（可选）为大型集群启用 Use_Kubelet 功能

默认情况下，在 FluentBit Kubernetes 插件中禁用 Use_Kubelet 功能。启用此功能可以减少 API 服务器的流量，并缓解 API 服务器成为瓶颈的问题。我们建议您为大型集群启用此功能。

要启用 Use_Kubelet，请先将节点和节点/代理权限添加到 clusterRole config 中。

apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: fluent-bit-role
rules:
  - nonResourceURLs:
      - /metrics
    verbs:
      - get
  - apiGroups: [""]
    resources:
      - namespaces
      - pods
      - pods/logs
      - nodes
      - nodes/proxy
    verbs: ["get", "list", "watch"]

在 DaemonSet 配置中，此功能需要主机网络访问权限。适用于 amazon/aws-for-fluent-bit 的镜像版本应为 2.12.0 或更高版本，或者 fluent bit 镜像版本应为 1.7.2 或更高版本。

apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: fluent-bit
  namespace: amazon-cloudwatch
  labels:
    k8s-app: fluent-bit
    version: v1
    kubernetes.io/cluster-service: "true"
spec:
  selector:
    matchLabels:
      k8s-app: fluent-bit
  template:
    metadata:
      labels:
        k8s-app: fluent-bit
        version: v1
        kubernetes.io/cluster-service: "true"
    spec:
      containers:
      - name: fluent-bit
        image: amazon/aws-for-fluent-bit:2.19.0
        imagePullPolicy: Always
        env:
            - name: AWS_REGION
              valueFrom:
                configMapKeyRef:
                  name: fluent-bit-cluster-info
                  key: logs.region
            - name: CLUSTER_NAME
              valueFrom:
                configMapKeyRef:
                  name: fluent-bit-cluster-info
                  key: cluster.name
            - name: HTTP_SERVER
              valueFrom:
                configMapKeyRef:
                  name: fluent-bit-cluster-info
                  key: http.server
            - name: HTTP_PORT
              valueFrom:
                configMapKeyRef:
                  name: fluent-bit-cluster-info
                  key: http.port
            - name: READ_FROM_HEAD
              valueFrom:
                configMapKeyRef:
                  name: fluent-bit-cluster-info
                  key: read.head
            - name: READ_FROM_TAIL
              valueFrom:
                configMapKeyRef:
                  name: fluent-bit-cluster-info
                  key: read.tail
            - name: HOST_NAME
              valueFrom:
                fieldRef:
                  fieldPath: spec.nodeName
            - name: HOSTNAME
              valueFrom:
                fieldRef:
                  apiVersion: v1
                  fieldPath: metadata.name      
            - name: CI_VERSION
              value: "k8s/1.3.8"
        resources:
            limits:
              memory: 200Mi
            requests:
              cpu: 500m
              memory: 100Mi
        volumeMounts:
        # Please don't change below read-only permissions
        - name: fluentbitstate
          mountPath: /var/fluent-bit/state
        - name: varlog
          mountPath: /var/log
          readOnly: true
        - name: varlibdockercontainers
          mountPath: /var/lib/docker/containers
          readOnly: true
        - name: fluent-bit-config
          mountPath: /fluent-bit/etc/
        - name: runlogjournal
          mountPath: /run/log/journal
          readOnly: true
        - name: dmesg
          mountPath: /var/log/dmesg
          readOnly: true
      terminationGracePeriodSeconds: 10
      hostNetwork: true
      dnsPolicy: ClusterFirstWithHostNet
      volumes:
      - name: fluentbitstate
        hostPath:
          path: /var/fluent-bit/state
      - name: varlog
        hostPath:
          path: /var/log
      - name: varlibdockercontainers
        hostPath:
          path: /var/lib/docker/containers
      - name: fluent-bit-config
        configMap:
          name: fluent-bit-config
      - name: runlogjournal
        hostPath:
          path: /run/log/journal
      - name: dmesg
        hostPath:
          path: /var/log/dmesg
      serviceAccountName: fluent-bit
      tolerations:
      - key: node-role.kubernetes.io/master
        operator: Exists
        effect: NoSchedule
      - operator: "Exists"
        effect: "NoExecute"
      - operator: "Exists"
        effect: "NoSchedule"

Kubernetes 插件配置应该类似于以下内容：

[FILTER]
        Name                kubernetes
        Match               application.*
        Kube_URL            https://kubernetes.default.svc:443
        Kube_Tag_Prefix     application.var.log.containers.
        Merge_Log           On
        Merge_Log_Key       log_processed
        K8S-Logging.Parser  On
        K8S-Logging.Exclude Off
        Labels              Off
        Annotations         Off
        Use_Kubelet         On
        Kubelet_Port        10250 
        Buffer_Size         0