為什么使用 Loki

Loki 是一個輕量級的日志收集、分析的應用，采用的是 promtail 的方式來獲取日志內容并送到 loki 里面進行存儲，最終在 grafana 的 datasource 里面添加數據源進行日志的展示、查詢。 loki 的持久化存儲支持 azure、gcs、s3、swift、local 這 5 中類型，其中常用的是 s3、local。另外，它還支持很多種日志搜集類型，像最常用的 logstash、fluentbit 也在官方支持的列表中。

它有哪些優點：

支持的客戶端，如 Promtail，Fluentbit，Fluentd，Vector，Logstash 和 Grafana Agent

首選代理 Promtail，可以多來源提取日志，包括本地日志文件，systemd，Windows 事件日志，Docker 日志記錄驅動程序等

沒有日志格式要求，包括 JSON，XML，CSV，logfmt，非結構化文本

使用與查詢指標相同的語法查詢日志

日志查詢時允許動態篩選和轉換日志行

可以輕松地計算日志中的需要的指標

引入時的最小索引意味著您可以在查詢時動態地對日志進行切片和切塊，以便在出現新問題時回答它們

云原生支持，使用 Prometheus 形式抓取數據

各日志收集組件簡單對比：

Loki 的工作方式

從上面的圖中我們可以看到，它在解析日志的時候是以index為主的，index 包括時間戳和 pod 的部分 label（其他 label 為 filename、containers 等），其余的是日志內容。具體查詢效果如下：

{app=”loki”,namespace=”kube-public”}為索引。

日志搜集架構

在使用過程中，官方推薦使用 promtail 做為 agent 以 DaemonSet 方式部署在 kubernetes 的 worker 節點上搜集日志。另外也可以用上面提到的其他日志收集工具來收取，這篇文章在結尾處會附上其他工具的配置方式。

Loki 部署模式有哪些

all（讀寫模式）

服務啟動后，我們做的數據查詢、數據寫入都是來自這一個節點。請看下面的這個圖解：

read/write（讀寫分離模式）

在讀寫分離模式下運行時 fronted-query 查詢會將流量轉發到 read 節點上。讀節點上保留了querier、ruler、fronted，寫節點上保留了distributor、ingester。

微服務模式運行

微服務模式運行下，通過不同的配置參數啟動為不同的角色，每一個進程都引用它的目標角色服務。

大顯身手之服務端部署

上面講了那么多關于 loki 的介紹和它的工作模式，你一定期待它是怎么部署的吧？！該怎么部署、部署在哪里、部署后怎么使用等等問題都會出現在你的腦海里。在部署之前你需要準備好一個 k8s 集群才行哦。那好，接下來耐著性子往下看……

AllInOne 部署模式

k8s部署

我們從 github 上下載的程序是沒有配置文件的，需要提前將文件準備一份。這里提供了一份完整的 allInOne 配置文件，部分內容進行了優化。 以下配置文件內容特別長：

auth_enabled: false
target: all
ballast_bytes: 20480
server:
  grpc_listen_port: 9095
  http_listen_port: 3100
  graceful_shutdown_timeout: 20s
  grpc_listen_address: "0.0.0.0"
  grpc_listen_network: "tcp"
  grpc_server_max_concurrent_streams: 100
  grpc_server_max_recv_msg_size: 4194304
  grpc_server_max_send_msg_size: 4194304
  http_server_idle_timeout: 2m
  http_listen_address: "0.0.0.0"
  http_listen_network: "tcp"
  http_server_read_timeout: 30s
  http_server_write_timeout: 20s
  log_source_ips_enabled: true
  ## http_path_prefix如果需要更改，在推送日志的時候前綴都需要加指定的內容
  ## http_path_prefix: "/"
  register_instrumentation: true
  log_format: json
  log_level: info
distributor:
  ring:
    heartbeat_timeout: 3s
    kvstore:
      prefix: collectors/
      store: memberlist
      ## 需要提前創建好consul集群
    ##   consul:
    ##     http_client_timeout: 20s
    ##     consistent_reads: true
    ##     host: 127.0.0.1:8500
    ##     watch_burst_size: 2
    ##     watch_rate_limit: 2
querier:
  engine:
    max_look_back_period: 20s 
    timeout: 3m0s 
  extra_query_delay: 100ms 
  max_concurrent: 10 
  multi_tenant_queries_enabled: true
  query_ingester_only: false
  query_ingesters_within: 3h0m0s
  query_store_only: false
  query_timeout: 5m0s
  tail_max_duration: 1h0s
query_scheduler:
  max_outstanding_requests_per_tenant: 2048
  grpc_client_config:
    max_recv_msg_size: 104857600
    max_send_msg_size: 16777216
    grpc_compression: gzip
    rate_limit: 0
    rate_limit_burst: 0
    backoff_on_ratelimits: false
    backoff_config:
      min_period: 50ms
      max_period: 15s
      max_retries: 5 
  use_scheduler_ring: true
  scheduler_ring:
    kvstore:
      store: memberlist
      prefix: "collectors/"
    heartbeat_period: 30s
    heartbeat_timeout: 1m0s
    ## 默認第一個網卡的名稱
    ## instance_interface_names
    ## instance_addr: 127.0.0.1
    ## 默認server.grpc-listen-port
    instance_port: 9095
frontend:
  max_outstanding_per_tenant: 4096
  querier_forget_delay: 1h0s
  compress_responses: true
  log_queries_longer_than: 2m0s
  max_body_size: 104857600
  query_stats_enabled: true
  scheduler_dns_lookup_period: 10s 
  scheduler_worker_concurrency: 15
query_range:
  align_queries_with_step: true
  cache_results: true
  parallelise_shardable_queries: true
  max_retries: 3
  results_cache:
    cache:
      enable_fifocache: false
      default_validity: 30s 
      background:
        writeback_buffer: 10000
      redis:
        endpoint: 127.0.0.1:6379
        timeout: 1s
        expiration: 0s 
        db: 9
        pool_size: 128 
        password: 1521Qyx6^
        tls_enabled: false
        tls_insecure_skip_verify: true
        idle_timeout: 10s 
        max_connection_age: 8h
ruler:
  enable_api: true
  enable_sharding: true
  alertmanager_refresh_interval: 1m
  disable_rule_group_label: false
  evaluation_interval: 1m0s
  flush_period: 3m0s
  for_grace_period: 20m0s
  for_outage_tolerance: 1h0s
  notification_queue_capacity: 10000
  notification_timeout: 4s
  poll_interval: 10m0s
  query_stats_enabled: true
  remote_write:
    config_refresh_period: 10s
    enabled: false
  resend_delay: 2m0s
  rule_path: /rulers
  search_pending_for: 5m0s
  storage:
    local:
      directory: /data/loki/rulers
    type: configdb
  sharding_strategy: default
  wal_cleaner:
    period:  240h
    min_age: 12h0m0s
  wal:
    dir: /data/loki/ruler_wal
    max_age: 4h0m0s
    min_age: 5m0s
    truncate_frequency: 1h0m0s
  ring:
    kvstore:
      store: memberlist
      prefix: "collectors/"
    heartbeat_period: 5s
    heartbeat_timeout: 1m0s
    ## instance_addr: "127.0.0.1"
    ## instance_id: "miyamoto.en0"
    ## instance_interface_names: ["en0","lo0"]
    instance_port: 9500
    num_tokens: 100
ingester_client:
  pool_config:
    health_check_ingesters: false
    client_cleanup_period: 10s 
    remote_timeout: 3s
  remote_timeout: 5s 
ingester:
  autoforget_unhealthy: true
  chunk_encoding: gzip
  chunk_target_size: 1572864
  max_transfer_retries: 0
  sync_min_utilization: 3.5
  sync_period: 20s
  flush_check_period: 30s 
  flush_op_timeout: 10m0s
  chunk_retain_period: 1m30s
  chunk_block_size: 262144
  chunk_idle_period: 1h0s
  max_returned_stream_errors: 20
  concurrent_flushes: 3
  index_shards: 32
  max_chunk_age: 2h0m0s
  query_store_max_look_back_period: 3h30m30s
  wal:
    enabled: true
    dir: /data/loki/wal 
    flush_on_shutdown: true
    checkpoint_duration: 15m
    replay_memory_ceiling: 2GB
  lifecycler:
    ring:
      kvstore:
        store: memberlist
        prefix: "collectors/"
      heartbeat_timeout: 30s 
      replication_factor: 1
    num_tokens: 128
    heartbeat_period: 5s 
    join_after: 5s 
    observe_period: 1m0s
    ## interface_names: ["en0","lo0"]
    final_sleep: 10s 
    min_ready_duration: 15s
storage_config:
  boltdb:
    directory: /data/loki/boltdb 
  boltdb_shipper:
    active_index_directory: /data/loki/active_index
    build_per_tenant_index: true
    cache_location: /data/loki/cache 
    cache_ttl: 48h
    resync_interval: 5m
    query_ready_num_days: 5
    index_gateway_client:
      grpc_client_config:
  filesystem:
    directory: /data/loki/chunks
chunk_store_config:
  chunk_cache_config:
    enable_fifocache: true
    default_validity: 30s
    background:
      writeback_buffer: 10000
    redis:
      endpoint: 192.168.3.56:6379
      timeout: 1s
      expiration: 0s 
      db: 8 
      pool_size: 128 
      password: 1521Qyx6^
      tls_enabled: false
      tls_insecure_skip_verify: true
      idle_timeout: 10s 
      max_connection_age: 8h
    fifocache:
      ttl: 1h
      validity: 30m0s
      max_size_items: 2000
      max_size_bytes: 500MB
  write_dedupe_cache_config:
    enable_fifocache: true
    default_validity: 30s 
    background:
      writeback_buffer: 10000
    redis:
      endpoint: 127.0.0.1:6379
      timeout: 1s
      expiration: 0s 
      db: 7
      pool_size: 128 
      password: 1521Qyx6^
      tls_enabled: false
      tls_insecure_skip_verify: true
      idle_timeout: 10s 
      max_connection_age: 8h
    fifocache:
      ttl: 1h
      validity: 30m0s
      max_size_items: 2000
      max_size_bytes: 500MB
  cache_lookups_older_than: 10s 
## 壓縮碎片索引
compactor:
  shared_store: filesystem
  shared_store_key_prefix: index/
  working_directory: /data/loki/compactor
  compaction_interval: 10m0s
  retention_enabled: true
  retention_delete_delay: 2h0m0s
  retention_delete_worker_count: 150
  delete_request_cancel_period: 24h0m0s
  max_compaction_parallelism: 2
  ## compactor_ring:
frontend_worker:
  match_max_concurrent: true
  parallelism: 10
  dns_lookup_duration: 5s 
## runtime_config 這里沒有配置任何信息
## runtime_config:
common:
  storage:
    filesystem:
      chunks_directory: /data/loki/chunks
      fules_directory: /data/loki/rulers
  replication_factor: 3
  persist_tokens: false
  ## instance_interface_names: ["en0","eth0","ens33"]
analytics:
  reporting_enabled: false
limits_config:
  ingestion_rate_strategy: global
  ingestion_rate_mb: 100
  ingestion_burst_size_mb: 18
  max_label_name_length: 2096
  max_label_value_length: 2048
  max_label_names_per_series: 60
  enforce_metric_name: true
  max_entries_limit_per_query: 5000
  reject_old_samples: true
  reject_old_samples_max_age: 168h
  creation_grace_period: 20m0s
  max_global_streams_per_user: 5000
  unordered_writes: true
  max_chunks_per_query: 200000
  max_query_length: 721h
  max_query_parallelism: 64 
  max_query_series: 700
  cardinality_limit: 100000
  max_streams_matchers_per_query: 1000 
  max_concurrent_tail_requests: 10 
  ruler_evaluation_delay_duration: 3s 
  ruler_max_rules_per_rule_group: 0
  ruler_max_rule_groups_per_tenant: 0
  retention_period: 700h
  per_tenant_override_period: 20s 
  max_cache_freshness_per_query: 2m0s
  max_queriers_per_tenant: 0
  per_stream_rate_limit: 6MB
  per_stream_rate_limit_burst: 50MB
  max_query_lookback: 0
  ruler_remote_write_disabled: false
  min_sharding_lookback: 0s
  split_queries_by_interval: 10m0s
  max_line_size: 30mb
  max_line_size_truncate: false
  max_streams_per_user: 0


## memberlist_conig模塊配置gossip用于在分發服務器、攝取器和查詢器之間發現和連接。
## 所有三個組件的配置都是唯一的，以確保單個共享環。
## 至少定義了1個join_members配置后，將自動為分發服務器、攝取器和ring 配置memberlist類型的kvstore
memberlist:
  randomize_node_name: true
  stream_timeout: 5s 
  retransmit_factor: 4
  join_members:
  - 'loki-memberlist'
  abort_if_cluster_join_fails: true
  advertise_addr: 0.0.0.0
  advertise_port: 7946
  bind_addr: ["0.0.0.0"]
  bind_port: 7946
  compression_enabled: true
  dead_node_reclaim_time: 30s
  gossip_interval: 100ms
  gossip_nodes: 3
  gossip_to_dead_nodes_time: 3
  ## join:
  leave_timeout: 15s
  left_ingesters_timeout: 3m0s 
  max_join_backoff: 1m0s
  max_join_retries: 5
  message_history_buffer_bytes: 4096
  min_join_backoff: 2s
  ## node_name: miyamoto
  packet_dial_timeout: 5s
  packet_write_timeout: 5s 
  pull_push_interval: 100ms
  rejoin_interval: 10s
  tls_enabled: false
  tls_insecure_skip_verify: true
schema_config:
  configs:
  - from: "2020-10-24"
    index:
      period: 24h
      prefix: index_
    object_store: filesystem
    schema: v11
    store: boltdb-shipper
    chunks:
      period: 168h
    row_shards: 32
table_manager:
  retention_deletes_enabled: false
  retention_period: 0s
  throughput_updates_disabled: false
  poll_interval: 3m0s
  creation_grace_period: 20m
  index_tables_provisioning:
    provisioned_write_throughput: 1000
    provisioned_read_throughput: 500
    inactive_write_throughput: 4
    inactive_read_throughput: 300
    inactive_write_scale_lastn: 50 
    enable_inactive_throughput_on_demand_mode: true
    enable_ondemand_throughput_mode: true
    inactive_read_scale_lastn: 10 
    write_scale:
      enabled: true
      target: 80
      ## role_arn:
      out_cooldown: 1800
      min_capacity: 3000
      max_capacity: 6000
      in_cooldown: 1800
    inactive_write_scale:
      enabled: true
      target: 80
      out_cooldown: 1800
      min_capacity: 3000
      max_capacity: 6000
      in_cooldown: 1800
    read_scale:
      enabled: true
      target: 80
      out_cooldown: 1800
      min_capacity: 3000
      max_capacity: 6000
      in_cooldown: 1800
    inactive_read_scale:
      enabled: true
      target: 80
      out_cooldown: 1800
      min_capacity: 3000
      max_capacity: 6000
      in_cooldown: 1800
  chunk_tables_provisioning:
    enable_inactive_throughput_on_demand_mode: true
    enable_ondemand_throughput_mode: true
    provisioned_write_throughput: 1000
    provisioned_read_throughput: 300
    inactive_write_throughput: 1
    inactive_write_scale_lastn: 50
    inactive_read_throughput: 300
    inactive_read_scale_lastn: 10
    write_scale:
      enabled: true
      target: 80
      out_cooldown: 1800
      min_capacity: 3000
      max_capacity: 6000
      in_cooldown: 1800
    inactive_write_scale:
      enabled: true
      target: 80
      out_cooldown: 1800
      min_capacity: 3000
      max_capacity: 6000
      in_cooldown: 1800
    read_scale:
      enabled: true
      target: 80
      out_cooldown: 1800
      min_capacity: 3000
      max_capacity: 6000
      in_cooldown: 1800
    inactive_read_scale:
      enabled: true
      target: 80
      out_cooldown: 1800
      min_capacity: 3000
      max_capacity: 6000
      in_cooldown: 1800
tracing:
  enabled: true

注意 :

ingester.lifecycler.ring.replication_factor的值在單實例的情況下為 1

ingester.lifecycler.min_ready_duration的值為 15s，在啟動后默認會顯示 15 秒將狀態變為 ready

memberlist.node_name的值可以不用設置，默認是當前主機的名稱

memberlist.join_members是一個列表，在有多個實例的情況下需要添加各個節點的主機名 /IP 地址。 在 k8s 里面可以設置成一個service綁定到 StatefulSets。

query_range.results_cache.cache.enable_fifocache建議設置為false，我這里設置成了 true

instance_interface_names是一個列表，默認的為["en0","eth0"]，可以根據需要設置對應的網卡名稱，一般不需要進行特殊設置。

創建 configmap

說明：將上面的內容寫入到一個文件loki-all.yaml，把它作為一個configmap寫入 k8s 集群。可以使用如下命令創建：

$ kubectl create configmap --from-file ./loki-all.yaml loki-all

可以通過命令查看到已經創建好的 configmap，具體操作詳見下圖

創建持久化存儲

在 k8s 里面我們的數據是需要進行持久化的。Loki 收集起來的日志信息對于業務來說是至關重要的，因此需要在容器重啟的時候日志能夠保留下來。那么就需要用到 pv、pvc，后端存儲可以使用 nfs、glusterfs、hostPath、azureDisk、cephfs 等 20 種支持類型，這里因為沒有對應的環境就采用了 hostPath 方式。

以下配置文件也特別長：

apiVersion: v1
kind: PersistentVolume
metadata:
  name: loki
  namespace: default
spec:
  hostPath:
    path: /glusterfs/loki
    type: DirectoryOrCreate
  capacity:
    storage: 1Gi
  accessModes:
    - ReadWriteMany
---
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: loki
  namespace: default
spec:
  accessModes:
    - ReadWriteMany
  resources:
    requests:
      storage: 1Gi
  volumeName: loki
創建應用
準備好 k8s 的 StatefulSet 部署文件后就可以直接在集群里面創建應用了。


apiVersion: apps/v1
kind: StatefulSet
metadata:
  labels:
    app: loki
  name: loki
  namespace: default
spec:
  podManagementPolicy: OrderedReady
  replicas: 1
  selector:
    matchLabels:
      app: loki
  template:
    metadata:
      annotations:
        prometheus.io/port: http-metrics
        prometheus.io/scrape: "true"
      labels:
        app: loki
    spec:
      containers:
      - args:
        - -config.file=/etc/loki/loki-all.yaml
        image: grafana/loki:2.5.0
        imagePullPolicy: IfNotPresent
        livenessProbe:
          failureThreshold: 3
          httpGet:
            path: /ready
            port: http-metrics
            scheme: HTTP
          initialDelaySeconds: 45
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 1
        name: loki
        ports:
        - containerPort: 3100
          name: http-metrics
          protocol: TCP
        - containerPort: 9095
          name: grpc
          protocol: TCP
        - containerPort: 7946
          name: memberlist-port
          protocol: TCP
        readinessProbe:
          failureThreshold: 3
          httpGet:
            path: /ready
            port: http-metrics
            scheme: HTTP
          initialDelaySeconds: 45
          periodSeconds: 10
          successThreshold: 1
          timeoutSeconds: 1
        resources:
          requests:
            cpu: 500m
            memory: 500Mi
          limits:
            cpu: 500m
            memory: 500Mi
        securityContext:
          readOnlyRootFilesystem: true
        volumeMounts:
        - mountPath: /etc/loki
          name: config
        - mountPath: /data
          name: storage
      restartPolicy: Always
      securityContext:
        fsGroup: 10001
        runAsGroup: 10001
        runAsNonRoot: true
        runAsUser: 10001
      serviceAccount: loki
      serviceAccountName: loki
      volumes:
      - emptyDir: {}
        name: tmp
      - name: config
        configMap:
          name: loki
      - persistentVolumeClaim:
          claimName: loki
        name: storage
---
kind: Service
apiVersion: v1
metadata:
  name: loki-memberlist
  namespace: default
spec:
  ports:
    - name: loki-memberlist
      protocol: TCP
      port: 7946
      targetPort: 7946
  selector:
    kubepi.org/name: loki
---
kind: Service
apiVersion: v1
metadata:
  name: loki
  namespace: default
spec:
  ports:
    - name: loki
      protocol: TCP
      port: 3100
      targetPort: 3100
  selector:
    kubepi.org/name: loki

驗證部署結果

當看到上面的Running狀態時可以通過 API 的方式看一下分發器是不是正常工作，當顯示Active時正常才會正常分發日志流到收集器（ingester)。

限于篇幅，更多部署方式，就不介紹了。

鏈接：https://juejin.cn/post/7150469420605767717

審核編輯：劉清