[loki]轻量级日志聚合系统loki快速入门

前言

• 简述：loki是由grafana开源的日志聚合系统，相较于ELK、EFK更轻量。
• loki特性：
  • 不对日志进行全文索引。通过存储压缩非结构化日志和仅索引元数据，Loki 操作起来会更简单，更省成本。
  • 通过使用与 Prometheus 相同的标签记录流对日志进行索引和分组，这使得日志的扩展和操作效率更高，能对接 alertmanager；
  • 特别适合储存 Kubernetes Pod 日志；诸如 Pod 标签之类的元数据会被自动删除和编入索引；
  • Grafana原生支持
• 版本：
  • 系统：centos7
  • loki：2.6.1
  • promtail：2.6.1
  • grafana: 8.3.3

本文以loki监控nginx日志为例。nginx日志所在目录为 /home/admin/apps/nginx/logs/

安装loki

docker方式

PS: 未经测试

docker pull grafana/loki
wget https://raw.githubusercontent.com/grafana/loki/v2.6.1/cmd/loki/loki-local-config.yaml -O loki-config.yaml
docker run --name loki -d -v $(pwd):/mnt/config -p 3100:3100 grafana/loki:2.6.1 -config.file=/mnt/config/loki-config.yaml

二进制方式

1. 官方GitHub仓库的Release页下载压缩包并解压
2. 编辑loki-config.yaml

auth_enabled: false

server:
  http_listen_port: 3100
  grpc_listen_port: 9096

ingester:
  wal:
    enabled: true
    dir: /home/apps/loki/wal
  lifecycler:
    address: 127.0.0.1
    ring:
      kvstore:
        store: inmemory
      replication_factor: 1
    final_sleep: 0s
  chunk_idle_period: 1h       # Any chunk not receiving new logs in this time will be flushed
  max_chunk_age: 1h           # All chunks will be flushed when they hit this age, default is 1h
  chunk_target_size: 1048576  # Loki will attempt to build chunks up to 1.5MB, flushing first if chunk_idle_period or max_chunk_age is reached first
  chunk_retain_period: 30s    # Must be greater than index read cache TTL if using an index cache (Default index read cache TTL is 5m)
  max_transfer_retries: 0     # Chunk transfers disabled

schema_config:
  configs:
    - from: 2020-10-24
      store: boltdb-shipper
      object_store: filesystem
      schema: v11
      index:
        prefix: index_
        period: 24h

storage_config:
  boltdb_shipper:
    active_index_directory: /home/apps/loki/boltdb-shipper-active
    cache_location: /home/apps/loki/boltdb-shipper-cache
    cache_ttl: 24h         # Can be increased for faster performance over longer query periods, uses more disk space
    shared_store: filesystem
  filesystem:
    directory: /home/apps/loki/chunks

compactor:
  working_directory: /home/apps/loki/boltdb-shipper-compactor
  shared_store: filesystem

limits_config:
  reject_old_samples: true
  reject_old_samples_max_age: 168h

chunk_store_config:
  max_look_back_period: 0s

table_manager:
  retention_deletes_enabled: false
  retention_period: 0s

ruler:
  storage:
    type: local
    local:
      directory: /home/apps/loki/rules
  rule_path: /home/apps/loki/rules-temp
  alertmanager_url: http://localhost:9093
  ring:
    kvstore:
      store: inmemory
  enable_api: true

3. 启动

./loki -config.file=loki-config.yaml > /dev/null 2>&1 &

安装promtail

docker方式

PS: 未经测试

wget https://raw.githubusercontent.com/grafana/loki/v2.6.1/clients/cmd/promtail/promtail-docker-config.yaml -O promtail-config.yaml
docker run --name promtail -d -v $(pwd):/mnt/config -v /var/log:/var/log --link loki grafana/promtail:2.6.1 -config.file=/mnt/config/promtail-config.yaml

二进制方式

1. 官方GitHub仓库Release页下载压缩包并解压
2. 编辑promtail-config.yaml

server:
  http_listen_port: 9080
  grpc_listen_port: 0

positions:
  filename: /tmp/positions.yaml

clients:
  - url: http://192.168.2.249:3100/loki/api/v1/push

scrape_configs:
- job_name: nginx
  static_configs:
  - targets:
      - 192.168.2.249
    labels:
      job: varlogs
      __path__: /home/admin/apps/nginx/logs/*log

3. 启动

nohup ./promtail -config.file=promtail-config.yaml > /dev/null 2>&1 &

安装grafana

1. 创建容器并运行

docker pull 'grafana/grafana:latest'
docker run --name grafana -p 3000:3000 -d 'grafana/grafana:latest'

2. 浏览器访问ip:3000，账密默认为：admin/admin
3. 配置loki数据源

参考

• 微信公众号 - 高效运维 - 轻量级日志Loki全攻略，再也不会整懵了
• 知乎 - 平凡人笔记 - 轻量级日志系统Loki原理简介和使用
• 稀土掘金 - ik - Loki+Promtail+Grafana我们不是LSP