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Server_Monitorizare/explanations and old code/CODE_COMPARISON.md
Developer 376240fb06 Add configuration, utilities, and update server with enhanced monitoring features
- Add config.py for environment configuration management
- Add utils.py with utility functions
- Add .env.example for environment variable reference
- Add routes_example.py as route reference
- Add login.html template for authentication
- Update server.py with enhancements
- Update all dashboard and log templates
- Move documentation to 'explanations and old code' directory
- Update database schema
2025-12-18 09:11:11 +02:00

597 lines
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# Code Refactoring Examples - Side by Side Comparison
## 1. Authentication & Decorators
### ❌ BEFORE (No Authentication)
```python
@app.route('/logs', methods=['POST'])
@app.route('/log', methods=['POST'])
def log_event():
try:
# Get the JSON payload
data = request.json
if not data:
return {"error": "Invalid or missing JSON payload"}, 400
# Extract fields - NO VALIDATION
hostname = data.get('hostname')
device_ip = data.get('device_ip')
# ... anyone can access this!
```
### ✅ AFTER (With Authentication & Validation)
```python
@logs_bp.route('', methods=['POST'])
@require_auth # NEW: Requires API key
@log_request # NEW: Logs request
@validate_required_fields(['hostname', 'device_ip']) # NEW: Validates fields
def log_event():
try:
data = request.get_json()
# Validate and sanitize
hostname = sanitize_hostname(data['hostname']) # NEW: Format validation
if not validate_ip_address(data['device_ip']): # NEW: IP validation
raise APIError("Invalid IP address", 400)
# Now protected and validated!
```
**Benefits:**
- ✅ Only authorized clients can submit logs
- ✅ Input is validated before processing
- ✅ All requests are logged for audit trail
- ✅ Clear error messages
---
## 2. Error Handling
### ❌ BEFORE (Inconsistent Error Responses)
```python
def log_event():
try:
if not data:
return {"error": "Invalid or missing JSON payload"}, 400 # Format 1
if not hostname:
return {"error": "Missing required fields"}, 400 # Format 2
# ...
except sqlite3.Error as e:
return {"error": f"Database connection failed: {e}"}, 500 # Format 3
except Exception as e:
return {"error": "An unexpected error occurred"}, 500 # Format 4
```
### ✅ AFTER (Standardized Error Responses)
```python
def log_event():
try:
if not data:
raise APIError("Invalid or missing JSON payload", 400) # Unified format
if not hostname:
raise APIError("Missing required fields", 400) # Same format
# ...
except APIError as e:
logger.error(f"API Error: {e.message}")
return error_response(e.message, e.status_code) # Consistent!
except sqlite3.Error as e:
logger.error(f"Database error: {e}", exc_info=True)
raise APIError("Database connection failed", 500) # Always same format
except Exception as e:
logger.exception("Unexpected error")
raise APIError("Internal server error", 500)
@app.errorhandler(APIError)
def handle_api_error(e):
return error_response(e.message, e.status_code, e.details)
```
**Benefits:**
- ✅ All errors follow same format
- ✅ Client can parse responses consistently
- ✅ Errors are logged with full context
- ✅ Easy to add monitoring/alerting
---
## 3. Logging System
### ❌ BEFORE (Print Statements)
```python
def log_event():
try:
#print(f"Connecting to database at: {DATABASE}")
# Get the JSON payload
data = request.json
if not data:
return {"error": "Invalid or missing JSON payload"}, 400
#print(f"Received request data: {data}")
# ... code ...
print("Log saved successfully") # Lost in terminal output
return {"message": "Log saved successfully"}, 201
except sqlite3.Error as e:
print(f"Database error: {e}") # Not structured, hard to parse
return {"error": f"Database connection failed: {e}"}, 500
except Exception as e:
print(f"Unexpected error: {e}") # No stack trace
return {"error": "An unexpected error occurred"}, 500
```
### ✅ AFTER (Proper Logging)
```python
logger = logging.getLogger(__name__)
def log_event():
try:
logger.debug(f"Log event request from {request.remote_addr}")
data = request.get_json()
if not data:
logger.warning("Empty JSON payload received")
raise APIError("Invalid payload", 400)
logger.debug(f"Received request data: {data}")
# ... code ...
logger.info(f"Log saved for {hostname} from {device_ip}") # Structured!
return success_response({"log_id": cursor.lastrowid}, 201)
except sqlite3.Error as e:
logger.error(f"Database error: {e}", exc_info=True) # Full traceback
raise APIError("Database connection failed", 500)
except Exception as e:
logger.exception("Unexpected error in log_event") # Context included
raise APIError("Internal server error", 500)
```
**Log Output Example:**
```
2025-12-17 10:30:45 - app - DEBUG - Log event request from 192.168.1.100
2025-12-17 10:30:45 - app - DEBUG - Received request data: {...}
2025-12-17 10:30:46 - app - INFO - Log saved for rpi-01 from 192.168.1.101
2025-12-17 10:30:50 - app - ERROR - Database error: unable to connect
Traceback (most recent call last):
File "server.py", line 42, in log_event
cursor.execute(...)
...
```
**Benefits:**
- ✅ Logs go to file with rotation
- ✅ Different severity levels (DEBUG, INFO, WARNING, ERROR)
- ✅ Full stack traces for debugging
- ✅ Timestamps included automatically
- ✅ Can be parsed by log aggregation tools (ELK, Splunk, etc.)
- ✅ Production support becomes possible
---
## 4. Configuration Management
### ❌ BEFORE (Hardcoded Values)
```python
DATABASE = 'data/database.db' # Hardcoded path
PORT = 80 # Hardcoded port
REQUEST_TIMEOUT = 30 # Hardcoded timeout
# Throughout the code:
response = requests.post(url, json=payload, timeout=30) # Magic number
with sqlite3.connect(DATABASE) as conn: # Uses global
app.run(host='0.0.0.0', port=80) # Hardcoded
# Problems:
# - Different values needed for dev/test/prod
# - Secret values exposed in code
# - Can't change without code changes
```
### ✅ AFTER (Environment-Based Configuration)
```python
# config.py
import os
from dotenv import load_dotenv
load_dotenv()
class Config:
DATABASE_PATH = os.getenv('DATABASE_PATH', 'data/database.db')
PORT = int(os.getenv('PORT', 80))
REQUEST_TIMEOUT = int(os.getenv('REQUEST_TIMEOUT', 30))
API_KEY = os.getenv('API_KEY', 'change-me') # From .env
DEBUG = os.getenv('DEBUG', 'False').lower() == 'true'
LOG_LEVEL = os.getenv('LOG_LEVEL', 'INFO')
class ProductionConfig(Config):
DEBUG = False
LOG_LEVEL = 'INFO'
# server.py
from config import get_config
config = get_config()
response = requests.post(url, json=payload, timeout=config.REQUEST_TIMEOUT)
with sqlite3.connect(config.DATABASE_PATH) as conn:
# ...
app.run(host='0.0.0.0', port=config.PORT)
# .env (local)
DATABASE_PATH=/var/lib/server_mon/database.db
PORT=8000
DEBUG=True
API_KEY=my-secure-key
# Benefits:
# - Same code, different configs
# - Secrets not in version control
# - Easy deployment to prod
```
**Benefits:**
- ✅ Environment-specific configuration
- ✅ Secrets in .env (not committed to git)
- ✅ Easy deployment
- ✅ No code changes needed per environment
- ✅ Supports dev/test/prod differences
---
## 5. Input Validation
### ❌ BEFORE (Minimal Validation)
```python
def log_event():
# Get the JSON payload
data = request.json
if not data:
return {"error": "Invalid or missing JSON payload"}, 400
# Extract fields from the JSON payload
hostname = data.get('hostname')
device_ip = data.get('device_ip')
nume_masa = data.get('nume_masa')
log_message = data.get('log_message')
timestamp = datetime.now().strftime('%Y-%m-%d %H:%M:%S')
# Validate required fields
if not hostname or not device_ip or not nume_masa or not log_message:
print("Validation failed: Missing required fields")
return {"error": "Missing required fields"}, 400
# NO FORMAT VALIDATION
# - hostname could be very long
# - device_ip could be invalid format
# - log_message could contain injection payloads
# - No type checking
```
### ✅ AFTER (Comprehensive Validation)
```python
from marshmallow import Schema, fields, validate, ValidationError
class LogSchema(Schema):
"""Define expected schema and validation rules"""
hostname = fields.Str(
required=True,
validate=[
validate.Length(min=1, max=255),
validate.Regexp(r'^[a-zA-Z0-9_-]+$', error="Invalid characters")
]
)
device_ip = fields.IP(required=True) # Validates IP format
nume_masa = fields.Str(
required=True,
validate=validate.Length(min=1, max=255)
)
log_message = fields.Str(
required=True,
validate=validate.Length(min=1, max=1000)
)
schema = LogSchema()
def log_event():
try:
data = schema.load(request.json) # Auto-validates all fields
hostname = data['hostname'] # Already validated
device_ip = data['device_ip'] # Already validated
# Data is guaranteed to be valid format
except ValidationError as err:
logger.warning(f"Validation failed: {err.messages}")
return error_response("Validation failed", 400, err.messages)
```
**Validation Errors (Clear Feedback):**
```
{
"errors": {
"hostname": ["Length must be between 1 and 255"],
"device_ip": ["Not a valid IP address"],
"log_message": ["Length must be between 1 and 1000"]
}
}
```
**Benefits:**
- ✅ Clear validation rules (declarative)
- ✅ Reusable schemas
- ✅ Type checking
- ✅ Length limits
- ✅ Format validation (IP, email, etc.)
- ✅ Custom validators
- ✅ Detailed error messages for client
---
## 6. Database Queries
### ❌ BEFORE (No Pagination)
```python
@app.route('/dashboard', methods=['GET'])
def dashboard():
with sqlite3.connect(DATABASE) as conn:
cursor = conn.cursor()
# Fetch the last 60 logs - loads ALL into memory
cursor.execute('''
SELECT hostname, device_ip, nume_masa, timestamp, event_description
FROM logs
WHERE hostname != 'SERVER'
ORDER BY timestamp DESC
LIMIT 60
''')
logs = cursor.fetchall()
return render_template('dashboard.html', logs=logs)
# Problem: As table grows to 100k rows
# - Still fetches into memory
# - Page takes longer to load
# - Memory usage grows
```
### ✅ AFTER (With Pagination)
```python
@logs_bp.route('/dashboard', methods=['GET'])
def dashboard():
page = request.args.get('page', 1, type=int)
per_page = min(
request.args.get('per_page', config.DEFAULT_PAGE_SIZE, type=int),
config.MAX_PAGE_SIZE
)
conn = get_db_connection(config.DATABASE_PATH)
try:
cursor = conn.cursor()
# Get total count
cursor.execute('SELECT COUNT(*) FROM logs WHERE hostname != "SERVER"')
total = cursor.fetchone()[0]
# Get only requested page
offset = (page - 1) * per_page
cursor.execute('''
SELECT hostname, device_ip, nume_masa, timestamp, event_description
FROM logs
WHERE hostname != 'SERVER'
ORDER BY timestamp DESC
LIMIT ? OFFSET ?
''', (per_page, offset))
logs = cursor.fetchall()
total_pages = (total + per_page - 1) // per_page
return render_template(
'dashboard.html',
logs=logs,
page=page,
total_pages=total_pages,
total=total
)
finally:
conn.close()
# Usage: /dashboard?page=1&per_page=20
# Benefits:
# - Only fetches 20 rows
# - Memory usage constant regardless of table size
# - Can navigate pages easily
```
**Benefits:**
- ✅ Constant memory usage
- ✅ Faster page loads
- ✅ Can handle large datasets
- ✅ Better UX with page navigation
---
## 7. Threading & Concurrency
### ❌ BEFORE (Unbounded Threads)
```python
@app.route('/execute_command_bulk', methods=['POST'])
def execute_command_bulk():
try:
data = request.json
device_ips = data.get('device_ips', [])
command = data.get('command')
results = {}
threads = []
def execute_on_device(ip):
results[ip] = execute_command_on_device(ip, command)
# Execute commands in parallel
for ip in device_ips: # No limit!
thread = threading.Thread(target=execute_on_device, args=(ip,))
threads.append(thread)
thread.start() # Creates a thread for EACH IP
# Wait for all threads to complete
for thread in threads:
thread.join()
# Problem: If user sends 1000 devices, creates 1000 threads!
# - Exhausts system memory
# - System becomes unresponsive
# - No control over resource usage
```
### ✅ AFTER (ThreadPoolExecutor with Limits)
```python
from concurrent.futures import ThreadPoolExecutor, as_completed
@app.route('/execute_command_bulk', methods=['POST'])
def execute_command_bulk():
try:
data = request.json
device_ips = data.get('device_ips', [])
command = data.get('command')
# Limit threads
max_workers = min(
config.BULK_OPERATION_MAX_THREADS, # e.g., 10
len(device_ips)
)
results = {}
# Use ThreadPoolExecutor with bounded pool
with ThreadPoolExecutor(max_workers=max_workers) as executor:
# Submit all jobs
future_to_ip = {
executor.submit(execute_command_on_device, ip, command): ip
for ip in device_ips
}
# Process results as they complete
for future in as_completed(future_to_ip):
ip = future_to_ip[future]
try:
results[ip] = future.result()
except Exception as e:
logger.error(f"Error executing command on {ip}: {e}")
results[ip] = {"success": False, "error": str(e)}
return jsonify({"results": results}), 200
# Usage: Same API, but:
# - Max 10 threads running at once
# - Can handle 1000 devices gracefully
# - Memory usage is bounded
# - System stays responsive
```
**Benefits:**
- ✅ Bounded thread pool (max 10)
- ✅ No resource exhaustion
- ✅ Graceful handling of large requests
- ✅ Can process results as they complete
---
## 8. Response Formatting
### ❌ BEFORE (Inconsistent Responses)
```python
# Different response formats throughout
return {"message": "Log saved successfully"}, 201
return {"error": "Invalid or missing JSON payload"}, 400
return {"success": True, "status": result_data.get('status')}, 200
return {"error": error_msg}, 400
return jsonify({"results": results}), 200
# Client has to handle multiple formats
# Hard to parse responses consistently
# Hard to add metadata (timestamps, etc.)
```
### ✅ AFTER (Standardized Responses)
```python
# utils.py
def error_response(message, status_code=400, details=None):
response = {
'success': False,
'error': message,
'timestamp': datetime.now().isoformat()
}
if details:
response['details'] = details
return jsonify(response), status_code
def success_response(data=None, message="Success", status_code=200):
response = {
'success': True,
'message': message,
'timestamp': datetime.now().isoformat()
}
if data:
response['data'] = data
return jsonify(response), status_code
# Usage in routes
return success_response({"log_id": 123}, "Log saved successfully", 201)
return error_response("Invalid payload", 400, {"fields": ["hostname"]})
return success_response(results, message="Command executed")
# Consistent responses:
{
"success": true,
"message": "Log saved successfully",
"timestamp": "2025-12-17T10:30:46.123456",
"data": {
"log_id": 123
}
}
{
"success": false,
"error": "Invalid payload",
"timestamp": "2025-12-17T10:30:46.123456",
"details": {
"fields": ["hostname"]
}
}
```
**Benefits:**
- ✅ All responses have same format
- ✅ Client code is simpler
- ✅ Easier to add logging/monitoring
- ✅ Includes timestamp for debugging
- ✅ Structured error details
---
## Summary: Key Improvements at a Glance
| Aspect | Before | After |
|--------|--------|-------|
| **Security** | No auth | API key auth |
| **Logging** | print() | Proper logging with levels |
| **Errors** | Inconsistent formats | Standardized responses |
| **Validation** | Basic checks | Comprehensive validation |
| **Config** | Hardcoded values | Environment-based |
| **Database** | No pagination | Paginated queries |
| **Threading** | Unbounded | Bounded pool (max 10) |
| **Code Structure** | 462 lines in 1 file | Modular with blueprints |
| **Testing** | No tests | pytest ready |
| **Observability** | None | Health checks, stats, logs |
---
**Created**: December 17, 2025