          93s
pod/kube-prometheus-stack-prometheus-node-exporter-5f4pm        1/1     Running   0          93s
pod/kube-prometheus-stack-prometheus-node-exporter-5fbc7        1/1     Running   0          93s
pod/kube-prometheus-stack-prometheus-node-exporter-ggj8c        1/1     Running   0          93s
pod/kube-prometheus-stack-prometheus-node-exporter-h5cfj        1/1     Running   0          93s
pod/kube-prometheus-stack-prometheus-node-exporter-hvpsf        1/1     Running   0          93s
pod/kube-prometheus-stack-prometheus-node-exporter-mbt54        1/1     Running   0          93s
pod/kube-prometheus-stack-prometheus-node-exporter-s5zd9        1/1     Running   0          93s
pod/kube-prometheus-stack-prometheus-node-exporter-v7bsj        1/1     Running   0          93s
pod/kube-prometheus-stack-prometheus-node-exporter-v7sts        1/1     Running   0          93s
pod/kube-prometheus-stack-prometheus-node-exporter-vnmx5        1/1     Running   0          93s
pod/prometheus-kube-prometheus-stack-prometheus-0               2/2     Running   1          91s

NAME                                                     TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)
       AGE
service/alertmanager-operated                            ClusterIP   None           <none>        9093/TCP,9094/TCP,9094/UDP   91s
service/kube-prometheus-stack-alertmanager               ClusterIP   10.0.92.245    <none>        9093/TCP
       93s
service/kube-prometheus-stack-grafana                    ClusterIP   10.0.240.51    <none>        80/TCP
       93s
service/kube-prometheus-stack-kube-state-metrics         ClusterIP   10.0.47.252    <none>        8080/TCP
       93s
service/kube-prometheus-stack-operator                   ClusterIP   10.0.215.243   <none>        443/TCP
       93s
service/kube-prometheus-stack-prometheus                 ClusterIP   10.0.152.193   <none>        9090/TCP
       93s
service/kube-prometheus-stack-prometheus-node-exporter   ClusterIP   10.0.216.169   <none>        9100/TCP
       93s
service/prometheus-operated                              ClusterIP   None           <none>        9090/TCP
       91s

NAME                                                            DESIRED   CURRENT   READY   UP-TO-DATE   AVAILABLE   NODE SELECTOR   AGE
daemonset.apps/kube-prometheus-stack-prometheus-node-exporter   10        10        10      10           10          <none>          93s

NAME                                                       READY   UP-TO-DATE   AVAILABLE   AGE
deployment.apps/kube-prometheus-stack-grafana              1/1     1            1           93s
deployment.apps/kube-prometheus-stack-kube-state-metrics   1/1     1            1           93s
deployment.apps/kube-prometheus-stack-operator             1/1     1            1           93s

NAME                                                                  DESIRED   CURRENT   READY   AGE
replicaset.apps/kube-prometheus-stack-grafana-6b5c8fd86c              1         1         1       93s
replicaset.apps/kube-prometheus-stack-kube-state-metrics-7877f4cc7c   1         1         1       93s
replicaset.apps/kube-prometheus-stack-operator-5859b9c949             1         1         1       93s

NAME                                                               READY   AGE
statefulset.apps/alertmanager-kube-prometheus-stack-alertmanager   1/1     91s
statefulset.apps/prometheus-kube-prometheus-stack-prometheus       1/1     91s
sansae@win10pro-worksp:$

05. Volume 설정

05-01. StorageClass 확인

Prometheus Stacks에서 사용가능한 StorageClass는 AzureDisk이므로 'default 또는 managed-premium'을 사용해야 합니다.

sansae@win10pro-worksp:/workspaces$ kubectl get sc
NAME                PROVISIONER                RECLAIMPOLICY   VOLUMEBINDINGMODE      ALLOWVOLUMEEXPANSION   AGE
azurefile           kubernetes.io/azure-file   Delete          Immediate              true                   65d
azurefile-premium   kubernetes.io/azure-file   Delete          Immediate              true                   65d
default (default)   kubernetes.io/azure-disk   Delete          Immediate              true                   65d
managed             kubernetes.io/azure-disk   Delete          WaitForFirstConsumer   true                   30d
managed-premium     kubernetes.io/azure-disk   Delete          Immediate              true                   65d

05-02. Prometheus Volume

Prometheus의 storage에 storageClassName: managed-premium를 추가 합니다.
storage 사이즈도 프로젝트스펙에 맞게 적절하게 수정 합니다.

sansae@win10pro-worksp:/workspaces$ kubectl get prometheus -n monitor-pga
NAME                               VERSION   REPLICAS   AGE
kube-prometheus-stack-prometheus   v2.24.0   1          6d3h


sansae@win10pro-worksp:/workspaces$ kubectl edit prometheus kube-prometheus-stack-prometheus -n monitor-po
=============================================================
156   storage:
157     volumeClaimTemplate:
158       spec:
159         accessModes:
160         - ReadWriteOnce
161         resources:
162           requests:
163             storage: 50Gi
164         storageClassName: managed-premium
=============================================================

prometheus.monitoring.coreos.com/kube-prometheus-stack-prometheus edited


sansae@win10pro-worksp:/workspaces$ kubectl get pvc -n monitor-po
NAME                                                                                                   STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS      AGE
prometheus-kube-prometheus-stack-prometheus-db-prometheus-kube-prometheus-stack-prometheus-0           Bound    pvc-64f88c7f-6fad-4d66-b6eb-xxxxxxxxx   50Gi       RWO            managed-premium   6d2h

05-03. Alertmanager Volume

Alertmanager의 storage에 storageClassName: managed-premium를 추가 합니다.
storage 사이즈도 프로젝트스펙에 맞게 적절하게 수정 합니다.

sansae@win10pro-worksp:/workspaces$ kubectl get alertmanager -n monitor-po
NAME                                 VERSION   REPLICAS   AGE
kube-prometheus-stack-alertmanager   v0.21.0   1          6d3h


sansae@win10pro-worksp:/workspaces$ kubectl edit alertmanager kube-prometheus-stack-alertmanager -n monitor-po
=============================================================
  storage:
    volumeClaimTemplate:
      spec:
        accessModes:
        - ReadWriteOnce
        resources:
          requests:
            storage: 2Gi
        storageClassName: managed-premium
=============================================================
alertmanager.monitoring.coreos.com/kube-prometheus-stack-alertmanager edited


sansae@win10pro-worksp:/workspaces$ kubectl get pvc -n monitor-po
NAME                                                                                                   STATUS   VOLUME                                     CAPACITY   ACCESS MODES   STORAGECLASS      AGE
alertmanager-kube-prometheus-stack-alertmanager-db-alertmanager-kube-prometheus-stack-alertmanager-0   Bound    pvc-5e7b02eb-7109-417d-9c14-xxxxxxxx   2Gi        RWO            managed-premium   6d2h

05-04. Grafana Volume

Grafana는 Prometheus-operator로 구성된 리소스가 아닙니다.
따라서, PVC를 수동으로 생성하고, Deployment에 PVC를 사용하도록 수정해 줍니다.

sansae@win10pro-worksp:/workspaces$ vim grafana-pvc.yaml
=============================================================
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: grafana-pv-claim
  labels:
    app: grafana
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 1Gi
  storageClassName: managed-premium
=============================================================
sansae@win10pro-worksp:/workspaces$ kubectl create -f grafana-pvc.yaml
create pvc!!!



sansae@win10pro-worksp:/workspaces$ kubectl get deploy -n monitor-pga
NAME                                       READY   UP-TO-DATE   AVAILABLE   AGE
kube-prometheus-stack-grafana              1/1     1            1           6d3h


sansae@win10pro-worksp:/workspaces$ kubectl edit deploy kube-prometheus-stack-grafana -n monitor-po
=============================================================
       volumeMounts:
       - mountPath: /var/lib/grafana
         name: grafana-persistent-storage
-------------------------------------------------------
       volumes:
       - name: grafana-persistent-storage
         persistentVolumeClaim:
           claimName: grafana-pv-claim
=============================================================
deployment.apps/kube-prometheus-stack-grafana edited


sansae@win10pro-worksp:/workspaces$ kubectl get pvc -n monitor-po
NAME                  STATUS   VOLUME                                 CAPACITY   ACCESS MODES   STORAGECLASS      AGE
grafana-pv-claim      Bound    pvc-a13463fa-ebda-4632-a9c0-xxxxxxxx   1Gi        RWO            managed-premium   6d2h

06. Service Connection

06-01. Prometheus Operated

sansae@win10pro-worksp:$ kubectl get svc -n monitor-po
NAME                                             TYPE        CLUSTER-IP     EXTERNAL-IP   PORT(S)                      AGE
alertmanager-operated                            ClusterIP   None           <none>        9093/TCP,9094/TCP,9094/UDP   30m
kube-prometheus-stack-alertmanager               ClusterIP   10.0.92.245    <none>        9093/TCP                     30m
kube-prometheus-stack-grafana                    ClusterIP   10.0.240.51    <none>        80/TCP                       30m
kube-prometheus-stack-kube-state-metrics         ClusterIP   10.0.47.252    <none>        8080/TCP                     30m
kube-prometheus-stack-operator                   ClusterIP   10.0.215.243   <none>        443/TCP                      30m
kube-prometheus-stack-prometheus                 ClusterIP   10.0.152.193   <none>        9090/TCP                     30m
kube-prometheus-stack-prometheus-node-exporter   ClusterIP   10.0.216.169   <none>        9100/TCP                     30m
prometheus-operated                              ClusterIP   None           <none>        9090/TCP                     30m

sansae@win10pro-worksp:$ kubectl port-forward service/prometheus-operated 9090 -n monitor-po
Forwarding from 127.0.0.1:9090 -> 9090
Forwarding from [::1]:9090 -> 9090

06-02. Grafana

sansae@win10pro-worksp:$ kubectl port-forward service/kube-prometheus-stack-grafana 8000:80 -n monitor-po
Forwarding from 127.0.0.1:8000 -> 3000
Forwarding from [::1]:8000 -> 3000
Handling connection for 8000

default user/password is admin/prom-operator

06-03. AlertManager

sansae@win10pro-worksp:$ kubectl port-forward service/kube-prometheus-stack-alertmanager 9093:9093 -n monitor-po
Forwarding from 127.0.0.1:9093 -> 9093
Forwarding from [::1]:9093 -> 9093

참고: 삭제할 경우 namespace이외에 삭제 해야할 리소스

for n in $(kubectl get namespaces -o jsonpath={..metadata.name}); do
  kubectl delete --all --namespace=$n prometheus,servicemonitor,podmonitor,alertmanager
done

kubectl delete crd alertmanagerconfigs.monitoring.coreos.com
kubectl delete crd alertmanagers.monitoring.coreos.com
kubectl delete crd podmonitors.monitoring.coreos.com
kubectl delete crd probes.monitoring.coreos.com
kubectl delete crd prometheuses.monitoring.coreos.com
kubectl delete crd prometheusrules.monitoring.coreos.com
kubectl delete crd servicemonitors.monitoring.coreos.com
kubectl delete crd thanosrulers.monitoring.coreos.com

kubectl delete clusterrole kube-prometheus-stack-grafana-clusterrole
kubectl delete clusterrole kube-prometheus-stack-kube-state-metrics
kubectl delete clusterrole kube-prometheus-stack-operator
kubectl delete clusterrole kube-prometheus-stack-operator-psp
kubectl delete clusterrole kube-prometheus-stack-prometheus
kubectl delete clusterrole kube-prometheus-stack-prometheus-psp
kubectl delete clusterrole psp-kube-prometheus-stack-kube-state-metrics
kubectl delete clusterrole psp-kube-prometheus-stack-prometheus-node-exporter

kubectl delete clusterrolebinding kube-prometheus-stack-grafana-clusterrolebinding
kubectl delete clusterrolebinding kube-prometheus-stack-kube-state-metrics
kubectl delete clusterrolebinding kube-prometheus-stack-operator
kubectl delete clusterrolebinding kube-prometheus-stack-operator-psp
kubectl delete clusterrolebinding kube-prometheus-stack-prometheus
kubectl delete clusterrolebinding kube-prometheus-stack-prometheus-psp
kubectl delete clusterrolebinding psp-kube-prometheus-stack-kube-state-metrics
kubectl delete clusterrolebinding psp-kube-prometheus-stack-prometheus-node-exporter

kubectl delete svc kube-prometheus-stack-coredns -n kube-system
kubectl delete svc kube-prometheus-stack-kube-controller-manager -n kube-system
kubectl delete svc kube-prometheus-stack-kube-etcd -n kube-system
kubectl delete svc kube-prometheus-stack-kube-proxy -n kube-system
kubectl delete svc kube-prometheus-stack-kube-scheduler -n kube-system
kubectl delete svc kube-prometheus-stack-kubelet -n kube-system
kubectl delete svc prometheus-kube-prometheus-kubelet -n kube-system

kubectl delete MutatingWebhookConfiguration kube-prometheus-stack-admission
kubectl delete ValidatingWebhookConfiguration kube-prometheus-stack-admission