SIENTIAPDE-1084

Remove deprecated files and enhance documentation

- Deleted `coverage.sh`, `docker-compose.yaml`, `Dockerfile`, and simulator-related files to streamline the project structure.
- Updated `README.md` to provide a comprehensive overview of the OPC Ingestor, including features, architecture, installation, usage, and troubleshooting.
- Enhanced docstrings across various classes and methods in the `ingestor` module for better clarity and maintainability.
- Improved Prometheus metrics documentation in `metrics.py` to ensure proper monitoring and observability of the system.

ingestor/app.py

@@ -15,6 +15,29 @@ POD_ID = os.getenv("HOSTNAME", "localhost")
 
 
 async def main():
+    """
+    Main asynchronous function that orchestrates the OPC Ingestor application.
+
+    This function performs the following operations:
+    1. Starts the Prometheus metrics server for monitoring
+    2. Initializes the Ingestor instance
+    3. Prepares the ingestor (connects to services, acquires slot leases)
+    4. Runs the main processing loop until shutdown is requested
+    5. Handles graceful shutdown and cleanup
+
+    The main loop continuously:
+    - Processes OPC data from subscribed tags
+    - Manages slot leases and resource allocation
+    - Monitors OPC server connections
+    - Records metrics for monitoring and observability
+
+    Environment Variables:
+        HOSTNAME: Pod identifier for metrics labeling (default: "localhost")
+        HTTP_METRICS_PORT: Port for Prometheus metrics server (default: 9090)
+
+    Raises:
+        Exception: If ingestor preparation fails, the application will exit
+    """
     start_prometheus_server()
     ingestor = Ingestor()
     try:
@@ -62,11 +85,35 @@ async def main():
 
 
 def signal_handler(_signum, _frame):
+    """
+    Signal handler for graceful application shutdown.
+
+    This function handles system signals (SIGINT, SIGTERM, SIGHUP) by setting
+    the exit_signal flag, which triggers the main loop to complete its current
+    iteration and then shut down gracefully.
+
+    Args:
+        _signum: The signal number received
+        _frame: The current stack frame (unused)
+    """
     print(f"Received signal {_signum}. Setting exit_signal flag.")
     exit_signal.set()
 
 
 def start_prometheus_server():
+    """
+    Starts the Prometheus metrics HTTP server.
+
+    This function initializes a Prometheus metrics server on the configured port
+    to expose application metrics for monitoring and alerting. The server provides
+    metrics about application health, performance, and operational status.
+
+    Environment Variables:
+        HTTP_METRICS_PORT: Port number for the metrics server (default: 9090)
+
+    Raises:
+        Exception: If the server fails to start, the application will exit
+    """
     try:
         port = int(os.getenv("HTTP_METRICS_PORT", 9090))
         start_http_server(port)
@@ -78,7 +125,15 @@ def start_prometheus_server():
 
 
 def run_async_main():
-    """Run the async main function with proper event loop setup"""
+    """
+    Run the async main function with proper event loop setup.
+
+    This function sets up the asyncio event loop and runs the main async function.
+    It handles KeyboardInterrupt gracefully and ensures proper cleanup of the event loop.
+
+    The function is designed to work with both direct execution and containerized
+    environments, providing consistent behavior across different deployment scenarios.
+    """
     try:
         loop = asyncio.new_event_loop()
         asyncio.set_event_loop(loop)