[AWS] Fluentd를 사용하여 EKS Log를 CloudWatch로 전송하는 방법

AWS EKS Document : https://docs.aws.amazon.com/ko_kr/AmazonCloudWatch/latest/monitoring/Container-Insights-setup-logs.html

 

 

[ 사전 준비 ]

- EKS Cluster에 접속 할 환경에 eksctl, kubectl, git 설치

- EKS Node Role에 Cloudwatch Logs 전체 권한 할당

※중요※ Nodegroup에 한함, daemonSet의 경우 fargate는 적용 방법이 다름

 

 

 

[ CLI 작업 ]

1. NameSpace 생성

$ kubectl apply -f https://raw.githubusercontent.com/aws-samples/amazon-cloudwatch-container-insights/master/k8s-yaml-templates/cloudwatch-namespace.yaml

2. iamserviceaccount 생성

$ eksctl create iamserviceaccount --name cwagent-prometheus --namespace amazon-cloudwatch --cluster <cluster-name> --attach-policy-arn arn:aws:iam::aws:policy/CloudWatchAgentServerPolicy --approve --override-existing-serviceaccounts

3. configmap 생성

$ kubectl create configmap cluster-info --from-literal=cluster.name=<cluster name> --from-literal=logs.region=<region-code> -n amazon-cloudwatch

4. fluentd 배포

$ kubectl apply -f https://raw.githubusercontent.com/aws-samples/amazon-cloudwatch-container-insights/master/k8s-yaml-templates/fluentd/fluentd.yaml

5. AWS Console > Cloudwatch > Log groups에서 생성된 Log groups 확인

• /aws/containerinsights/<cluster name>/application
• /aws/containerinsights/<cluster name>/dataplane
• /aws/containerinsights/<cluster name>/host
• /aws/containerinsights/<cluster name>/performance

 

[ 추가 작업 ]

- 기본적으로 제공되는 fluentd.yaml 파일을 사용하여 배포하면 원하는대로 로그가 보이지 않을 수 있으므로 저장하고 수정하여 배포 하는것을 추천

$ wget https://raw.githubusercontent.com/aws-samples/amazon-cloudwatch-container-insights/master/k8s-yaml-templates/fluentd/fluentd.yaml

$ vi fluentd.yaml

apiVersion: v1
kind: ServiceAccount
metadata:
  name: fluentd
  namespace: amazon-cloudwatch
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: fluentd-role
rules:
  - apiGroups: [""]
    resources:
      - namespaces
      - pods
      - pods/logs
    verbs: ["get", "list", "watch"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: fluentd-role-binding
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: fluentd-role
subjects:
  - kind: ServiceAccount
    name: fluentd
    namespace: amazon-cloudwatch
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: fluentd-config
  namespace: amazon-cloudwatch
  labels:
    k8s-app: fluentd-cloudwatch
data:
  fluent.conf: |
    @include containers.conf
    @include systemd.conf
    @include host.conf

    <match fluent.**>
      @type null
    </match>
  containers.conf: |
    <source>
      @type tail
      @id in_tail_container_logs
      @label @containers
      path /var/log/containers/*.log
      exclude_path ["/var/log/containers/cloudwatch-agent*", "/var/log/containers/fluentd*"]
      pos_file /var/log/fluentd-containers.log.pos
      tag *
      read_from_head true
      <parse>
        @type json
        time_format %Y-%m-%dT%H:%M:%S.%NZ
      </parse>
    </source>

    <source>
      @type tail
      @id in_tail_cwagent_logs
      @label @cwagentlogs
      path /var/log/containers/cloudwatch-agent*
      pos_file /var/log/cloudwatch-agent.log.pos
      tag *
      read_from_head true
      <parse>
        @type json
        time_format %Y-%m-%dT%H:%M:%S.%NZ
      </parse>
    </source>

    <source>
      @type tail
      @id in_tail_fluentd_logs
      @label @fluentdlogs
      path /var/log/containers/fluentd*
      pos_file /var/log/fluentd.log.pos
      tag *
      read_from_head true
      <parse>
        @type json
        time_format %Y-%m-%dT%H:%M:%S.%NZ
      </parse>
    </source>

    <label @fluentdlogs>
      <filter **>
        @type kubernetes_metadata
        @id filter_kube_metadata_fluentd
      </filter>

      <filter **>
        @type record_transformer
        @id filter_fluentd_stream_transformer
        <record>
          stream_name ${tag_parts[3]}
        </record>
      </filter>

      <match **>
        @type relabel
        @label @NORMAL
      </match>
    </label>

    <label @containers>
      <filter **>
        @type kubernetes_metadata
        @id filter_kube_metadata
      </filter>

      <filter **>
        @type record_transformer
        @id filter_containers_stream_transformer
        <record>
          stream_name ${tag_parts[3]}
        </record>
      </filter>

      <filter **>
        @type concat
        key log
        multiline_start_regexp /^\S/
        separator ""
        flush_interval 5
        timeout_label @NORMAL
      </filter>

      <match **>
        @type relabel
        @label @NORMAL
      </match>
    </label>

    <label @cwagentlogs>
      <filter **>
        @type kubernetes_metadata
        @id filter_kube_metadata_cwagent
      </filter>

      <filter **>
        @type record_transformer
        @id filter_cwagent_stream_transformer
        <record>
          stream_name ${tag_parts[3]}
        </record>
      </filter>

      <filter **>
        @type concat
        key log
        multiline_start_regexp /^\d{4}[-/]\d{1,2}[-/]\d{1,2}/
        separator ""
        flush_interval 5
        timeout_label @NORMAL
      </filter>

      <match **>
        @type relabel
        @label @NORMAL
      </match>
    </label>

    <label @NORMAL>
      <match **>
        @type cloudwatch_logs
        @id out_cloudwatch_logs_containers
        region "#{ENV.fetch('REGION')}"
        log_group_name "/aws/containerinsights/#{ENV.fetch('CLUSTER_NAME')}/application"
        log_stream_name_key stream_name
        remove_log_stream_name_key true
        auto_create_stream true
        <buffer>
          flush_interval 5
          chunk_limit_size 2m
          queued_chunks_limit_size 32
          retry_forever true
        </buffer>
      </match>
    </label>
  systemd.conf: |
    <source>
      @type systemd
      @id in_systemd_kubelet
      @label @systemd
      filters [{ "_SYSTEMD_UNIT": "kubelet.service" }]
      <entry>
        field_map {"MESSAGE": "message", "_HOSTNAME": "hostname", "_SYSTEMD_UNIT": "systemd_unit"}
        field_map_strict true
      </entry>
      path /var/log/journal
      <storage>
        @type local
        persistent true
        path /var/log/fluentd-journald-kubelet-pos.json
      </storage>
      read_from_head true
      tag kubelet.service
    </source>

    <source>
      @type systemd
      @id in_systemd_kubeproxy
      @label @systemd
      filters [{ "_SYSTEMD_UNIT": "kubeproxy.service" }]
      <entry>
        field_map {"MESSAGE": "message", "_HOSTNAME": "hostname", "_SYSTEMD_UNIT": "systemd_unit"}
        field_map_strict true
      </entry>
      path /var/log/journal
      <storage>
        @type local
        persistent true
        path /var/log/fluentd-journald-kubeproxy-pos.json
      </storage>
      read_from_head true
      tag kubeproxy.service
    </source>

    <source>
      @type systemd
      @id in_systemd_docker
      @label @systemd
      filters [{ "_SYSTEMD_UNIT": "docker.service" }]
      <entry>
        field_map {"MESSAGE": "message", "_HOSTNAME": "hostname", "_SYSTEMD_UNIT": "systemd_unit"}
        field_map_strict true
      </entry>
      path /var/log/journal
      <storage>
        @type local
        persistent true
        path /var/log/fluentd-journald-docker-pos.json
      </storage>
      read_from_head true
      tag docker.service
    </source>

    <label @systemd>
      <filter **>
        @type kubernetes_metadata
        @id filter_kube_metadata_systemd
      </filter>

      <filter **>
        @type record_transformer
        @id filter_systemd_stream_transformer
        <record>
          stream_name ${tag}-${record["hostname"]}
        </record>
      </filter>

      <match **>
        @type cloudwatch_logs
        @id out_cloudwatch_logs_systemd
        region "#{ENV.fetch('REGION')}"
        log_group_name "/aws/containerinsights/#{ENV.fetch('CLUSTER_NAME')}/dataplane"
        log_stream_name_key stream_name
        auto_create_stream true
        remove_log_stream_name_key true
        <buffer>
          flush_interval 5
          chunk_limit_size 2m
          queued_chunks_limit_size 32
          retry_forever true
        </buffer>
      </match>
    </label>
  host.conf: |
    <source>
      @type tail
      @id in_tail_dmesg
      @label @hostlogs
      path /var/log/dmesg
      pos_file /var/log/dmesg.log.pos
      tag host.dmesg
      read_from_head true
      <parse>
        @type syslog
      </parse>
    </source>

    <source>
      @type tail
      @id in_tail_secure
      @label @hostlogs
      path /var/log/secure
      pos_file /var/log/secure.log.pos
      tag host.secure
      read_from_head true
      <parse>
        @type syslog
      </parse>
    </source>

    <source>
      @type tail
      @id in_tail_messages
      @label @hostlogs
      path /var/log/messages
      pos_file /var/log/messages.log.pos
      tag host.messages
      read_from_head true
      <parse>
        @type syslog
      </parse>
    </source>

    <label @hostlogs>
      <filter **>
        @type kubernetes_metadata
        @id filter_kube_metadata_host
      </filter>

      <filter **>
        @type record_transformer
        @id filter_containers_stream_transformer_host
        <record>
          stream_name ${tag}-${record["host"]}
        </record>
      </filter>

      <match host.**>
        @type cloudwatch_logs
        @id out_cloudwatch_logs_host_logs
        region "#{ENV.fetch('REGION')}"
        log_group_name "/aws/containerinsights/#{ENV.fetch('CLUSTER_NAME')}/host"
        log_stream_name_key stream_name
        remove_log_stream_name_key true
        auto_create_stream true
        <buffer>
          flush_interval 5
          chunk_limit_size 2m
          queued_chunks_limit_size 32
          retry_forever true
        </buffer>
      </match>
    </label>
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: fluentd-cloudwatch
  namespace: amazon-cloudwatch
spec:
  selector:
    matchLabels:
      k8s-app: fluentd-cloudwatch
  template:
    metadata:
      labels:
        k8s-app: fluentd-cloudwatch
      annotations:
        configHash: 8915de4cf9c3551a8dc74c0137a3e83569d28c71044b0359c2578d2e0461825
    spec:
      serviceAccountName: fluentd
      terminationGracePeriodSeconds: 30
      # Because the image's entrypoint requires to write on /fluentd/etc but we mount configmap there which is read-only,
      # this initContainers workaround or other is needed.
      # See https://github.com/fluent/fluentd-kubernetes-daemonset/issues/90
      initContainers:
        - name: copy-fluentd-config
          image: busybox
          command: ['sh', '-c', 'cp /config-volume/..data/* /fluentd/etc']
          volumeMounts:
            - name: config-volume
              mountPath: /config-volume
            - name: fluentdconf
              mountPath: /fluentd/etc
        - name: update-log-driver
          image: busybox
          command: ['sh','-c','']
      containers:
        - name: fluentd-cloudwatch
          image: fluent/fluentd-kubernetes-daemonset:v1.7.3-debian-cloudwatch-1.0
          env:
            - name: REGION
              valueFrom:
                configMapKeyRef:
                  name: cluster-info
                  key: logs.region
            - name: CLUSTER_NAME
              valueFrom:
                configMapKeyRef:
                  name: cluster-info
                  key: cluster.name
            - name: CI_VERSION
              value: "k8s/1.0.1"
          resources:
            limits:
              memory: 400Mi
            requests:
              cpu: 100m
              memory: 200Mi
          volumeMounts:
            - name: config-volume
              mountPath: /config-volume
            - name: fluentdconf
              mountPath: /fluentd/etc
            - name: varlog
              mountPath: /var/log
            - name: varlibdockercontainers
              mountPath: /var/lib/docker/containers
              readOnly: true
            - name: runlogjournal
              mountPath: /run/log/journal
              readOnly: true
            - name: dmesg
              mountPath: /var/log/dmesg
              readOnly: true
      volumes:
        - name: config-volume
          configMap:
            name: fluentd-config
        - name: fluentdconf
          emptyDir: {}
        - name: varlog
          hostPath:
            path: /var/log
        - name: varlibdockercontainers
          hostPath:
            path: /var/lib/docker/containers
        - name: runlogjournal
          hostPath:
            path: /run/log/journal
        - name: dmesg
          hostPath:
            path: /var/log/dmesg