1.Loki简介

Loki是受Prometheus启发由Grafana Labs团队开源的水平可扩展，高度可用的多租户日志聚合系统。 开发语言: Google Go。它的设计具有很高的成本效益，并且易于操作。使用标签来作为索引，而不是对全文进行检索，也就是说，你通过这些标签既可以查询日志的内容也可以查询到监控的数据签，极大地降低了日志索引的存储。系统架构十分简单，由以下3个部分组成 ：

• Loki 是主服务器，负责存储日志和处理查询 。
• promtail 是代理，负责收集日志并将其发送给 loki 。
• Grafana 用于 UI 展示。

只要在应用程序服务器上安装promtail来收集日志然后发送给Loki存储，就可以在Grafana UI界面通过添加Loki为数据源进行日志查询（如果Loki服务器性能不够，可以部署多个Loki进行存储及查询）。作为一个日志系统不光只有查询分析日志的能力，还能对日志进行监控和报警。

Loki文档网址：https://grafana.com/docs/loki/latest/

下载网址：https://github.com/grafana/loki/releases

2.Loki的部署

• promtail收集并将日志发送给loki的 Distributor 组件
• Distributor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到Ingester
• Ingester接受日志流并构建数据块，压缩后存放到所连接的存储后端
• Querier 收到HTTP查询请求，并将请求发送至Ingester 用以获取内存数据 ，Ingester 收到请求后返回符合条件的数据 ；
• 如果 Ingester 没有返回数据，Querier 会从后端存储加载数据并遍历去重执行查询 ，通过HTTP返回查询结果
  
  先将loki-linux-amd64.zip 和promtail-linux-amd64.zip和上传到服务器，启动loki服务

#创建存放loki数据的目录
mkdir  /data/loki/{chunks,index}  -p

#创建loki的部署目录
mkdir /usr/local/loki

#编辑config.yaml问价，内容如下
auth_enabled: false
server:
  http_listen_port: 3100
ingester:
  lifecycler:
    address: 47.104.76.227
    ring:
      kvstore:
        store: inmemory
      replication_factor: 1
    final_sleep: 0s
  chunk_idle_period: 5m
  chunk_retain_period: 30s

schema_config:
  configs:
  - from: 2022-12-16
    store: boltdb
    object_store: filesystem
    schema: v11
    index:
      prefix: index_
      period: 168h   #每张表的时间范围7天

storage_config:
  boltdb:
    directory: /data/loki/index   #索引文件存储地址

  filesystem:
    directory: /data/loki/chunks  #块存储地址

limits_config:
  enforce_metric_name: false
  reject_old_samples: true
  reject_old_samples_max_age: 168h


chunk_store_config:
# 最大可查询历史日期 28天,这个时间必须是schema_config中的period的倍数，否则报错。
  max_look_back_period: 672h
# 表的保留期28天
table_manager:
  retention_deletes_enabled: true
  retention_period: 672h


# 启动loki服务
nohup ./loki-linux-amd64 -config.file=./config.yaml >./loki.log 2>&1 &

解压promtail并启动

#创建promtail的部署目录
mkdir /usr/local/promtail -p

#编辑promtail.yaml问价，内容如下
server:
  http_listen_port: 9080
  grpc_listen_port: 0

positions:
  filename: ./positions.yaml
  ignore_invalid_yaml: true

clients:
  - url: http://47.104.76.227:3100/loki/api/v1/push

scrape_configs:
#ucenter1
 - job_name: loki_log
   file_sd_configs:
     - files:
       - ./conf/*.yaml
       refresh_interval: 1m
[root@cxcc01 promtail]# tree conf/
conf/
└── log.yaml

0 directories, 1 file
[root@cxcc01 promtail]# cat conf/log.yaml 
- targets:
    - 47.104.76.227
  labels:
    host: 47.104.76.227
    __path__: /var/log/messages
- targets:
    - 47.104.76.227
  labels:
    host: 47.104.76.227
    __path__: /var/log/secure

#启动服务
nohup ./promtail-linux-amd64 -config.file=./promtail.yaml > ./promtail.log 2>&1 &

3.grafana展示

上图可以看到两个文件的日志信息已经采集并展示。其中导航栏中右侧还是支持搜索的功能

4.日志的dashboard文件

{
  "annotations": {
    "list": [
      {
        "builtIn": 1,
        "datasource": {
          "type": "datasource",
          "uid": "grafana"
        },
        "enable": true,
        "hide": true,
        "iconColor": "rgba(0, 211, 255, 1)",
        "name": "Annotations & Alerts",
        "target": {
          "limit": 100,
          "matchAny": false,
          "tags": [],
          "type": "dashboard"
        },
        "type": "dashboard"
      }
    ]
  },
  "editable": true,
  "fiscalYearStartMonth": 0,
  "graphTooltip": 0,
  "id": 3,
  "iteration": 1671275851848,
  "links": [],
  "liveNow": false,
  "panels": [
    {
      "aliasColors": {},
      "bars": false,
      "dashLength": 10,
      "dashes": false,
      "datasource": {
        "type": "loki",
        "uid": "${ENV}"
      },
      "fill": 1,
      "fillGradient": 0,
      "gridPos": {
        "h": 5,
        "w": 24,
        "x": 0,
        "y": 0
      },
      "hiddenSeries": false,
      "id": 4,
      "legend": {
        "alignAsTable": true,
        "avg": false,
        "current": false,
        "max": false,
        "min": false,
        "rightSide": true,
        "show": true,
        "total": false,
        "values": false
      },
      "lines": true,
      "linewidth": 1,
      "nullPointMode": "null",
      "options": {
        "alertThreshold": true
      },
      "percentage": false,
      "pluginVersion": "8.5.10",
      "pointradius": 2,
      "points": false,
      "renderer": "flot",
      "seriesOverrides": [],
      "spaceLength": 10,
      "stack": false,
      "steppedLine": false,
      "targets": [
        {
          "datasource": {
            "type": "loki",
            "uid": "2NkA815Vk"
          },
          "expr": "sum (count_over_time({filename=~\"$log\",host=~\"$host\"}[2m] )) by (host,filename)",
          "hide": false,
          "legendFormat": "{{host}}=={{filename}}",
          "refId": "B"
        }
      ],
      "thresholds": [],
      "timeRegions": [],
      "title": "日志量统计",
      "tooltip": {
        "shared": true,
        "sort": 0,
        "value_type": "individual"
      },
      "type": "graph",
      "xaxis": {
        "mode": "time",
        "show": true,
        "values": []
      },
      "yaxes": [
        {
          "$$hashKey": "object:319",
          "format": "short",
          "logBase": 1,
          "show": true
        },
        {
          "$$hashKey": "object:320",
          "format": "short",
          "logBase": 1,
          "show": true
        }
      ],
      "yaxis": {
        "align": false
      }
    },
    {
      "datasource": {
        "type": "loki",
        "uid": "2NkA815Vk"
      },
      "description": "",
      "gridPos": {
        "h": 21,
        "w": 24,
        "x": 0,
        "y": 5
      },
      "id": 2,
      "options": {
        "dedupStrategy": "exact",
        "enableLogDetails": false,
        "prettifyLogMessage": false,
        "showCommonLabels": false,
        "showLabels": false,
        "showTime": true,
        "sortOrder": "Descending",
        "wrapLogMessage": true
      },
      "pluginVersion": "7.4.3",
      "targets": [
        {
          "datasource": {
            "type": "loki",
            "uid": "2NkA815Vk"
          },
          "expr": "{filename=~\"$log\",host=~\"$host\"}|~ \"(?i)$log_level\"",
          "hide": false,
          "maxLines": 100,
          "refId": "C"
        }
      ],
      "title": "日志",
      "transparent": true,
      "type": "logs"
    }
  ],
  "refresh": "",
  "schemaVersion": 36,
  "style": "dark",
  "tags": [
    "ELK"
  ],
  "templating": {
    "list": [
      {
        "current": {
          "selected": false,
          "text": "Loki",
          "value": "Loki"
        },
        "hide": 0,
        "includeAll": false,
        "label": "选择环境",
        "multi": false,
        "name": "ENV",
        "options": [],
        "query": "loki",
        "queryValue": "",
        "refresh": 1,
        "regex": "",
        "skipUrlSync": false,
        "type": "datasource"
      },
      {
        "current": {
          "selected": true,
          "text": "/var/log/messages",
          "value": "/var/log/messages"
        },
        "datasource": {
          "type": "loki",
          "uid": "2NkA815Vk"
        },
        "definition": "label_values({},filename)",
        "hide": 0,
        "includeAll": false,
        "label": "日志",
        "multi": false,
        "name": "log",
        "options": [],
        "query": "label_values({},filename)",
        "refresh": 1,
        "regex": "",
        "skipUrlSync": false,
        "sort": 1,
        "type": "query"
      },
      {
        "current": {
          "selected": false,
          "text": "47.104.76.227",
          "value": "47.104.76.227"
        },
        "datasource": {
          "type": "loki",
          "uid": "2NkA815Vk"
        },
        "definition": "label_values({},host)",
        "hide": 0,
        "includeAll": false,
        "label": "主机IP",
        "multi": false,
        "name": "host",
        "options": [],
        "query": "label_values({},host)",
        "refresh": 1,
        "regex": "",
        "skipUrlSync": false,
        "sort": 1,
        "type": "query"
      },
      {
        "allValue": "(^\\\\S|^\\\\s)",
        "current": {
          "selected": false,
          "text": "All",
          "value": "$__all"
        },
        "description": "可以直接输入搜索的关键字进行过滤",
        "hide": 0,
        "includeAll": true,
        "label": "关键字过滤",
        "multi": false,
        "name": "log_level",
        "options": [
          {
            "selected": true,
            "text": "All",
            "value": "$__all"
          },
          {
            "selected": false,
            "text": "warning",
            "value": "warning"
          },
          {
            "selected": false,
            "text": "unknown",
            "value": "unknown"
          },
          {
            "selected": false,
            "text": "info",
            "value": "info"
          },
          {
            "selected": false,
            "text": "error",
            "value": "error"
          },
          {
            "selected": false,
            "text": "直接输入关键字搜索",
            "value": "直接输入关键字搜索"
          }
        ],
        "query": "warning,unknown,info,error,直接输入关键字搜索",
        "queryValue": "",
        "skipUrlSync": false,
        "type": "custom"
      }
    ]
  },
  "time": {
    "from": "now-1h",
    "to": "now"
  },
  "timepicker": {},
  "timezone": "",
  "title": "loki日志",
  "uid": "NlV_8QD7k",
  "version": 19,
  "weekStart": ""
}