Grafana Loki

Aggregate and query logs with Grafana Loki, the Prometheus-inspired logging system.

When to Use This Skill

Use this skill when:

• Implementing cost-effective log aggregation
• Building logging for Kubernetes environments
• Integrating logs with Grafana dashboards
• Querying logs with label-based filtering
• Preferring lighter-weight alternative to ELK

Prerequisites

• Docker or Kubernetes
• Grafana for visualization
• Promtail or other log shipper

Architecture Overview

┌─────────────┐     ┌──────────┐     ┌──────────┐
│ Application │────▶│ Promtail │────▶│   Loki   │
└─────────────┘     └──────────┘     └──────────┘
                                          │
                                          ▼
                                     ┌──────────┐
                                     │ Grafana  │
                                     └──────────┘

Docker Deployment

# docker-compose.yml
version: '3.8'

services:
  loki:
    image: grafana/loki:2.9.0
    ports:
      - "3100:3100"
    volumes:
      - ./loki-config.yaml:/etc/loki/local-config.yaml
      - loki-data:/loki
    command: -config.file=/etc/loki/local-config.yaml

  promtail:
    image: grafana/promtail:2.9.0
    volumes:
      - ./promtail-config.yaml:/etc/promtail/config.yaml
      - /var/log:/var/log:ro
      - /var/lib/docker/containers:/var/lib/docker/containers:ro
    command: -config.file=/etc/promtail/config.yaml

  grafana:
    image: grafana/grafana:10.2.0
    ports:
      - "3000:3000"
    volumes:
      - grafana-data:/var/lib/grafana
      - ./grafana/provisioning:/etc/grafana/provisioning
    environment:
      - GF_AUTH_ANONYMOUS_ENABLED=true
      - GF_AUTH_ANONYMOUS_ORG_ROLE=Admin

volumes:
  loki-data:
  grafana-data:

Loki Configuration

# loki-config.yaml
auth_enabled: false

server:
  http_listen_port: 3100