integration with prometheus and loki

🔗 Grafana Alloy Integration with Prometheus & Loki

This guide covers how to integrate Grafana Alloy with Prometheus for metrics and Loki for logs on Linux systems. 🎯

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📊 Prometheus Integration (Metrics)

To enable Prometheus to scrape Alloy's metrics, follow these steps:

✅ Step 1: Add Prometheus Exporter Block in Alloy

prometheus.exporter "alloy" {
  listen_address = "127.0.0.1:12345"
}

This allows Prometheus to scrape metrics from Alloy on port 12345.

✅ Step 2: Update Prometheus Config (prometheus.yml)

- job_name: 'alloy'
  static_configs:
    - targets: ['127.0.0.1:12345']
  relabel_configs:
    - source_labels: [__address__]
      regex: '.*'
      target_label: instance
      replacement: 'UAT: abc'

Prometheus will now collect Alloy metrics and label them as coming from UAT: abc. 🧠

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📄 Loki Integration (Logs)

To collect and send logs to Loki, configure the following pipeline in your Alloy config:

prometheus.exporter "alloy" {
  listen_address = "127.0.0.1:12345"
}

local.file_match "syslog" {
  path_targets = [{ __path__ = "/var/log/syslog" }]
}

loki.source.file "syslog" {
  targets    = local.file_match.syslog.targets
  forward_to = [loki.process.default.receiver]
}

loki.process "default" {
  stage.static_labels = {
    job  = "syslog"
    host = "uat-abc"
  }

  forward_to = [loki.write.default.receiver]
}

loki.write "default" {
  endpoint {
    url = "http://<loki_host>:3100/loki/api/v1/push"
  }
}

🚨 Note: Replace http://<loki_host>:3100 with your actual Loki server URL.

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🔄 Reload Alloy Configuration

After updating the config file (usually located at /etc/alloy/config.alloy), reload the service:

sudo systemctl reload alloy

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✅ Summary

🧩 Component	🔧 Action
Prometheus	Scrapes Alloy metrics from 127.0.0.1:12345
Loki	Receives logs from Alloy via syslog pipeline

Alloy now acts as a collector for both metrics and logs! 🚀