1.準備工作

思路: 在OpenShift容器平臺上以daemonset方式部署Fluentd收集各節點中的日誌。更改其配置讓日誌輸出到外部Elasticsearch中，最終通過Kibana展示。

資料：

     Fluentd官方配置文件：https://docs.fluentd.org/v0.12/articles/kubernetes-fluentd

     Fluentd-k8s專案地址：https://github.com/fluent/fluentd-kubernetes-daemonset（yaml模板檔案）

2.部署Fluentd

預設yaml檔案，建立之前先建立configmap。

---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: fluentd
  namespace: kube-system

---
apiVersion: rbac.authorization.k8s.io/v1beta1
kind: ClusterRole
metadata:
  name: fluentd
  namespace: kube-system
rules:
- apiGroups:
  - ""
  resources:
  - pods
  - namespaces
  verbs:
  - get
  - list
  - watch

---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
  name: fluentd
roleRef:
  kind: ClusterRole
  name: fluentd
  apiGroup: rbac.authorization.k8s.io
subjects:
- kind: ServiceAccount
  name: fluentd
  namespace: kube-system
---
apiVersion: extensions/v1beta1
kind: DaemonSet
metadata:
  name: fluentd
  namespace: kube-system
  labels:
    k8s-app: fluentd-logging
    version: v1
    kubernetes.io/cluster-service: "true"
spec:
  template:
    metadata:
      labels:
        k8s-app: fluentd-logging
        version: v1
        kubernetes.io/cluster-service: "true"
    spec:
      serviceAccount: fluentd
      serviceAccountName: fluentd
      tolerations:
      - key: node-role.kubernetes.io/master
        effect: NoSchedule
      containers:
      - name: fluentd
        image: docker.io/fluent/fluentd-kubernetes-daemonset:elasticsearch
 

        env:
          - name:  FLUENT_ELASTICSEARCH_HOST
            value: "192.168.0.129"
          - name:  FLUENT_ELASTICSEARCH_PORT
            value: "9200"
          - name: FLUENT_ELASTICSEARCH_SCHEME
            value: "http"
        resources:
          limits:
            memory: 200Mi
          requests:
            cpu: 100m
            memory: 200Mi
        volumeMounts:
        - name: varlog
          mountPath: /var/log
        - name: varlibdockercontainers
          mountPath: /var/lib/docker/containers
          readOnly: true
        - mountPath: /etc/fluent/
          name: config
          readOnly: true
      terminationGracePeriodSeconds: 30
      volumes:
      - name: varlog
        hostPath:
          path: /var/log
      - name: varlibdockercontainers
        hostPath:
          path: /var/lib/docker/containers
      - configMap:
          defaultMode: 420
          name: fluentd-logging
        name: config
 

#建立daemonset
oc create -f  fluentd-daemonset-elasticsearch.yaml

登入控制檯檢視，預設在kube-system空間中。