Alloy

Unified telemetry collector for logs, metrics, and traces.

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Overview

Alloy (successor to Promtail) collects and forwards telemetry data.

Property	Value
Image	grafana/alloy:v1.4.2
Container	alloy
Config	~/ravenhelm/services/alloy/

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Data Flow

Docker containers → Alloy → Loki (logs)
                         → Prometheus (metrics)
                         → Tempo (traces)

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Quick Commands

# View logs
docker logs -f alloy

# Restart
docker restart alloy

# Check config
docker exec alloy cat /etc/alloy/config.alloy

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Configuration

config.alloy

// Docker log discovery
loki.source.docker "containers" {
  host       = "unix:///var/run/docker.sock"
  targets    = discovery.docker.containers.targets
  forward_to = [loki.write.default.receiver]
}

// Send to Loki
loki.write "default" {
  endpoint {
    url = "http://loki:3100/loki/api/v1/push"
  }
}

// Docker container discovery
discovery.docker "containers" {
  host = "unix:///var/run/docker.sock"
}

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Troubleshooting

Issue: Logs Not Forwarding

Symptoms: Loki not receiving logs

Diagnosis:

docker logs alloy | grep -i error
docker exec alloy alloy fmt --check /etc/alloy/config.alloy

Solutions:

1. Verify Docker socket is mounted
2. Check Loki endpoint is reachable
3. Validate config syntax