Send deduplicated Kubernetes(EKS/GKE/AKS) error logs from Grafana Loki to Slack

Last edited 58 days ago

✨ Summary

Efficiently monitor Kubernetes environments by sending only unique error logs from Grafana Loki to Slack. Reduces alert fatigue while keeping your team informed about critical log events.

🧑‍💻 Who’s it for

  • DevOps or SRE engineers running EKS/GKE/AKS
  • Anyone using Grafana Loki and Promtail for centralized logging
  • Teams that want Slack alerts but hate alert spam

🔍 What it does

This n8n workflow queries your Loki logs every 5 minutes, filters only the critical ones (error, timeout, exception, etc.), removes duplicate alerts within the batch, and sends clean alerts to a Slack channel with full metadata (pod, namespace, node, container, log, timestamp).

🧠 How it works

🕒 Schedule Trigger

Every 5 minutes (customizable)

🌐 Loki HTTP Query

Pulls logs from the last 10 minutes
Keyword match: error, failed, oom, etc.

🧹 Log Parsing

Extracts log fields (pod, container, etc.)
Skips empty/malformed results

🧠 Deduplication

Removes repeated error messages (within query window)

📤 Slack Notification

Sends nicely formatted message to Slack

⚙️ Requirements

Tool Notes

Loki- Exposed internally or externally
Slack App- With chat:write OAuth
n8n- Cloud or self-hosted

🔧 How to Set It Up

Import the JSON file into n8n

Update:

  • Loki API URL (e.g., http://loki-gateway.monitoring.svc.cluster.local)
  • Slack Bearer Token (via credentials)
  • Target Slack channel (e.g., #k8s-alerts)
  • (Optional) Change keywords in the query regex
  • Activate the workflow
  • Ensure n8n pod/container is having access to your kubernetes cluster/pods/namespaces

🛠 How to Customize

  • Want more or fewer keywords? Adjust the regex in the Query Loki for Error Logs node.
  • Need to increase deduplication logic? Enhance the Remove Duplicate Alerts node.
  • Want 5-log summaries every 5 min? Fork this and add a Batch + Slack group sender.

Grafana Loki logs to Slack Output

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