Adjusted the python app example

Author: reggeenr

.gitignore

@@ -6,4 +6,5 @@ node_modules
 # draw.io temp files
 .$*.bkp
 .$*.dtmp
-venv
+venv
+__pycache__

metrics-examples/.ceignore

@@ -1,3 +1,5 @@
 node_modules/
 target/
-vendor/
+vendor/
+venv/
+__pycache__

metrics-examples/README.md

@@ -45,18 +45,6 @@ ibmcloud ce application create \
 ./run all
 ```
 
-## Language Comparison
-
-| Feature | Node.js | Go | Java | Python |
-|---------|---------|-----|------|--------|
-| **Framework** | Express | Gorilla Mux | Spring Boot | FastAPI |
-| **Metrics Library** | prom-client | prometheus/client_golang | Micrometer | prometheus-client |
-| **Startup Time** | ~1s | <1s | ~5-10s | ~2-3s |
-| **Memory Footprint** | ~150-200 MB | ~20-30 MB | ~200-250 MB | ~100-150 MB |
-| **Image Size** | ~150-200 MB | ~20-30 MB | ~200-250 MB | ~100-150 MB |
-| **Concurrency Model** | Event loop | Goroutines | Threads | Async/await |
-| **Best For** | Rapid development | Performance & efficiency | Enterprise apps | Modern APIs |
-
 ## Metrics
 
 All applications expose Prometheus metrics at `/metrics` (port 2112). All metric names are prefixed with a configurable value set via the `METRICS_NAME_PREFIX` environment variable (default: `mymetrics_`).
@@ -209,17 +197,3 @@ metrics-examples/
 ├── load-test.sh    # Load testing script
 └── README.md       # This file
 ```
-
-## Contributing
-
-When adding new features or metrics:
-
-1. Implement the feature in all four languages
-2. Use identical metric names across all implementations
-3. Maintain consistent API endpoints
-4. Update all language-specific README files
-5. Test with the load-test.sh script
-
-## License
-
-See individual language directories for specific dependencies and licenses.

metrics-examples/python/Dockerfile

@@ -1,24 +1,22 @@
-# Use Python slim image
-FROM python:3.12-slim
 
-WORKDIR /app
+# Download dependencies in builder stage
+FROM registry.access.redhat.com/ubi9/python-312 AS builder
 
 # Install dependencies
 COPY requirements.txt .
-RUN pip install --no-cache-dir -r requirements.txt
+RUN python -m pip install -r requirements.txt
 
-# Copy application code
-COPY . .
+# Build final stage
+FROM registry.access.redhat.com/ubi10/python-312-minimal
 
-# Set environment
-ENV PYTHONUNBUFFERED=1
+ENV PYTHONPATH=/opt/app-root/lib/${PYTHON_VERSION}/site-packages
 
-# Create non-root user
-RUN useradd -m -u 1001 appuser && chown -R appuser:appuser /app
-USER appuser
+COPY --chown=1001:0 --from=builder /opt/app-root/lib/python3.12/site-packages ${PYTHONPATH}
+COPY --chown=1001:0 app.py /opt/app-root/src/
+COPY --chown=1001:0 utils/ /opt/app-root/src/utils
+COPY --chown=1001:0 log_conf.yaml /opt/app-root/src/
 
-# Expose ports
-EXPOSE 8080 2112
+USER 1001:0
+WORKDIR /opt/app-root/src
 
-# Run the application with uvicorn
-CMD ["uvicorn", "app:app", "--host", "0.0.0.0", "--port", "8080"]
+CMD python app.py

metrics-examples/python/README.md

@@ -2,6 +2,29 @@
 
 This application helps debug connectivity issues for IBM Cloud Services and provides comprehensive monitoring through Prometheus metrics. It includes outbound HTTP call simulation, database connectivity testing, and compute-intensive workload simulation.
 
+## Architecture
+
+```
+┌─────────────────────────────────────┐
+│         Container                   │
+│                                     │
+│  ┌────────────────────────────┐     │
+│  │  Main Application Server   │     │
+│  │  Port: 8080                │     │
+│  │  - /                       │     │
+│  │  - /test-db                │     │
+│  │  - /outbound/*             │     │
+│  └────────────────────────────┘     │
+│                                     │
+│  ┌────────────────────────────┐     │
+│  │  Metrics Server (Thread)   │     │
+│  │  Port: 2112                │     │
+│  │  - /metrics                │     │
+│  └────────────────────────────┘     │
+│                                     │
+└─────────────────────────────────────┘
+```
+
 ## Features
 
 - **Outbound HTTP Calls**: Configurable endpoints that simulate delays and error responses to httpbin.org-compatible backends
@@ -46,32 +69,6 @@ ibmcloud ce application update \
   --env HTTPBIN_BASE_URL=https://custom-backend.example.com
 ```
 
-### Run Locally
-
-Pull and run with Docker:
-```bash
-docker pull icr.io/codeengine/metrics-example-app-python
-docker run -p 8080:8080 -p 2112:2112 icr.io/codeengine/metrics-example-app-python
-```
-
-Or run from source:
-```bash
-pip install -r requirements.txt
-python app.py
-```
-
-Or with uvicorn directly:
-```bash
-pip install -r requirements.txt
-uvicorn app:app --host 0.0.0.0 --port 8080
-```
-
-The application exposes:
-- Main application: `http://localhost:8080`
-- Metrics endpoint: `http://localhost:8080/metrics`
-- Interactive API docs: `http://localhost:8080/docs`
-- Alternative API docs: `http://localhost:8080/redoc`
-
 ## Configuration
 
 ### Environment Variables
@@ -93,15 +90,14 @@ For database connectivity, create a Code Engine service binding between your pro
 - `GET /outbound/get` - Simple outbound GET request
 - `POST /outbound/post` - Outbound POST request
 - `GET /outbound/status/{code}` - Request specific HTTP status code
-- `GET /metrics` - Prometheus metrics endpoint
 - `GET /docs` - Interactive API documentation (Swagger UI)
 - `GET /redoc` - Alternative API documentation (ReDoc)
 
 All outbound endpoints include simulated compute-intensive data processing (0-3s duration, 40-80% CPU intensity).
 
 ## Metrics
 
-The application exposes Prometheus metrics at `/metrics`. All metric names are prefixed with a configurable value set via the `METRICS_NAME_PREFIX` environment variable (default: `mymetrics_`).
+The application exposes Prometheus metrics on a **separate metrics server** at `http://localhost:2112/metrics`. This separation provides better security and performance isolation. All metric names are prefixed with a configurable value set via the `METRICS_NAME_PREFIX` environment variable (default: `mymetrics_`).
 
 **Request Metrics**
 - `mymetrics_requests_total`: Total requests by method and path
@@ -123,44 +119,65 @@ The application exposes Prometheus metrics at `/metrics`. All metric names are p
 
 ## Development
 
+### Project Structure
+
+```
+python/
+├── app.py                  # FastAPI application entry point
+├── requirements.txt        # Python dependencies
+├── Dockerfile              # Multi-stage Docker build
+├── README.md               # This file
+└── utils/
+    ├── __init__.py         # Package initialization
+    ├── metrics.py          # Prometheus metrics definitions
+    ├── db.py               # PostgreSQL connection handling
+    └── compute.py          # Compute simulation utilities
+```
+
 ### Prerequisites
 
 - Python 3.12 or later
 - pip or poetry for package management
-- Docker (for containerized builds)
+- Docker or Podman (for containerized builds)
 
-### Building
+### Run Locally
+
+Pull and run with Docker:
+```bash
+docker pull icr.io/codeengine/metrics-example-app-python
+docker run -p 8080:8080 -p 2112:2112 icr.io/codeengine/metrics-example-app-python
+```
 
+Or run from source:
 ```bash
-# Install dependencies
-pip install -r requirements.txt
+python3 -m venv venv
+source venv/bin/activate
 
-# Run the application
+python -m pip install -r requirements.txt
 python app.py
 
-# Or with uvicorn for development (with auto-reload)
-uvicorn app:app --reload --host 0.0.0.0 --port 8080
 
-# Build Docker image
-docker build -t metrics-example-app-python .
+# Test main application (in another terminal)
+curl http://localhost:8080/
+
+# Test metrics endpoint
+curl http://localhost:2112/metrics
 
-# Run tests (if you add them)
-pytest
+# Test graceful shutdown
+# Send SIGTERM or press Ctrl+C
 ```
 
-### Project Structure
+The application exposes:
+- Main application: `http://localhost:8080`
+- Metrics endpoint: `http://localhost:2112/metrics`
+- Interactive API docs: `http://localhost:8080/docs`
+- Alternative API docs: `http://localhost:8080/redoc`
 
-```
-python/
-├── app.py                  # FastAPI application entry point
-├── requirements.txt        # Python dependencies
-├── Dockerfile              # Multi-stage Docker build
-├── README.md               # This file
-└── utils/
-    ├── __init__.py         # Package initialization
-    ├── metrics.py          # Prometheus metrics definitions
-    ├── db.py               # PostgreSQL connection handling
-    └── compute.py          # Compute simulation utilities
+### Building
+
+```bash
+# Build Docker image
+podman build -t metrics-example-app-python .
 ```
 
 ## Performance Characteristics
@@ -202,20 +219,33 @@ pip install --upgrade asyncpg
 
 ### Performance Issues
 
-For better performance in production:
+For better performance in production, you need to run both the main application and metrics server separately:
 
 ```bash
-# Use gunicorn with uvicorn workers
+# Install gunicorn
 pip install gunicorn
+
+# Option 1: Run both servers using the default app.py (recommended for simplicity)
+python3 app.py
+
+# Option 2: For production with multiple workers, run servers separately:
+
+# Terminal 1: Run main application with gunicorn (multiple workers)
 gunicorn app:app -w 4 -k uvicorn.workers.UvicornWorker --bind 0.0.0.0:8080
+
+# Terminal 2: Run metrics server separately (single worker is sufficient)
+gunicorn app:metrics_app -w 1 -k uvicorn.workers.UvicornWorker --bind 0.0.0.0:2112
+
+# Option 3: Use a process manager like supervisord or systemd to manage both processes
 ```
 
+**Note**: When using gunicorn with multiple workers for the main app, the metrics server should run as a separate process. The default `python3 app.py` approach handles both servers automatically in a single process, which is simpler for most use cases.
+
 ## FastAPI Features
 
 This implementation uses FastAPI, which provides:
 
 - **Automatic API Documentation**: Visit `/docs` for Swagger UI or `/redoc` for ReDoc
-- **Type Validation**: Automatic request/response validation using Pydantic
 - **Async Support**: Native async/await for non-blocking I/O
 - **High Performance**: One of the fastest Python frameworks available
 - **Standards-based**: Based on OpenAPI and JSON Schema