实践-收集K8S日志

用 Filebeat 做 k8s 的日志采集，部署方式是采用DaemonSet的方式，采集时按照 k8s 集群的namespace进行分类。

K8S日志文件说明

        一般情况下，容器中的日志在输出到标准输出(stdout)时，会以*-json.log的命名方式保存在/var/lib/docker/containers目录中，当然如果修改了docker的数据目录，那就是在修改后的数据目录中了，例如：

        这里能看到，有这么个文件：/var/lib/docker/containers/container id/*-json.log，然后 k8s 默认会在/var/log/containers和/var/log/pods目录中会生成这些日志文件的软链接，如下所示：

然后，会看到这个目录下存在了此宿主机上的所有容器日志，文件的命名方式为：

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

上面这个是deployment的命名方式，其他的会有些不同，例如：DaemonSet，StatefulSet等，不过所有的都有一个共同点，就是

*_[nameSpace]_*.log

到这里，知道这个特性，就可以往下来看Filebeat的部署和配置了。

Filebeat部署

部署采用DaemonSet方式进行，参照官方文档部署即可：

配置文件：

vim filebeat-config.yml

---
apiVersion: v1
kind: ConfigMap
metadata:
  name: filebeat-config
  namespace: kube-system
  labels:
    k8s-app: filebeat
data:
  filebeat.yml: |-
    filebeat.inputs:
    - type: container
      enabled: true
      paths:
        - /var/log/containers/*-ingress*.log
      fields:
        event.dataset: k8s.ingress
      fields_under_root: true
      processors:
        - add_kubernetes_metadata:
            host: ${NODE_NAME}
            matchers:
              - logs_path:
                  logs_path: "/var/log/containers/"
    filebeat.autodiscover:
      providers:
        - type: kubernetes
          templates:
            - condition:
                equals:
                  kubernetes.namespace: default
              config:
                - type: container
                  paths:
                    - "/var/log/containers/*-${data.kubernetes.container.id}.log"
                  fields:
                    event.dataset: k8s.apps
                  fields_under_root: true
    filebeat.config.modules:
      path: ${path.config}/modules.d/*.yml
      reload.enabled: false
    setup.template.settings:
      index.number_of_shards: 1
    output.elasticsearch:
      hosts: ["192.168.220.31:9200","192.168.220.32:9200","192.168.220.33:9200"]
      indices:
        - index: "filebeat-%{[event.dataset]}-%{+yyyy.MM}"
    processors:
    - add_cloud_metadata:
    - add_host_metadata:
    - drop_fields:
        fields:
          - host
          - ecs
          - log
          - input
          - kubernetes

kubectl create -f filebeat-config.yml

RBAC权限：

vim filebeat-rbac.yml

---
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: RoleBinding
metadata:
  name: filebeat
  namespace: kube-system
subjects:
  - kind: ServiceAccount
    name: filebeat
    namespace: kube-system
roleRef:
  kind: Role
  name: filebeat
  apiGroup: rbac.authorization.k8s.io
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: filebeat-kubeadm-config
  namespace: kube-system
subjects:
  - kind: ServiceAccount
    name: filebeat
    namespace: kube-system
roleRef:
  kind: Role
  name: filebeat-kubeadm-config
  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: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: filebeat
  # should be the namespace where filebeat is running
  namespace: kube-system
  labels:
    k8s-app: filebeat
rules:
  - apiGroups:
      - coordination.k8s.io
    resources:
      - leases
    verbs: ["get", "create", "update"]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: filebeat-kubeadm-config
  namespace: kube-system
  labels:
    k8s-app: filebeat
rules:
  - apiGroups: [""]
    resources:
      - configmaps
    resourceNames:
      - kubeadm-config
    verbs: ["get"]
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: filebeat
  namespace: kube-system
  labels:
    k8s-app: filebeat

kubectl create -f filebeat-rbac.yml

Filebeat创建：

vim filebeat.yml

---
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:7.16.2
        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

kubectl create -f filebeat.yml

Tips：拉取镜像可能会超时，注意预先处理。

查看

部署完后即会按配置运行，查看ES中收集到的信息：

索引：

日志：