Loki

---
name: loki
license: Apache-2.0
description: >
  Grafana Loki log aggregation and LogQL query language. Covers LogQL syntax (log queries, metric queries,
  label matchers, line filters, parsers: json/logfmt/pattern/regexp/unpack, label filters, line_format),
  Loki architecture, log ingestion via Alloy/Promtail/Fluent Bit, structured metadata, and Logs Drilldown.
  Use when writing LogQL queries, configuring Loki, troubleshooting log pipelines, or analyzing logs.
---

# Grafana Loki - Log Aggregation

> **Docs**: https://grafana.com/docs/loki/latest/

Indexes only metadata (labels), not full log content — dramatically cheaper than full-text search systems.

## LogQL Quick Reference

### Log Stream Selector (required in every query)

```logql
{app="nginx"}                        # exact match
{app!="nginx"}                       # not equal
{app=~"nginx|apache"}               # regex match
{app!~"debug.*"}                     # regex not match… install to load the full skill