Add Grafana Tempo distributed tracing with demo application

- Deploy Grafana Tempo in monolithic mode for distributed tracing
- Configure Tempo with OTLP receivers (gRPC:4317, HTTP:4318)
- Set up 10Gi filesystem storage with 7-day retention
- Integrate Tempo datasource in Grafana with traces-to-logs and traces-to-metrics correlation

- Update Grafana Alloy to collect and forward traces
- Add OTLP receiver configuration to alloy-values.yaml
- Configure batch processor for efficient trace forwarding to Tempo
- Patch Alloy service to expose OTLP ports 4317/4318

- Create demo tracing application (frontend, middleware, backend)
- Implement three-tier Python Flask application with OpenTelemetry instrumentation
- Auto-instrument with OpenTelemetry for Flask and requests libraries
- Push Docker images to private registry (registry.lan.buetow.org:30001)
- Deploy via Helm chart with Traefik ingress at tracing-demo.f3s.buetow.org

- Update Grafana configuration in prometheus/persistence-values.yaml
- Add Tempo to additionalDataSources for automatic provisioning

Files added:
- tempo/values.yaml: Tempo Helm chart configuration
- tempo/persistent-volumes.yaml: Storage configuration (10Gi PV/PVC)
- tempo/datasource-configmap.yaml: Grafana datasource with correlations
- tempo/Justfile: Installation automation
- tempo/README.md: Documentation

- tracing-demo/docker/frontend/: Python Flask frontend with OTel
- tracing-demo/docker/middleware/: Python Flask middleware with OTel
- tracing-demo/docker/backend/: Python Flask backend with OTel
- tracing-demo/helm-chart/: Kubernetes deployments, services, ingress
- tracing-demo/docker-image-Justfile: Docker build/push automation
- tracing-demo/Justfile: Helm deployment automation
- tracing-demo/README.md: Documentation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/f3s/tracing-demo/docker/frontend/Dockerfile b/f3s/tracing-demo/docker/frontend/Dockerfile
new file mode 100644
index 0000000..dd28e97
--- /dev/null
+++ b/f3s/tracing-demo/docker/frontend/Dockerfile
@@ -0,0 +1,16 @@
+FROM python:3.11-slim
+
+WORKDIR /app
+
+# Copy and install dependencies
+COPY requirements.txt .
+RUN pip install --no-cache-dir -r requirements.txt
+
+# Copy application code
+COPY app.py .
+
+# Expose port for Flask application
+EXPOSE 5000
+
+# Run the application
+CMD ["python", "app.py"]