使用 Loki 实现 Kubernetes 容器日志监控

Posted 2022-05-19 愿许浪尽天涯

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使用 Loki 实现 Kubernetes 容器日志监控

一、基本介绍
- 1.Loki 架构
- 2.Loki 工作原理
二、使用 Loki 实现容器日志监控

一、基本介绍

Loki 是由 Grafana Labs 团队开发的，基于 Go 语言实现，是一个水平可扩展，高可用性，多租户的日志聚合系统。它的设计非常经济高效且易于操作，因为它不会为日志内容编制索引，而是为每个日志流配置一组标签。Loki 项目受 Prometheus 启发。

官方的介绍就是：Like Prometheus, but for logs，类似于 Prometheus 的日志系统。

1.Loki 架构

Loki：主服务，用于存储日志和处理查询。
Promtail：代理服务，用于采集日志，并转发给 Loki。
Grafana：通过 Web 界面来提供数据展示、查询、告警等功能。

2.Loki 工作原理

首先由 Promtail 进行日志采集，并发送给 Distributor 组件，Distributor 组件会对接收到的日志流进行正确性校验，并将验证后的日志分批并行发送给 Ingester 组件。Ingester 组件会将接收过来的日志流构建成数据块，并进行压缩后存放到所连接的后端存储中。

Querier 组件，用于接收 HTTP 查询请求，并将查询请求转发给 Ingester 组件，来返回存在 Ingester 内存中的数据。要是在 Ingester 的内存中没有找到符合条件的数据时，那么 Querier 组件便会直接在后端存储中进行查询（内置去重功能）。

二、使用 Loki 实现容器日志监控

1.安装 Loki

1）创建 RBAC 授权

[root@k8s-master01 ~]# cat <<END > loki-rbac.yaml
apiVersion: v1
kind: Namespace
metadata:
  name: logging
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: loki
  namespace: logging
---
apiVersion: rbac.authorization.k8s.io/v1
kind: Role
metadata:
  name: loki
  namespace: logging
rules:
- apiGroups: ["extensions"]
  resources: ["podsecuritypolicies"]
  verbs: ["use"]
  resourceNames: [loki]
---
apiVersion: rbac.authorization.k8s.io/v1
kind: RoleBinding
metadata:
  name: loki
  namespace: logging
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: Role
  name: loki
subjects:
- kind: ServiceAccount
  name: loki
END
[root@k8s-master01 ~]# kubectl create -f loki-rbac.yaml

2）创建 ConfigMap 文件

[root@k8s-master01 ~]# cat <<END > loki-configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: loki
  namespace: logging
  labels:
    app: loki
data:
  loki.yaml: |
    auth_enabled: false
    ingester:
      chunk_idle_period: 3m
      chunk_block_size: 262144
      chunk_retain_period: 1m
      max_transfer_retries: 0
      lifecycler:
        ring:
          kvstore:
            store: inmemory
          replication_factor: 1
    limits_config:
      enforce_metric_name: false
      reject_old_samples: true
      reject_old_samples_max_age: 168h
    schema_config:
      configs:
      - from: "2022-05-15"
        store: boltdb-shipper
        object_store: filesystem
        schema: v11
        index:
          prefix: index_
          period: 24h
    server:
      http_listen_port: 3100
    storage_config:
      boltdb_shipper:
        active_index_directory: /data/loki/boltdb-shipper-active
        cache_location: /data/loki/boltdb-shipper-cache
        cache_ttl: 24h         
        shared_store: filesystem
      filesystem:
        directory: /data/loki/chunks
    chunk_store_config:
      max_look_back_period: 0s
    table_manager:
      retention_deletes_enabled: true
      retention_period: 48h
    compactor:
      working_directory: /data/loki/boltdb-shipper-compactor
      shared_store: filesystem
END
[root@k8s-master01 ~]# kubectl create -f loki-configmap.yaml

3）创建 StatefulSet

[root@k8s-master01 ~]# cat <<END > loki-statefulset.yaml 
apiVersion: v1
kind: Service
metadata:
  name: loki
  namespace: logging
  labels:
    app: loki
spec:
  type: NodePort
  ports:
    - port: 3100
      protocol: TCP
      name: http-metrics
      targetPort: http-metrics
      nodePort: 30100
  selector:
    app: loki
---
apiVersion: apps/v1
kind: StatefulSet
metadata:
  name: loki
  namespace: logging
  labels:
    app: loki
spec:
  podManagementPolicy: OrderedReady
  replicas: 1
  selector:
    matchLabels:
      app: loki
  serviceName: loki
  updateStrategy:
    type: RollingUpdate
  template:
    metadata:
      labels:
        app: loki
    spec:
      serviceAccountName: loki
      initContainers:
      - name: chmod-data
        image: busybox:1.28.4
        imagePullPolicy: IfNotPresent
        command: ["chmod","-R","777","/loki/data"]
        volumeMounts:
        - name: storage
          mountPath: /loki/data
      containers:
        - name: loki
          image: grafana/loki:2.3.0
          imagePullPolicy: IfNotPresent
          args:
            - -config.file=/etc/loki/loki.yaml
          volumeMounts:
            - name: config
              mountPath: /etc/loki
            - name: storage
              mountPath: /data
          ports:
            - name: http-metrics
              containerPort: 3100
              protocol: TCP
          livenessProbe:
            httpGet: 
              path: /ready
              port: http-metrics
              scheme: HTTP
            initialDelaySeconds: 45
          readinessProbe:
            httpGet: 
              path: /ready
              port: http-metrics
              scheme: HTTP
            initialDelaySeconds: 45
          securityContext:
            readOnlyRootFilesystem: true
      terminationGracePeriodSeconds: 4800
      volumes:
        - name: config
          configMap:
            name: loki
        - name: storage
          hostPath:
            path: /app/loki
END
[root@k8s-master01 ~]# kubectl create -f loki-statefulset.yaml

2.安装 Promtail

1）创建 RBAC 授权文件

[root@k8s-master01 ~]# cat <<END > promtail-rbac.yaml
apiVersion: v1
kind: ServiceAccount
metadata:
  name: loki-promtail
  labels:
    app: promtail
  namespace: logging 
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  labels:
    app: promtail
  name: promtail-clusterrole
  namespace: logging
rules:
- apiGroups: [""]
  resources: ["nodes","nodes/proxy","services","endpoints","pods"]
  verbs: ["get", "watch", "list"] 
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
  name: promtail-clusterrolebinding
  labels:
    app: promtail
  namespace: logging
subjects:
  - kind: ServiceAccount
    name: loki-promtail
    namespace: logging
roleRef:
  kind: ClusterRole
  name: promtail-clusterrole
  apiGroup: rbac.authorization.k8s.io
END
[root@k8s-master01 ~]# kubectl create -f promtail-rbac.yaml

2）创建 ConfigMap 文件

Promtail 配置文件：官方介绍

[root@k8s-master01 ~]# cat <<"END" > promtail-configmap.yaml
apiVersion: v1
kind: ConfigMap
metadata:
  name: loki-promtail
  namespace: logging
  labels:
    app: promtail
data:
  promtail.yaml: |
    client:
      backoff_config:
        max_period: 5m 
        max_retries: 10
        min_period: 500ms
      batchsize: 1048576
      batchwait: 1s
      external_labels: 
      timeout: 10s
    positions:
      filename: /run/promtail/positions.yaml
    server:
      http_listen_port: 3101
    target_config:
      sync_period: 10s
    scrape_configs:
    - job_name: kubernetes-pods-name
      pipeline_stages:
        - docker: 
      kubernetes_sd_configs:
      - role: pod
      relabel_configs:
      - source_labels:
        - __meta_kubernetes_pod_label_name
        target_label: __service__
      - source_labels:
        - __meta_kubernetes_pod_node_name
        target_label: __host__
      - action: drop
        regex: ''
        source_labels:
        - __service__
      - action: labelmap
        regex: __meta_kubernetes_pod_label_(.+)
      - action: replace
        replacement: $1
        separator: /
        source_labels:
        - __meta_kubernetes_namespace
        - __service__
        target_label: job
      - action: replace
        source_labels:
        - __meta_kubernetes_namespace
        target_label: namespace
      - action: replace
        source_labels:
        - __meta_kubernetes_pod_name
        target_label: pod
      - action: replace
        source_labels:
        - __meta_kubernetes_pod_container_name
        target_label: container
      - replacement: /var/log/pods/*$1/*.log
        separator: /
        source_labels:
        - __meta_kubernetes_pod_uid
        - __meta_kubernetes_pod_container_name
        target_label: __path__
    - job_name: kubernetes-pods-app
      pipeline_stages:
        - docker: 
      kubernetes_sd_configs:
      - role: pod
      relabel_configs:
      - action: drop
        regex: .+
        source_labels:
        - __meta_kubernetes_pod_label_name
      - source_labels:
        - __meta_kubernetes_pod_label_app
        target_label: __service__
      - source_labels:
        - __meta_kubernetes_pod_node_name
        target_label: __host__
      - action: drop
        regex: ''
        source_labels:
        - __service__
      - action: labelmap
        regex: __meta_kubernetes_pod_label_(.+)
      - action: replace
        replacement: $1
        separator: /
        source_labels:
        - __meta_kubernetes_namespace
        - __service__
        target_label: job
      - action: replace
        source_labels:
        - __meta_kubernetes_namespace
        target_label: namespace
      - action: replace
        source_labels:
        - __meta_kubernetes_pod_name
        target_label: pod
      - action: replace
        source_labels:
        - __meta_kubernetes_pod_container_name
        target_label: container
      - replacement: /var/log/pods/*$1/*.log
        separator: /
        source_labels:
        - __meta_kubernetes_pod_uid
        - __meta_kubernetes_pod_container_name
        target_label: __path__
    - job_name: kubernetes-pods-direct-controllers
      pipeline_stages:
        - docker: 
      kubernetes_sd_configs:
      - role: pod
      relabel_configs:
      - action: drop
        regex: .+
        separator: ''
        source_labels:
        - __meta_kubernetes_pod_label_name
        - __meta_kubernetes_pod_label_app
      - action: drop
        regex: '[0-9a-z-.]+-[0-9a-f]8,10'
        source_labels:
        - __meta_kubernetes_pod_controller_name
      - source_labels:
        - __meta_kubernetes_pod_controller_name
        target_label: __service__
      - source_labels:
        - __meta_kubernetes_pod_node_name
        target_label: __host__
      - action: drop
        regex: ''
        source_labels:
        - __service__
      - action: labelmap
        regex: __meta_kubernetes_pod_label_(.+)
      - action: replace
        replacement: $1
        separator: /
        source_labels:
        - __meta_kubernetes_namespace
        - __service__
        target_label: job
      - action: replace
        source_labels:
        - __meta_kubernetes_namespace
        target_label: namespace
      - action: replace
        source_labels:
        - __meta_kubernetes_pod_name
        target_label: pod
      - action: replace
        source_labels:
        - __meta_kubernetes_pod_container_name
        target_label: container
      - replacement: /var/log/pods/*$1/*.log
        separator: /
        source_labels:
        - __meta_kubernetes_pod_uid
        - __meta_kubernetes_pod_container_name
        target_label: __path__
    - job_name: kubernetes-pods-indirect-controller
      pipeline_stages:
        - docker: 
      kubernetes_sd_configs:
      - role: pod
      relabel_configs:
      - action: drop
        regex: .+
        separator: ''
        source_labels:
        - __meta_kubernetes_pod_label_name
        - __meta_kubernetes_pod_label_app
      - action: keep
        regex: '[0-9a-z-.]+-[0-9a-f]8,10'
        source_labels:
        - __meta_kubernetes_pod_controller_name
      - action: replace
        regex: '([0-9a-z-.]+)-[0-9a-f]8,10'
        source_labels（十三）：如何用 Loki 收集查看 Kubernetes Events
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