如何使用 Minikube 加上 Busybox 驗證 Kubernetes 大全套整合 ELK、Prometheus 和 Grafana

嗨，各位技術同好們！今天我們要來探索一個超有趣的主題：如何在本地的 Minikube 上驗證 Kubernetes 的大全套整合，包括 ELK（Elasticsearch、Logstash 和 Kibana）、Prometheus 和 Grafana。這一切都會在一個方便的小環境裡進行，並且我們還會使用 Busybox 來協助驗證。準備好踏上這趟技術之旅了嗎？讓我們開始吧！

為什麼選擇 Minikube 和 Busybox？

首先，Minikube 是一個超棒的工具，能讓我們在本地環境中快速啟動一個完整的 Kubernetes 叢集。而 Busybox 是一個輕量級的 Linux 工具箱，內含了各種實用的命令，非常適合用來做各種測試和驗證。這兩個工具結合起來，簡直是本地開發和測試的黃金組合！

環境準備

在開始之前，我們需要確保已經安裝並配置好一些基礎工具：

  1. Minikube
  2. kubectl
  3. Helm
  4. Docker

安裝 Minikube

你可以使用 Homebrew 來安裝 Minikube：

brew install minikube

啟動 Minikube 並分配一些資源：

minikube start --memory 8192 --cpus 4

安裝 kubectl

同樣可以使用 Homebrew 來安裝 kubectl：

brew install kubectl

安裝 Helm

最後，使用 Homebrew 來安裝 Helm：

brew install helm

建立 Kubernetes 命名空間和持久化存儲

我們將為 ELK、Prometheus 和 Grafana 創建獨立的持久化存儲。以下是設定檔案 namespace-and-pv.yaml：

---
apiVersion: v1
kind: Namespace
metadata:
  name: monitoring

---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: elasticsearch-pv
spec:
  capacity:
    storage: 10Gi
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Retain
  storageClassName: local-storage
  local:
    path: "/mnt/data/elasticsearch"
  nodeAffinity:
    required:
      nodeSelectorTerms:
        - matchExpressions:
            - key: kubernetes.io/hostname
              operator: In
              values:
                - minikube

---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: elasticsearch-pvc
  namespace: monitoring
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 10Gi
  storageClassName: local-storage

---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: logstash-pv
spec:
  capacity:
    storage: 5Gi
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Retain
  storageClassName: local-storage
  local:
    path: "/mnt/data/logstash"
  nodeAffinity:
    required:
      nodeSelectorTerms:
        - matchExpressions:
            - key: kubernetes.io/hostname
              operator: In
              values:
                - minikube

---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: logstash-pvc
  namespace: monitoring
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 5Gi
  storageClassName: local-storage

---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: kibana-pv
spec:
  capacity:
    storage: 5Gi
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Retain
  storageClassName: local-storage
  local:
    path: "/mnt/data/kibana"
  nodeAffinity:
    required:
      nodeSelectorTerms:
        - matchExpressions:
            - key: kubernetes.io/hostname
              operator: In
              values:
                - minikube

---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: kibana-pvc
  namespace: monitoring
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 5Gi
  storageClassName: local-storage

---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: prometheus-pv
spec:
  capacity:
    storage: 10Gi
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Retain
  storageClassName: local-storage
  local:
    path: "/mnt/data/prometheus"
  nodeAffinity:
    required:
      nodeSelectorTerms:
        - matchExpressions:
            - key: kubernetes.io/hostname
              operator: In
              values:
                - minikube

---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: prometheus-pvc
  namespace: monitoring
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 10Gi
  storageClassName: local-storage

---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: grafana-pv
spec:
  capacity:
    storage: 5Gi
  accessModes:
    - ReadWriteOnce
  persistentVolumeReclaimPolicy: Retain
  storageClassName: local-storage
  local:
    path: "/mnt/data/grafana"
  nodeAffinity:
    required:
      nodeSelectorTerms:
        - matchExpressions:
            - key: kubernetes.io/hostname
              operator: In
              values:
                - minikube

---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: grafana-pvc
  namespace: monitoring
spec:
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 5Gi
  storageClassName: local-storage

應用這些設定：

kubectl apply -f namespace-and-pv.yaml

安裝 ELK、Prometheus 和 Grafana

1. 添加 Helm 仓库

helm repo add elastic https://helm.elastic.co
helm repo add prometheus-community https://prometheus-community.github.io/helm-charts
helm repo add grafana https://grafana.github.io/helm-charts
helm repo update

2. 安裝 Elasticsearch

創建一個 elasticsearch-values.yaml 文件：

volumeClaimTemplates:
  - metadata:
      name: elasticsearch-data
    spec:
      accessModes: [ "ReadWriteOnce" ]
      storageClassName: "local-storage"
      resources:
        requests:
          storage: 10Gi

安裝 Elasticsearch：

helm install elasticsearch elastic/elasticsearch --namespace monitoring -f elasticsearch-values.yaml

3. 安裝 Logstash

創建一個 logstash-values.yaml 文件：

logstashConfig:
  logstash.yml: |
    http.host: "0.0.0.0"
    xpack.monitoring.enabled: false    
  logstash.conf: |
    input {
      beats {
        port => 5044
      }
    }
    output {
      elasticsearch {
        hosts => ["http://elasticsearch-master:9200"]
      }
    }    
persistence:
  enabled: true
  existingClaim: logstash-pvc

安裝 Logstash：

helm install logstash elastic/logstash --namespace monitoring -f logstash-values.yaml

4. 安裝 Kibana

創建一個 kibana-values.yaml 文件：

persistence:
  enabled: true
  existingClaim: kibana-pvc

安裝 Kibana：

helm install kibana elastic/kibana --namespace monitoring -f kibana-values.yaml

5. 安裝

Prometheus

創建一個 prometheus-values.yaml 文件：

server:
  persistentVolume:
    existingClaim: prometheus-pvc

安裝 Prometheus：

helm install prometheus prometheus-community/prometheus --namespace monitoring -f prometheus-values.yaml

6. 安裝 Grafana

創建一個 grafana-values.yaml 文件：

datasources:
  datasources.yaml:
    apiVersion: 1
    datasources:
    - name: Prometheus
      type: prometheus
      url: http://prometheus-server.monitoring.svc.cluster.local
      access: proxy
      isDefault: true

persistence:
  enabled: true
  existingClaim: grafana-pvc

安裝 Grafana：

helm install grafana grafana/grafana --namespace monitoring -f grafana-values.yaml

驗證安裝

1. 驗證 Elasticsearch

kubectl get pods --namespace monitoring -l app=elasticsearch

2. 驗證 Logstash

kubectl get pods --namespace monitoring -l app=logstash

3. 驗證 Kibana

kubectl get pods --namespace monitoring -l app=kibana

4. 驗證 Prometheus

kubectl get pods --namespace monitoring -l app=prometheus

5. 驗證 Grafana

kubectl get pods --namespace monitoring -l app.kubernetes.io/name=grafana

訪問 Grafana 和 Kibana

訪問 Grafana

將 Grafana 服務暴露到本地端口：

kubectl port-forward svc/grafana 3000:80 --namespace monitoring

然後在瀏覽器中訪問 http://localhost:3000。

訪問 Kibana

將 Kibana 服務暴露到本地端口：

kubectl port-forward svc/kibana-kibana 5601:5601 --namespace monitoring

然後在瀏覽器中訪問 http://localhost:5601。

部署應用程序

以下是應用程序部署的示例配置文件 deployments.yaml：

---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: myapp
  namespace: default
spec:
  replicas: 2
  selector:
    matchLabels:
      app: myapp
  template:
    metadata:
      labels:
        app: myapp
    spec:
      containers:
        - name: myapp
          image: myapp:latest
          ports:
            - containerPort: 8080
---
apiVersion: v1
kind: Service
metadata:
  name: myapp-service
  namespace: default
spec:
  selector:
    app: myapp
  ports:
    - protocol: TCP
      port: 80
      targetPort: 8080

應用這些設定：

kubectl apply -f deployments.yaml

總結

通過本文，我們學會了如何使用 Minikube 和 Busybox 在本地環境中快速驗證 Kubernetes 的 ELK、Prometheus 和 Grafana 整合。我們一步步建立了命名空間和持久化存儲，並使用 Helm 安裝了所有需要的工具。希望這篇文章能幫助你在本地環境中更好地測試和開發 Kubernetes 應用。如果有任何問題或建議，歡迎在下方留言！

Happy Kubernetes-ing! 🚀