日誌收集之filebeat使用介紹

dogfei發表於2021-04-20

此係列文章一共分為三部分,分為filebeat部分,logstash部分,es部分。這裡會按照每天幾百億條的資料量來考慮,去設計、部署、優化這個日誌系統,來最大限度的利用資源,並達到一個最優的效能。本篇主要講解filebeat這一塊

介紹

版本:filebeat-7.12.0

是關於k8s的日誌採集,部署方式是採用DaemonSet的方式,採集時按照k8s叢集的namespace進行分類,然後根據namespace的名稱建立不同的topic到kafka中

image-20210419115501654

k8s日誌檔案說明

一般情況下,容器中的日誌在輸出到標準輸出(stdout)時,會以*-json.log的命名方式儲存在/var/lib/docker/containers目錄中,當然如果修改了docker的資料目錄,那就是在修改後的資料目錄中了,例如:

# tree /data/docker/containers
/data/docker/containers
├── 009227c00e48b051b6f5cb65128fd58412b845e0c6d2bec5904f977ef0ec604d
│   ├── 009227c00e48b051b6f5cb65128fd58412b845e0c6d2bec5904f977ef0ec604d-json.log
│   ├── checkpoints
│   ├── config.v2.json
│   ├── hostconfig.json
│   └── mounts

這裡能看到,有這麼個檔案: /data/docker/containers/container id/*-json.log,然後k8s預設會在/var/log/containers/var/log/pods目錄中會生成這些日誌檔案的軟連線,如下所示:

cattle-node-agent-tvhlq_cattle-system_agent-8accba2d42cbc907a412be9ea3a628a90624fb8ef0b9aa2bc6ff10eab21cf702.log
etcd-k8s-master01_kube-system_etcd-248e250c64d89ee6b03e4ca28ba364385a443cc220af2863014b923e7f982800.log

然後,會看到這個目錄下存在了此宿主機上的所有容器日誌,檔案的命名方式為:

[podName]_[nameSpace]_[depoymentName]-[containerId].log

上面這個是deployment的命名方式,其他的會有些不同,例如:DaemonSetStatefulSet等,不過所有的都有一個共同點,就是

*_[nameSpace]_*.log

到這裡,知道這個特性,就可以往下來看Filebeat的部署和配置了。

filebeat部署

部署採用的DaemonSet方式進行,這裡沒有啥可說的,參照官方文件直接部署即可

---
apiVersion: v1
data:
  filebeat.yml: |-
    filebeat.inputs:
    - type: container
      enabled: true
      paths:
      - /var/log/containers/*_bim5d-basic_*log
      fields:
        log_topic: bim5d-basic
        env: dev
    - type: container
      enabled: true
      paths:
      - /var/log/containers/*_bim5d-cost_*log
      fields:
        log_topic: bim5d-cost
        env: dev
    - type: container
      enabled: true
      paths:
      - /var/log/containers/*_giot-integration-test_*log
      fields:
        log_topic: giot-integration-test
        env: dev
    - type: container
      enabled: true
      paths:
      - /var/log/containers/*_infra-integration-test_*log
      fields:
        log_topic: infra-integration-test
        env: dev
    - type: container
      enabled: true
      paths:
      - /var/log/containers/*_gss-integration-test_*log
      fields:
        log_topic: gss-integration-test
        env: dev
    filebeat.config.modules:
      path: ${path.config}/modules.d/*.yml
      reload.enabled: false
    output.kafka:
      hosts: ["10.0.105.74:9092","10.0.105.76:9092","10.0.105.96:9092"]
      topic: '%{[fields.log_topic]}'
      partition.round_robin:
        reachable_only: true
kind: ConfigMap
metadata:
  name: filebeat-daemonset-config-test
  namespace: default
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
  name: filebeat
  namespace: kube-system
  labels:
    k8s-app: filebeat
spec:
  selector:
    matchLabels:
      k8s-app: filebeat
  template:
    metadata:
      labels:
        k8s-app: filebeat
    spec:
      serviceAccountName: filebeat
      terminationGracePeriodSeconds: 30
      hostNetwork: true
      dnsPolicy: ClusterFirstWithHostNet
      containers:
      - name: filebeat
        image: docker.elastic.co/beats/filebeat:7.12.0
        args: [
          "-c", "/etc/filebeat.yml",
          "-e",
        ]
        env:
        - name: NODE_NAME
          valueFrom:
            fieldRef:
              fieldPath: spec.nodeName
        securityContext:
          runAsUser: 0
          # If using Red Hat OpenShift uncomment this:
          #privileged: true
        resources:
          limits:
            memory: 200Mi
          requests:
            cpu: 100m
            memory: 100Mi
        volumeMounts:
        - name: config
          mountPath: /etc/filebeat.yml
          readOnly: true
          subPath: filebeat.yml
        - name: data
          mountPath: /usr/share/filebeat/data
        - name: varlibdockercontainers
          mountPath: /var/lib/docker/containers
          readOnly: true
        - name: varlog
          mountPath: /var/log
          readOnly: true
      volumes:
      - name: config
        configMap:
          defaultMode: 0640
          name: filebeat-config
      - name: varlibdockercontainers
        hostPath:
          path: /var/lib/docker/containers
      - name: varlog
        hostPath:
          path: /var/log
      # data folder stores a registry of read status for all files, so we don't send everything again on a Filebeat pod restart
      - name: data
        hostPath:
          # When filebeat runs as non-root user, this directory needs to be writable by group (g+w).
          path: /var/lib/filebeat-data
          type: DirectoryOrCreate
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: filebeat
subjects:
- kind: ServiceAccount
  name: filebeat
  namespace: kube-system
roleRef:
  kind: ClusterRole
  name: filebeat
  apiGroup: rbac.authorization.k8s.io
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: filebeat
  labels:
    k8s-app: filebeat
rules:
- apiGroups: [""] # "" indicates the core API group
  resources:
  - namespaces
  - pods
  - nodes
  verbs:
  - get
  - watch
  - list
- apiGroups: ["apps"]
  resources:
    - replicasets
  verbs: ["get", "list", "watch"]
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: filebeat
  namespace: kube-system
  labels:
    k8s-app: filebeat

啟動的話直接kubectl apply -f啟動即可,部署不是本篇的重點,這裡不做過多介紹。

官方部署參考:https://raw.githubusercontent.com/elastic/beats/7.12/deploy/kubernetes/filebeat-kubernetes.yaml

filebeat配置簡單介紹

這裡先簡單介紹下filebeat的配置結構

filebeat.inputs:

filebeat.config.modules:

processors:

output.xxxxx:

結構大概是這麼個結構,完整的資料流向簡單來說就是下面這個圖:

image-20210419225848048

前面也說了,我是根據根據名稱空間做分類,每一個名稱空間就是一個topic,如果要收集多個叢集,同樣也是使用名稱空間做分類,只不過topic的命名就需要加個k8s的叢集名,這樣方便去區分了,那既然是通過名稱空間來獲取日誌,那麼在配置inputs的時候就需要通過寫正則將指定名稱空間下的日誌檔案取出,然後讀取,例如:

filebeat.inputs:
- type: container
  enabled: true
  paths:
  - /var/log/containers/*_bim5d-basic_*log
  fields:
    log_topic: bim5d-basic
    env: dev

這裡我的名稱空間為bim5d-basic,然後通過正則*_bim5d-basic_*log來獲取帶有此名稱空間名的日誌檔案,隨後又加了個自定義欄位,方便下面建立topic時使用。
這裡是寫了一個名稱空間,如果有多個,就排開寫就行了,如下所示:

filebeat.inputs:
- type: container
  enabled: true
  paths:
  - /var/log/containers/*_bim5d-basic_*log
  fields:
    log_topic: bim5d-basic
    env: dev
- type: container
  enabled: true
  paths:
  - /var/log/containers/*_bim5d-cost_*log
  fields:
    log_topic: bim5d-cost
    env: dev
- type: container
  enabled: true
  paths:
  - /var/log/containers/*_giot-integration-test_*log
  fields:
    log_topic: giot-integration-test
    env: dev

這種寫法有一個不好的地方就是,如果名稱空間比較多,那麼整個配置就比較多,維護起來可能是個問題,所以建議將filebeat的配置檔案通過版本控制來管理起來

注意: 日誌的型別,要設定成container

上面說了通過名稱空間建立topic,我這裡加了一個自定義的欄位log_topic,就是後面的topic的名稱,但是這裡有很多的名稱空間,那在輸出的時候,如何動態去建立呢?

output.kafka:
  hosts: ["10.0.105.74:9092","10.0.105.76:9092","10.0.105.96:9092"]
  topic: '%{[fields.log_topic]}'
  partition.round_robin:
    reachable_only: true

注意這裡的寫法:%{[fields.log_topic]}

那麼完整的配置如下所示:

filebeat.inputs:
- type: container
  enabled: true
  paths:
  - /var/log/containers/*_bim5d-basic_*log
  fields:
    log_topic: bim5d-basic
    env: dev
- type: container
  enabled: true
  paths:
  - /var/log/containers/*_bim5d-cost_*log
  fields:
    log_topic: bim5d-cost
    env: dev
- type: container
  enabled: true
  paths:
  - /var/log/containers/*_giot-integration-test_*log
  fields:
    log_topic: giot-integration-test
    env: dev
output.kafka:
  hosts: ["10.0.105.74:9092","10.0.105.76:9092","10.0.105.96:9092"]
  topic: '%{[fields.log_topic]}'
  partition.round_robin:
    reachable_only: true

如果是不對日誌做任何處理,到這裡就結束了,但是這樣又視乎在檢視日誌的時候少了點什麼? 沒錯!到這裡你僅僅知道日誌內容,和該日誌來自於哪個名稱空間,但是你不知道該日誌屬於哪個服務,哪個pod,甚至說想檢視該服務的映象地址等,但是這些資訊在我們上面的配置方式中是沒有的,所以需要進一步的添磚加瓦。

這個時候就用到了一個配置項,叫做: processors, 看下官方的解釋

You can define processors in your configuration to process events before they are sent to the configured output

簡單來說就是處理日誌

下面來重點講一下這個地方,非常有用和重要

filebeat的processors使用介紹

新增K8s的基本資訊

在採集k8s的日誌時,如果按照上面那種配置方式,是沒有關於pod的一些資訊的,例如:

  • Pod Name
  • Pod UID
  • Namespace
  • Labels
  • 等等等等

那麼如果想新增這些資訊,就要使用processors中的一個工具,叫做: add_kubernetes_metadata, 字面意思就是新增k8s的一些後設資料資訊,使用方法可以先來看一段示例:

processors:
  - add_kubernetes_metadata:
      host: ${NODE_NAME}
      matchers:
      - logs_path:
          logs_path: "/var/log/containers/"

host: 指定要對filebeat起作用的節點,防止無法準確檢測到它,比如在主機網路模式下執行filebeat
matchers: 匹配器用於構造與索引建立的識別符號相匹配的查詢鍵
logs_path: 容器日誌的基本路徑,如果未指定,則使用Filebeat執行的平臺的預設日誌路徑

加上這個k8s的後設資料資訊之後,就可以在日誌裡面看到k8s的資訊了,看一下新增k8s資訊後的日誌格式:

{
  "@timestamp": "2021-04-19T07:07:36.065Z",
  "@metadata": {
    "beat": "filebeat",
    "type": "_doc",
    "version": "7.11.2"
  },
  "log": {
    "offset": 377708,
    "file": {
      "path": "/var/log/containers/geip-gateway-test-85545c868b-6nsvc_geip-function-test_geip-gateway-test-server-885412c0a8af6bfa7b3d7a341c3a9cb79a85986965e363e87529b31cb650aec4.log"
    }
  },
  "fields": {
    "env": "dev",
    "log_topic": "geip-function-test"
  },
  "host": {
    "name": "filebeat-fv484"
  },
  "agent": {
    "id": "7afbca43-3ec1-4cee-b5cb-1de1e955b717",
    "name": "filebeat-fv484",
    "type": "filebeat",
    "version": "7.11.2",
    "hostname": "filebeat-fv484",
    "ephemeral_id": "8fd29dee-da50-4c88-88d5-ebb6bbf20772"
  },
  "ecs": {
    "version": "1.6.0"
  },
  "stream": "stdout",
  "message": "2021-04-19 15:07:36.065  INFO 23 --- [trap-executor-0] c.n.d.s.r.aws.ConfigClusterResolver      : Resolving eureka endpoints via configuration",
  "input": {
    "type": "container"
  },
  "container": {
    "image": {
      "name": "packages.gxxxxxn.com/docxxxxxp/gexxxxxxxst:3.3.1-ent-release-SNAPSHOT.20210402191241_87c9b1f841c"
    },
    "id": "885412c0a8af6bfa7b3d7a341c3a9cb79a85986965e363e87529b31cb650aec4",
    "runtime": "docker"
  },
  "kubernetes": {
    "labels": {
      "pod-template-hash": "85545c868b",
      "app": "geip-gateway-test"
    },
    "container": {
      "name": "geip-gateway-test-server",
      "image": "packages.xxxxxxx.com/dxxxxxp/gxxxxxxxxt:3.3.1-ent-release-SNAPSHOT.20210402191241_87c9b1f841c"
    },
    "node": {
      "uid": "511d9dc1-a84e-4948-b6c8-26d3f1ba2e61",
      "labels": {
        "kubernetes_io/hostname": "k8s-node-09",
        "kubernetes_io/os": "linux",
        "beta_kubernetes_io/arch": "amd64",
        "beta_kubernetes_io/os": "linux",
        "cloudt-global": "true",
        "kubernetes_io/arch": "amd64"
      },
      "hostname": "k8s-node-09",
      "name": "k8s-node-09"
    },
    "namespace_uid": "4fbea846-44b8-4d4a-b03b-56e43cff2754",
    "namespace_labels": {
      "field_cattle_io/projectId": "p-lgxhz",
      "cattle_io/creator": "norman"
    },
    "pod": {
      "name": "gxxxxxxxxst-85545c868b-6nsvc",
      "uid": "1e678b63-fb3c-40b5-8aad-892596c5bd4d"
    },
    "namespace": "geip-function-test",
    "replicaset": {
      "name": "geip-gateway-test-85545c868b"
    }
  }
}

可以看到kubernetes這個key的value有關於pod的資訊,還有node的一些資訊,還有namespace資訊等,基本上關於k8s的一些關鍵資訊都包含了,非常的多和全。

但是,問題又來了,這一條日誌資訊有點太多了,有一半多不是我們想要的資訊,所以,我們需要去掉一些對於我們沒有用的欄位

刪除不必要的欄位

processors:
  - drop_fields:
      #刪除的多餘欄位
      fields:
        - host
        - ecs
        - log
        - agent
        - input
        - stream
        - container
      ignore_missing: true

元資訊:@metadata是不能刪除的

新增日誌時間

通過上面的日誌資訊,可以看到是沒有單獨的一個關於日誌時間的欄位的,雖然裡面有一個@timestamp,但不是北京時間,而我們要的是日誌的時間,message裡面倒是有時間,但是怎麼能把它取到並單獨新增一個欄位呢,這個時候就需要用到script了,需要寫一個js指令碼來替換。

processors:
  - script:
      lang: javascript
      id: format_time
      tag: enable
      source: >
        function process(event) {
            var str=event.Get("message");
            var time=str.split(" ").slice(0, 2).join(" ");
            event.Put("time", time);
        }
  - timestamp:
      field: time
      timezone: Asia/Shanghai
      layouts:
        - '2006-01-02 15:04:05'
        - '2006-01-02 15:04:05.999'
      test:
        - '2019-06-22 16:33:51'

新增完成後,會多一個time的欄位,在後面使用的時候,就可以使用這個欄位了。

重新拼接k8s源資訊

實際上,到這個程度就已經完成了我們的所有需求了,但是新增完k8s的資訊之後,多了很多無用的欄位,而我們如果想去掉那些沒用的欄位用drop_fields也可以,例如下面這種寫法:

processors:
  - drop_fields:
      #刪除的多餘欄位
      fields:
        - kubernetes.pod.uid
        - kubernetes.namespace_uid
        - kubernetes.namespace_labels
        - kubernetes.node.uid
        - kubernetes.node.labels
        - kubernetes.replicaset
        - kubernetes.labels
        - kubernetes.node.name
      ignore_missing: true

這樣寫也可以把無用的欄位去掉,但是結構層級沒有變化,巢狀了很多層,最終結果可能變成這個樣子

{
  "@timestamp": "2021-04-19T07:07:36.065Z",
  "@metadata": {
    "beat": "filebeat",
    "type": "_doc",
    "version": "7.11.2"
  },
  "fields": {
    "env": "dev",
    "log_topic": "geip-function-test"
  },
  "message": "2021-04-19 15:07:36.065  INFO 23 --- [trap-executor-0] c.n.d.s.r.aws.ConfigClusterResolver      : Resolving eureka endpoints via configuration",
  "kubernetes": {
    "container": {
      "name": "geip-gateway-test-server",
      "image": "packages.xxxxxxx.com/dxxxxxp/gxxxxxxxxt:3.3.1-ent-release-SNAPSHOT.20210402191241_87c9b1f841c"
    },
    "node": {
      "hostname": "k8s-node-09"
    },
    "pod": {
      "name": "gxxxxxxxxst-85545c868b-6nsvc"
    },
    "namespace": "geip-function-test"
  }
}

這樣在後面使用es建立template的時候,就會巢狀好多層,查詢起來也很不方便,既然這樣那我們就優化下這個層級結構,繼續script這個外掛

processors:
  - script:
      lang: javascript
      id: format_k8s
      tag: enable
      source: >
        function process(event) {
            var k8s=event.Get("kubernetes");
            var newK8s = {
                podName: k8s.pod.name,
                nameSpace: k8s.namespace,
                imageAddr: k8s.container.name,
                hostName: k8s.node.hostname
            }
            event.Put("k8s", newK8s);
        }

這裡單獨建立了一個欄位k8s,欄位裡包含:podName, nameSpace, imageAddr, hostName等關鍵資訊,最後再把kubernetes這個欄位drop掉就可以了。最終結果如下:

{
  "@timestamp": "2021-04-19T07:07:36.065Z",
  "@metadata": {
    "beat": "filebeat",
    "type": "_doc",
    "version": "7.11.2"
  },
  "fields": {
    "env": "dev",
    "log_topic": "geip-function-test"
  },
  "time": "2021-04-19 15:07:36.065",
  "message": "2021-04-19 15:07:36.065  INFO 23 --- [trap-executor-0] c.n.d.s.r.aws.ConfigClusterResolver      : Resolving eureka endpoints via configuration",
  "k8s": {
      "podName": "gxxxxxxxxst-85545c868b-6nsvc",
      "nameSpace": "geip-function-test",
      "imageAddr": "packages.xxxxxxx.com/dxxxxxp/gxxxxxxxxt:3.3.1-ent-release-SNAPSHOT.20210402191241_87c9b1f841c",
      "hostName": "k8s-node-09"
  }
}

這樣看起來就非常清爽了。

下面貼一些一個完整的示例:
configmap參考

apiVersion: v1
data:
  filebeat.yml: |-
    filebeat.inputs:
    - type: container
      enabled: true
      paths:
      - /var/log/containers/*_bim5d-basic_*log
      fields:
        namespace: bim5d-basic
        k8s: cluster01
        env: prod
      multiline.pattern: '^[0-9]{4}-[0-9]{2}-[0-9]{2} [0-9]{2}|^[1-9]\d*\.[1-9]\d*\.[1-9]\d*\.[1-9]\d*'
      multiline.negate: true
      multiline.match: after
      multiline.timeout: 10s
    - type: container
      enabled: true
      paths:
      - /var/log/containers/*_bim5d-cost_*log
      fields:
        namespace: bim5d-cost
        k8s: cluster01
        env: prod
      multiline.pattern: '^[0-9]{4}-[0-9]{2}-[0-9]{2} [0-9]{2}|^[1-9]\d*\.[1-9]\d*\.[1-9]\d*\.[1-9]\d*'
      multiline.negate: true
      multiline.match: after
      multiline.timeout: 10s
    filebeat.config.modules:
      path: ${path.config}/modules.d/*.yml
      reload.enabled: false
    processors:
      - add_kubernetes_metadata:
          #新增k8s描述欄位
          default_indexers.enabled: true
          default_matchers.enabled: true
          host: ${NODE_NAME}
          matchers:
          - logs_path:
              logs_path: "/var/log/containers/"
      - drop_event.when.regexp:
          or:
            kubernetes.pod.name: "filebeat.*"
            kubernetes.pod.name: "external-dns.*"
            kubernetes.pod.name: "coredns.*"
      - drop_fields:
          #刪除的多餘欄位
          fields:
            - host
            - tags
            - ecs
            - log
            - prospector
            - agent
            - input
            - beat
            - offset
            - stream
            - container
            - kubernetes
          ignore_missing: true
      - timestamp:
          field: start_time
          timezone: Asia/Shanghai
          layouts:
            - '2006-01-02 15:04:05'
            - '2006-01-02 15:04:05.999'
          test:
            - '2019-06-22 16:33:51'      
    output.kafka:
      hosts: ["10.0.105.74:9092","10.0.105.76:9092","10.0.105.96:9092"]
      topic: '%{[fields.k8s]}-%{[fields.namespace]}'
      partition.round_robin:
        reachable_only: true
kind: ConfigMap
metadata:
  name: filebeat-daemonset-config
  namespace: default

總結

個人認為讓filebeat在收集日誌的第一層做一些處理,能縮短整個過程的處理時間,因為瓶頸大多在es和logstash,所以一些耗時的操作儘量在filebeat這塊去處理,如果處理不了在使用logstash,另外一個非常容易忽視的一點就是,對於日誌內容的簡化,這樣能顯著降低日誌的體積,我做過測試,同樣的日誌條數,未做簡化的體積達到20G,而優化後的體積不到10G,這樣的話對於整個es叢集來說可以說是非常的友好和作用巨大了。

另外,可以通過版本控制,來管理filebeat的配置檔案,這樣在維護時也能有個記錄,變化管理。


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