Grafana + Promtail + .NET Logging Demo

This is a demo project that shows how to send logs from a custom .NET Core application to Grafana using Promtail and Loki. All components are containerized using Docker Compose.

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📦 Project Structure

grafana-dotnet-logging/
├── dotnet-app/
│   ├── Program.cs              # Writes logs to app.log
│   ├── LoggingDemo.csproj      # .NET 8 project
│   ├── Dockerfile              # Containerizes the app
│   └── logs/                   # Output log file directory (bind-mounted)
├── promtail-config.yaml        # Promtail config for scraping app.log
├── docker-compose.yml          # Defines Loki, Grafana, Promtail services
└── README.md

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🚀 How to Run

# Build the .NET logging app
cd dotnet-app
docker build -t dotnet-log .

# Run the logging app (this writes logs into logs/app.log)
docker run --rm -v $(pwd)/logs:/app/logs dotnet-log

# Start Grafana, Loki and Promtail
cd ..
docker-compose up --build

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🔎 View Logs in Grafana

1. Access Grafana: http://localhost:3000
   • Username: admin, Password: admin
2. Add Loki as a data source if not added automatically:
   • Data Sources → Add → Loki → URL: http://loki:3100
3. Go to Explore
4. Use query:

   {job="dotnet-app"}
   

You should see the logs generated by the .NET app.

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📚 Related Tools

Tool	Purpose
Grafana	Visualization dashboards
Loki	Log storage (time-series)
Promtail	Log shipper to Loki
.NET	Custom log-producing app

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