Loki

Log aggregation system optimized for Grafana.

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Overview

Loki collects and indexes logs from all containers via Alloy.

Property	Value
Image	grafana/loki:3.0.0
Container	loki
Port	3100 (internal)
Config	~/ravenhelm/services/loki/
Data	~/ravenhelm/data/loki/

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Quick Commands

# View logs
docker logs -f loki

# Restart
docker restart loki

# Check ready
curl http://localhost:3100/ready

# Query labels
curl http://localhost:3100/loki/api/v1/labels

# Query logs
curl -G http://localhost:3100/loki/api/v1/query_range \
  --data-urlencode 'query={container="traefik"}' \
  --data-urlencode 'limit=10'

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Log Labels

Label	Description
container	Container name
job	Job name (e.g., "containers")
host	Source host
level	Log level (if parsed)

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Common Queries (LogQL)

# All container logs
{job="containers"}

# Specific container
{container="norns-agent"}

# Filter by content
{container="traefik"} |= "error"

# JSON parsing
{container="norns-agent"} | json | level="error"

# Rate of errors
rate({container="traefik"} |= "error" [5m])

# Top 10 error messages
topk(10, sum by (message) (count_over_time({job="containers"} |= "error" | json [1h])))

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Configuration

loki-config.yaml

auth_enabled: false

server:
  http_listen_port: 3100

common:
  path_prefix: /loki
  storage:
    filesystem:
      chunks_directory: /loki/chunks
      rules_directory: /loki/rules
  replication_factor: 1
  ring:
    kvstore:
      store: inmemory

schema_config:
  configs:
    - from: 2020-10-24
      store: tsdb
      object_store: filesystem
      schema: v13
      index:
        prefix: index_
        period: 24h

limits_config:
  retention_period: 30d

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Troubleshooting

Issue: No Logs Appearing

Symptoms: Grafana shows no logs from Loki

Diagnosis:

# Check Loki is receiving logs
curl http://localhost:3100/loki/api/v1/labels

# Check Alloy is forwarding
docker logs alloy | grep loki

Solutions:

1. Verify Alloy is running and configured
2. Check network connectivity to Loki
3. Verify log labels match query