使用ELK收集k8s集群日志

使用ELK收集k8s平台日志

1.收集哪些日志？

• K8S系统的组件日志
• K8S Cluster里面部署的应用程序日志

 - 标准输出

 - 日志文件 （输出到指定文件里）

 - 日志轮转（本地保留30天）

  - 日志格式  （json，kv）

如果是kubeadm方式部署的k8s 日志是收集的 /var/log/message

如果是二进制部署的k8s 日志是配置文件中定义的日志路径

应用容器日志

/var/lib/docker/contianers/*/*-json.log

docker配置文件中定义了 默认日志格式为json

pod的日志路径

/var/lib/kubelet/pods/*/volumes/

2.ELK收集日志架构

其中logstash 是非必选的组件，如果日志场景比较复杂的时候可以加上logstash做出更好的预处理然后存入ES。

3.容器中的日志怎么收集

方案一：

Node上部署一个日志收集程序

• DaemonSet方式部署日志收集程序
• 对本节点/var/log/kubelet/pods和 /var/lib/docker/containers/两个目录下的日志进 行采集
• Pod中容器日志目录挂载到宿主机统一目录上

方案二：

Pod中附加专用日志收集的容器

• 每个运行应用程序的Pod中增加一个日志 收集容器，使用emtyDir共享日志目录让 日志收集程序读取到。

方案三：

应用程序直接推送日志

• 超出Kubernetes范围

方案比较：

方式	优点	缺点
方案一：Node上部署一个日志收集程序	每个Node仅需部署一个日志收集程序， 资源消耗少，对应用无侵入	应用程序日志如果写到标准输出和标准错误输出， 那就不支持多行日志。
方案二：Pod中附加专用日志收集的容器	低耦合	每个Pod启动一个日志收集代理，增加资源消耗， 并增加运维维护成本
方案三：应用程序直接推送日志	无需额外收集工具	浸入应用，增加应用复杂度

4.k8s部署efk

mkdir efk  &&  cd efk

elasticsearch.yaml

apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: elasticsearch
  namespace: kube-system
  labels:
    k8s-app: elasticsearch
spec:
  serviceName: elasticsearch
  selector:
    matchLabels:
      k8s-app: elasticsearch
  template:
    metadata:
      labels:
        k8s-app: elasticsearch
    spec:
      containers:
      - image: elasticsearch:7.3.2
        name: elasticsearch
        resources:
          limits:
            cpu: 1
            memory: 2Gi
          requests:
            cpu: 0.5 
            memory: 500Mi
        env:
          - name: "discovery.type"
            value: "single-node"
          - name: ES_JAVA_OPTS
            value: "-Xms512m -Xmx2g" 
        ports:
        - containerPort: 9200
          name: db
          protocol: TCP
        volumeMounts:
        - name: elasticsearch-data
          mountPath: /usr/share/elasticsearch/data
  volumeClaimTemplates:
  - metadata:
      name: elasticsearch-data
    spec:
      storageClassName: "managed-nfs-storage"
      accessModes: [ "ReadWriteOnce" ]
      resources:
        requests:
          storage: 20Gi

---

apiVersion: v1
kind: Service
metadata:
  name: elasticsearch
  namespace: kube-system
spec:
  clusterIP: None
  ports:
  - port: 9200
    protocol: TCP
    targetPort: db
  selector:
    k8s-app: elasticsearch

kibana.yml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: kibana
  namespace: kube-system
  labels:
    k8s-app: kibana
spec:
  replicas: 1
  selector:
    matchLabels:
      k8s-app: kibana
  template:
    metadata:
      labels:
        k8s-app: kibana
    spec:
      containers:
      - name: kibana
        image: kibana:7.3.2
        resources:
          limits:
            cpu: 1
            memory: 500Mi
          requests:
            cpu: 0.5 
            memory: 200Mi
        env:
          - name: ELASTICSEARCH_HOSTS
            value: http://elasticsearch:9200
        ports:
        - containerPort: 5601
          name: ui
          protocol: TCP

---
apiVersion: v1
kind: Service
metadata:
  name: kibana
  namespace: kube-system
spec:
  type: NodePort
  ports:
  - port: 5601
    protocol: TCP
    targetPort: ui
    nodePort: 30601
  selector:
    k8s-app: kibana

---
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: kibana
  namespace: kube-system
spec:
  rules:
  - host: kibana.ctnrs.com
    http:
      paths:
      - path: /
        backend:
          serviceName: kibana
          servicePort: 5601 

使用node ip：30601  访问kibana

kibana页面

由于kibana.yaml中定义了数据来源为http://elasticsearch:9200

kibana会自动获取存在elasticsearch中日志数据

filebeat-kubernetes.yaml

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: filebeat-config
  namespace: kube-system
  labels:
    k8s-app: filebeat
data:
  filebeat.yml: |-
    filebeat.config:
      inputs:
        # Mounted `filebeat-inputs` configmap:
        path: ${path.config}/inputs.d/*.yml
        # Reload inputs configs as they change:
        reload.enabled: false
      modules:
        path: ${path.config}/modules.d/*.yml
        # Reload module configs as they change:
        reload.enabled: false

    # To enable hints based autodiscover, remove `filebeat.config.inputs` configuration and uncomment this:
    #filebeat.autodiscover:
    #  providers:
    #    - type: kubernetes
    #      hints.enabled: true

    output.elasticsearch:
      hosts: ['${ELASTICSEARCH_HOST:elasticsearch}:${ELASTICSEARCH_PORT:9200}']
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: filebeat-inputs
  namespace: kube-system
  labels:
    k8s-app: filebeat
data:
  kubernetes.yml: |-
    - type: docker
      containers.ids:
      - "*"
      processors:
        - add_kubernetes_metadata:
            in_cluster: true
---
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
      containers:
      - name: filebeat
        image: elastic/filebeat:7.3.2
        args: [
          "-c", "/etc/filebeat.yml",
          "-e",
        ]
        env:
        - name: ELASTICSEARCH_HOST
          value: elasticsearch
        - name: ELASTICSEARCH_PORT
          value: "9200"
        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: inputs
          mountPath: /usr/share/filebeat/inputs.d
          readOnly: true
        - name: data
          mountPath: /usr/share/filebeat/data
        - name: varlibdockercontainers
          mountPath: /var/lib/docker/containers
          readOnly: true
      volumes:
      - name: config
        configMap:
          defaultMode: 0600
          name: filebeat-config
      - name: varlibdockercontainers
        hostPath:
          path: /var/lib/docker/containers
      - name: inputs
        configMap:
          defaultMode: 0600
          name: filebeat-inputs
# 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:
          path: /var/lib/filebeat-data
          type: DirectoryOrCreate
---
apiVersion: rbac.authorization.k8s.io/v1beta1
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/v1beta1
kind: ClusterRole
metadata:
  name: filebeat
  labels:
    k8s-app: filebeat
rules:
- apiGroups: [""] # "" indicates the core API group
  resources:
  - namespaces
  - pods
  verbs:
  - get
  - watch
  - list
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: filebeat
  namespace: kube-system
  labels:
    k8s-app: filebeat
---

当filebeat起来之后 kibana会收到来自 filebeat处理后存在elasticsearch中的日志

创建索引匹配

数据展示

可以调节左侧边栏的avaliable fields  自定义展示对应字段。

5.方案二：Pod中附加专用日志收集的容器

k8s-logs.yaml

apiVersion: v1
kind: ConfigMap
metadata:
  name: k8s-logs-filebeat-config
  namespace: kube-system 
  
data:
  filebeat.yml: |
    filebeat.inputs:
      - type: log
        paths:
          - /var/log/messages  
        fields:
          app: k8s 
          type: module 
        fields_under_root: true

    setup.ilm.enabled: false
    setup.template.name: "k8s-module"
    setup.template.pattern: "k8s-module-*"

    output.elasticsearch:
      hosts: ['elasticsearch.kube-system:9200']
      index: "k8s-module-%{+yyyy.MM.dd}"

---

apiVersion: apps/v1
kind: DaemonSet 
metadata:
  name: k8s-logs
  namespace: kube-system
spec:
  selector:
    matchLabels:
      project: k8s 
      app: filebeat
  template:
    metadata:
      labels:
        project: k8s
        app: filebeat
    spec:
      containers:
      - name: filebeat
        image: elastic/filebeat:7.3.2
        args: [
          "-c", "/etc/filebeat.yml",
          "-e",
        ]
        resources:
          requests:
            cpu: 100m
            memory: 100Mi
          limits:
            cpu: 500m
            memory: 500Mi
        securityContext:
          runAsUser: 0
        volumeMounts:
        - name: filebeat-config
          mountPath: /etc/filebeat.yml
          subPath: filebeat.yml
        - name: k8s-logs 
          mountPath: /var/log/messages
      volumes:
      - name: k8s-logs
        hostPath: 
          path: /var/log/messages
      - name: filebeat-config
        configMap:
          name: k8s-logs-filebeat-config

查看索引管理

使用过滤器

对于java异常的日志，需要多行匹配

一个java应用的 日志收集demo

apiVersion: apps/v1
kind: Deployment
metadata:
  name: java-demo
  namespace: test
spec:
  replicas: 2
  selector:
    matchLabels:
      project: www
      app: java-demo
  template:
    metadata:
      labels:
        project: www
        app: java-demo
    spec:
      imagePullSecrets: 
      - name: "docker-regsitry-auth"
      containers:
      - image: 192.168.31.70/demo/java-demo:v2
        name: java
        imagePullPolicy: Always
        ports:
        - containerPort: 8080
          name: web
          protocol: TCP
        resources:
          requests:
            cpu: 0.5
            memory: 1Gi
          limits:
            cpu: 1
            memory: 2Gi
        livenessProbe:
          httpGet:
            path: /
            port: 8080
          initialDelaySeconds: 60
          timeoutSeconds: 20
        readinessProbe:
          httpGet:
            path: /
            port: 8080
          initialDelaySeconds: 60
          timeoutSeconds: 20
        volumeMounts:
        - name: tomcat-logs 
          mountPath: /usr/local/tomcat/logs

      - name: filebeat
        image: elastic/filebeat:7.3.2 
        args: [
          "-c", "/etc/filebeat.yml",
          "-e",
        ]
        resources:
          limits:
            memory: 500Mi
          requests:
            cpu: 100m
            memory: 100Mi
        securityContext:
          runAsUser: 0
        volumeMounts:
        - name: filebeat-config
          mountPath: /etc/filebeat.yml
          subPath: filebeat.yml
        - name: tomcat-logs 
          mountPath: /usr/local/tomcat/logs
      volumes:
      - name: tomcat-logs
        emptyDir: {}
      - name: filebeat-config
        configMap:
          name: filebeat-config
---
apiVersion: v1
kind: ConfigMap
metadata:
  name: filebeat-config
  namespace: test
  
data:
  filebeat.yml: |-
    filebeat.inputs:
    - type: log
      paths:
        - /usr/local/tomcat/logs/catalina.*
      # tags: ["tomcat"]
      fields:
        app: www
        type: tomcat-catalina
      fields_under_root: true
      multiline:
        pattern: '^['
        negate: true
        match: after
    setup.ilm.enabled: false
    setup.template.name: "tomcat-catalina"
    setup.template.pattern: "tomcat-catalina-*"
    output.elasticsearch:
      hosts: ['elasticsearch.kube-system:9200']
      index: "tomcat-catalina-%{+yyyy.MM.dd}"

针对java异常设置的多行匹配规则。

待日志写入到 es时，配置索引匹配