為什么使用 Loki

Loki 是一個輕量級的日志收集、分析的應(yīng)用，采用的是 promtail 的方式來獲取日志內(nèi)容并送到 loki 里面進(jìn)行存儲，最終在 grafana 的 datasource 里面添加數(shù)據(jù)源進(jìn)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(yōu)點(diǎn)：

支持的客戶端，如 Promtail，F(xiàn)luentbit，F(xiàn)luentd，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(qū)動程序等

沒有日志格式要求，包括 JSON，XML，CSV，logfmt，非結(jié)構(gòu)化文本

使用與查詢指標(biāo)相同的語法查詢?nèi)罩?/p>

日志查詢時允許動態(tài)篩選和轉(zhuǎn)換日志行

可以輕松地計(jì)算日志中的需要的指標(biāo)

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

云原生支持，使用 Prometheus 形式抓取數(shù)據(jù)

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(nèi)容。具體查詢效果如下：

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

日志搜集架構(gòu)

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(jié)點(diǎn)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(jié)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(wù)啟動后，我們做的數(shù)據(jù)查詢、數(shù)據(jù)寫入都是來自這一個節(jié)點(diǎn)。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(yùn)行時 fronted-query 查詢會將流量轉(zhuǎn)發(fā)到 read 節(jié)點(diǎn)上。讀節(jié)點(diǎn)上保留了querier、ruler、fronted，寫節(jié)點(diǎn)上保留了distributor、ingester。

微服務(wù)模式運(yùn)行

微服務(wù)模式運(yùn)行下，通過不同的配置參數(shù)啟動為不同的角色，每一個進(jìn)程都引用它的目標(biāo)角色服務(wù)。

大顯身手之服務(wù)端部署

上面講了那么多關(guān)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(xiàn)在你的腦海里。在部署之前你需要準(zhǔn)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(zhǔn)備一份。這里提供了一份完整的 allInOne 配置文件，部分內(nèi)容進(jìn)行了優(yōu)化。 以下配置文件內(nèi)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(nèi)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(chuàng)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(rèn)第一個網(wǎng)卡的名稱
    ## instance_interface_names
    ## instance_addr: 127.0.0.1
    ## 默認(rèn)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(fā)服務(wù)器、攝取器和查詢器之間發(fā)現(xiàn)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(huán)。
## 至少定義了1個join_members配置后，將自動為分發(fā)服務(wù)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(shí)例的情況下為 1

ingester.lifecycler.min_ready_duration的值為 15s，在啟動后默認(rèn)會顯示 15 秒將狀態(tài)變?yōu)?ready

memberlist.node_name的值可以不用設(shè)置，默認(rèn)是當(dāng)前主機(jī)的名稱

memberlist.join_members是一個列表，在有多個實(shí)例的情況下需要添加各個節(jié)點(diǎn)的主機(jī)名 /IP 地址。 在 k8s 里面可以設(shè)置成一個service綁定到 StatefulSets。

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

instance_interface_names是一個列表，默認(rèn)的為["en0","eth0"]，可以根據(jù)需要設(shè)置對應(yīng)的網(wǎng)卡名稱，一般不需要進(jìn)行特殊設(shè)置。

創(chuàng)建 configmap

說明：將上面的內(nèi)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(chuàng)建：

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

可以通過命令查看到已經(jīng)創(chuàng)建好的 configmap，具體操作詳見下圖

創(chuàng)建持久化存儲

在 k8s 里面我們的數(shù)據(jù)是需要進(jìn)行持久化的。Loki 收集起來的日志信息對于業(yè)務(wù)來說是至關(guān)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?yàn)闆]有對應(yīng)的環(huán)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(chuàng)建應(yīng)用
準(zhǔn)備好 k8s 的 StatefulSet 部署文件后就可以直接在集群里面創(chuàng)建應(yīng)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(yàn)證部署結(jié)果

當(dāng)看到上面的Running狀態(tài)時可以通過 API 的方式看一下分發(fā)器是不是正常工作，當(dāng)顯示Active時正常才會正常分發(fā)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