Lab01 Submission - Bulat Gazizov

app_python/.gitignore

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+# Python
+__pycache__/
+*.py[cod]
+.venv/
+*.log
+
+# IDE
+.vscode/
+.idea/
+
+# OS
+.DS_Store

app_python/README.md

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+# Overview
+
+Lightweight web application built using __FastAPI__. It provides essential service and system information, along with a health check endpoint to monitor application status. The application shares various details about the server environment, including runtime status and configuration.
+
+## Prerequisites
+
+Before you begin, ensure you have the following prerequisites:
+
+Python Version: Python 3.11 or higher
+Dependencies: The application depends on the FastAPI framework and other packages specified in the requirements.txt file.
+
+## Installation
+
+```bash
+python -m venv venv
+source venv/bin/activate
+pip install -r requirements.txt
+```
+
+## Running the Application
+
+```bash python app.py
+# Or with custom config
+PORT=8080 python app.py
+```
+
+## API Endpoints
+
+| Method | Endpoint   | Description                             |
+|--------|------------|-----------------------------------------|
+| GET    | /          | Service and system information.         |
+| GET    | /health    | Health check for the application.       |
+
+### `/` - Service and System Information
+
+This endpoint returns information about the service, system details, and configuration.
+
+### `/health` - Health Check
+
+This endpoint returns the health status of the application along with the current timestamp.
+
+## Configuration
+
+| Environment Variable | Description                             | Default Value |
+|----------------------|-----------------------------------------|---------------|
+| `HOST`               | The host address for the application.   | `0.0.0.0`     |
+| `PORT`               | The port the application listens on.    | `5000`        |
+| `DEBUG`              | Enables debug mode if set to `true`.    | `false`       |

app_python/app.py

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+from typing import Union
+
+from fastapi import FastAPI, Request
+from fastapi.responses import JSONResponse
+import os
+import platform
+import socket
+from datetime import datetime, timezone
+import logging
+
+HOST = os.getenv('HOST', '0.0.0.0')
+PORT = int(os.getenv('PORT', 5000))
+DEBUG = os.getenv('DEBUG', 'False').lower() == 'true'
+
+logging.basicConfig(
+    level=logging.INFO if not DEBUG else logging.DEBUG,
+    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s'
+)
+logger = logging.getLogger(__name__)
+
+
+app = FastAPI()
+start_time = datetime.now()
+
+
+@app.get("/")
+def read_root(request: Request):
+    logger.debug(f'Request: {request.method} {request.url}')
+    hostname = socket.gethostname()
+    platform_name = platform.system()
+    platform_ver = platform.release()
+    architecture = platform.machine()
+    cpu_cores = os.cpu_count()
+    python_version = platform.python_version()
+    url_list = [{"path": route.path, "description": route.name,
+                 "methods": route.methods} for route in app.routes]
+    return {
+        "service": {
+            "name": "devops-info-service",
+            "version": "1.0.0",
+            "description": "DevOps course info service",
+            "framework": "FastAPI"
+        },
+        "system": {
+            "hostname": hostname,
+            "platform": platform_name,
+            "platform_version": platform_ver,
+            "architecture": architecture,
+            "cpu_count": cpu_cores,
+            "python_version": python_version
+        },
+        "runtime": {
+            "uptime_seconds": get_uptime()['seconds'],
+            "uptime_human": get_uptime()['human'],
+            "current_time": datetime.now(timezone.utc).isoformat(),
+            "timezone": "UTC"
+        },
+        "request": {
+            "client_ip": request.client.host,
+            "user_agent": request.headers.get('user-agent'),
+            "method": request.method,
+            "path": request.url.path
+        },
+        "endpoints": url_list
+    }
+
+
+@app.get("/health")
+def health(request: Request):
+    logger.debug(f'Request: {request.method} {request.url}')
+    return {
+        'status': 'healthy',
+        'timestamp': datetime.now(timezone.utc).isoformat(),
+        'uptime_seconds': get_uptime()['seconds']
+    }
+
+
+def get_uptime():
+    delta = datetime.now() - start_time
+    seconds = int(delta.total_seconds())
+    hours = seconds // 3600
+    minutes = (seconds % 3600) // 60
+    return {
+        'seconds': seconds,
+        'human': f"{hours} hours, {minutes} minutes"
+    }
+
+
+@app.exception_handler(404)
+async def not_found(request, exc):
+    return JSONResponse(
+        status_code=404,
+        content={
+            'error': 'Not Found',
+            'message': 'Endpoint does not exist'
+        }
+    )
+
+# Custom error handler for 500 Internal Server Error
+
+
+@app.exception_handler(500)
+async def internal_error(request, exc):
+    return JSONResponse(
+        status_code=500,
+        content={
+            'error': 'Internal Server Error',
+            'message': 'An unexpected error occurred'
+        }
+    )
+
+if __name__ == "__main__":
+    import uvicorn
+    logger.info('Application starting...')
+    uvicorn.run(app, host=HOST, port=PORT,
+                log_level='debug' if DEBUG else 'info')

app_python/docs/LAB01.md

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+# Lab 01
+
+## Framework Selection
+
+Choice: FastAPI
+
+Why? FastAPI is designed specifically for building high-performance APIs with Python. It provides automatic data validation and generates interactive documentation (Swagger UI) out of the box.
+
+## Best Practices Applied
+
+### Environment configation
+
+The application avoids hardcoding sensitive or environment-specific values. It uses os.getenv to allow configuration via container environments or .env files.
+
+```python
+HOST = os.getenv('HOST', '0.0.0.0')
+PORT = int(os.getenv('PORT', 5000))
+DEBUG = os.getenv('DEBUG', 'False').lower() == 'true'
+```
+
+### Logging
+
+Instead of using print() statements, the service implements the standard logging library with configurable levels.
+
+```python
+logging.basicConfig(
+    level=logging.INFO if not DEBUG else logging.DEBUG,
+    format='%(asctime)s - %(name)s - %(levelname)s - %(message)s'
+)
+```
+
+## API Documentation
+
+### Endpoint: Root Info
+
+Path: /
+
+Method: GET
+
+Response Example:
+
+```json
+{
+  "service": { "name": "devops-info-service", "version": "1.0.0" },
+  "system": { "hostname": "local-machine", "platform": "Linux" },
+  "runtime": { "uptime_seconds": 120 }
+}
+```
+
+### Endpoint: Health Check
+
+Path: /health
+
+Method: GET
+
+Response Example:
+
+```json
+{
+  "status": "healthy",
+  "timestamp": "2026-01-27T18:30:00Z",
+  "uptime_seconds": 120
+}
+```
+
+### Testing Commands
+
+To test the service via CLI, use curl:
+
+```bash
+# Test Root Info
+curl http://localhost:5000/
+
+# Test Health Check
+curl http://localhost:5000/health
+```
+
+### Testing Evidence
+
+![application](screenshots/startup.png?raw=true "Running application")
+
+![health endpoint](screenshots/health.png?raw=true "Health endpoint")
+
+![root endpoint](screenshots/root.png?raw=true "Root info")
+
+### Challenges & Solutions
+
+I forgot how to launch a fastapi application via uicorn without a direct command in the terminal.
+
+Solution:
+
+```python
+if __name__ == "__main__":
+    import uvicorn
+    uvicorn.run(app, host=HOST, port=PORT,
+                log_level='debug' if DEBUG else 'info')
+```

app_python/requirements.txt

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+annotated-doc==0.0.4
+annotated-types==0.7.0
+anyio==4.12.1
+certifi==2026.1.4
+click==8.3.1
+dnspython==2.8.0
+email-validator==2.3.0
+fastapi==0.128.0
+fastapi-cli==0.0.20
+fastapi-cloud-cli==0.11.0
+fastar==0.8.0
+h11==0.16.0
+httpcore==1.0.9
+httptools==0.7.1
+httpx==0.28.1
+idna==3.11
+Jinja2==3.1.6
+markdown-it-py==4.0.0
+MarkupSafe==3.0.3
+mdurl==0.1.2
+pydantic==2.12.5
+pydantic-extra-types==2.11.0
+pydantic-settings==2.12.0
+pydantic_core==2.41.5
+Pygments==2.19.2
+python-dotenv==1.2.1
+python-multipart==0.0.22
+PyYAML==6.0.3
+rich==14.3.1
+rich-toolkit==0.17.1
+rignore==0.7.6
+sentry-sdk==2.50.0
+shellingham==1.5.4
+starlette==0.50.0
+typer==0.21.1
+typing-inspection==0.4.2
+typing_extensions==4.15.0
+urllib3==2.6.3
+uvicorn==0.40.0
+uvloop==0.22.1
+watchfiles==1.1.1
+websockets==16.0