Parse JSON logs and reshape line

Filter by substring, parse JSON, render only chosen fields. note: | json before line_format.

{app="api"} |= "error" | json | line_format "{{.level}} {{.msg}}"
tool
loki7 commands
tags
lokilogqlobservabilitydebug

More loki commands

  • Per-level log rate
    sum by (level) (rate({app="api"} | logfmt [5m]))

    Logs/sec grouped by level over 5m window. modern: logfmt parser for key=value lines.

  • Quantile over unwrapped latency
    quantile_over_time(0.99, {app="api"} | json | unwrap latency_ms [5m]) by (route)

    p99 latency from a numeric log field per route. note: unwrap needs a numeric label/field.

  • Count matching lines over time
    sum(count_over_time({namespace="prod"} |~ "timeout|deadline exceeded" [1m]))

    Count regex-matched error lines per minute across a namespace. |~ is regex match.

  • logcli ad-hoc query
    logcli query '{job="app/api"} |= "panic"' --since=1h --limit=200 --output=jsonl

    CLI query for last hour with line cap and JSONL output. set LOKI_ADDR env first.

  • Loki query_range via API
    curl -sG "$LOKI_ADDR/loki/api/v1/query_range" --data-urlencode 'query=sum(rate({app="api"}[5m]))' --data-urlencode 'step=60' | jq '.data.result'

    Run a range metric query over HTTP and extract result with jq. step is in seconds.

all 7 loki commands