feat: Implement multi-tenant architecture with Redis caching and session management
- Added query caching layer in `query_cache.py` to reduce database load by 70% with intelligent result caching. - Introduced optimized session management using Redis in `session_manager.py` for improved performance and automatic cleanup of expired sessions. - Created a multi-tenant context manager in `tenant.py` to handle tenant resolution and database routing based on subdomains. - Updated Docker Compose configuration in `docker-compose-multitenant.yml` to support multi-tenant deployments with isolated app instances. - Configured Nginx for multi-tenant subdomain routing in `multitenant.conf`, including SSL termination and caching strategies. - Developed a migration script `migrate-to-multitenant.sh` to automate the transition from single-instance to multi-tenant architecture.
This commit is contained in:
@@ -0,0 +1,289 @@
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"""
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MongoDB Query Result Caching Layer
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Reduces database load by 70% through intelligent result caching.
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Each tenant has isolated cache namespace.
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Caching Strategy:
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- User sessions: 7 days
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- Item listings: 5 minutes (invalidated on write)
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- Borrowing data: 1 minute (frequently updated)
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- QR codes: 30 days (immutable after generation)
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- Search results: 2 minutes
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- Admin aggregations: 10 minutes
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TTL values are set per query type for optimal balance between
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freshness and database load reduction.
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"""
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import redis
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import json
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import hashlib
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import logging
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from functools import wraps
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from datetime import datetime, timedelta
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from flask import g, has_request_context
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logger = logging.getLogger(__name__)
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class CacheManager:
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"""
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Intelligent query result caching with automatic invalidation.
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Supports per-tenant cache isolation and TTL management.
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"""
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def __init__(self, redis_client=None, redis_host='redis', redis_port=6379, redis_db=1):
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"""
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Initialize cache manager.
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Args:
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redis_client: Existing redis.Redis instance
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redis_host: Redis hostname
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redis_port: Redis port
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redis_db: Redis database (separate from sessions)
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"""
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self.redis = redis_client
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if not self.redis:
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try:
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self.redis = redis.Redis(
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host=redis_host,
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port=redis_port,
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db=redis_db,
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decode_responses=True,
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socket_keepalive=True
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)
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self.redis.ping()
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logger.info(f"Cache backend initialized: {redis_host}:{redis_port}/db{redis_db}")
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except Exception as e:
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logger.error(f"Cache backend failed: {e}")
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self.redis = None
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self.ttls = {
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'user': 7 * 24 * 3600, # 7 days
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'item_list': 5 * 60, # 5 minutes
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'item_detail': 10 * 60, # 10 minutes
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'borrowing': 60, # 1 minute
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'qrcode': 30 * 24 * 3600, # 30 days
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'search': 2 * 60, # 2 minutes
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'admin_agg': 10 * 60, # 10 minutes
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'filters': 60 * 60, # 1 hour
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}
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def _get_cache_key(self, tenant_id, category, query_hash):
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"""Generate cache key with tenant isolation."""
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return f"cache:{tenant_id}:{category}:{query_hash}"
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def _hash_query(self, query_dict):
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"""Hash MongoDB query for cache key."""
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query_str = json.dumps(query_dict, sort_keys=True, default=str)
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return hashlib.md5(query_str.encode()).hexdigest()[:16]
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def get(self, tenant_id, category, query_dict):
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"""
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Retrieve cached query result.
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Returns None if not cached or expired.
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"""
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if not self.redis:
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return None
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try:
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cache_key = self._get_cache_key(
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tenant_id,
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category,
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self._hash_query(query_dict)
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)
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cached = self.redis.get(cache_key)
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if cached:
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logger.debug(f"Cache HIT: {category} for tenant {tenant_id}")
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return json.loads(cached)
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else:
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logger.debug(f"Cache MISS: {category} for tenant {tenant_id}")
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return None
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except Exception as e:
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logger.error(f"Cache retrieval failed: {e}")
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return None
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def set(self, tenant_id, category, query_dict, result, ttl=None):
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"""
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Cache query result with automatic expiration.
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"""
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if not self.redis:
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return False
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try:
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cache_key = self._get_cache_key(
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tenant_id,
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category,
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self._hash_query(query_dict)
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)
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ttl = ttl or self.ttls.get(category, 5 * 60)
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self.redis.setex(
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cache_key,
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ttl,
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json.dumps(result, default=str)
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)
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logger.debug(f"Cache SET: {category} for tenant {tenant_id} (TTL: {ttl}s)")
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return True
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except Exception as e:
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logger.error(f"Cache write failed: {e}")
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return False
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def invalidate_category(self, tenant_id, category):
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"""
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Invalidate all cache entries in a category for a tenant.
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Called after write operations (insert, update, delete).
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"""
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if not self.redis:
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return False
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try:
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pattern = f"cache:{tenant_id}:{category}:*"
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keys = self.redis.keys(pattern)
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if keys:
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deleted = self.redis.delete(*keys)
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logger.info(f"Invalidated {deleted} cache entries: {category} for tenant {tenant_id}")
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return deleted > 0
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return False
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except Exception as e:
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logger.error(f"Cache invalidation failed: {e}")
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return False
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def invalidate_tenant(self, tenant_id):
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"""
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Completely clear all cache for a tenant.
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Heavy operation - use sparingly.
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"""
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if not self.redis:
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return False
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try:
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pattern = f"cache:{tenant_id}:*"
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keys = self.redis.keys(pattern)
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if keys:
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deleted = self.redis.delete(*keys)
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logger.warning(f"Cleared {deleted} cache entries for tenant {tenant_id}")
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return deleted > 0
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return False
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except Exception as e:
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logger.error(f"Tenant cache clear failed: {e}")
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return False
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def get_stats(self, tenant_id):
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"""
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Get cache statistics for tenant.
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Useful for monitoring.
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"""
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if not self.redis:
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return {}
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try:
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pattern = f"cache:{tenant_id}:*"
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keys = self.redis.keys(pattern)
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stats = {
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'tenant_id': tenant_id,
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'entries': len(keys),
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'memory_bytes': sum(self.redis.memory_usage(k) or 0 for k in keys),
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'categories': {}
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}
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# Count by category
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for key in keys:
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parts = key.split(':')
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if len(parts) >= 3:
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category = parts[2]
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stats['categories'][category] = stats['categories'].get(category, 0) + 1
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return stats
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except Exception as e:
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logger.error(f"Cache stats failed: {e}")
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return {}
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def get_cache_manager():
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"""
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Get or create cache manager for current request.
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Safe to call outside request context.
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"""
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if not has_request_context():
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return None
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if 'cache_manager' not in g:
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from session_manager import create_redis_session_interface
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# Reuse Redis connection if available
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interface = create_redis_session_interface(None)
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if interface.redis:
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# Use separate DB for cache (DB 1 instead of 0 for sessions)
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g.cache_manager = CacheManager(
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redis_client=interface.redis,
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redis_db=1
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)
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else:
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g.cache_manager = CacheManager()
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return g.cache_manager
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def cached_query(category='item_list', ttl=None):
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"""
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Decorator to cache MongoDB query results.
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Usage:
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@cached_query(category='item_list', ttl=300)
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def get_items(db, filters):
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return db['items'].find(filters).to_list(100)
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"""
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def decorator(f):
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@wraps(f)
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def decorated(*args, **kwargs):
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# Extract tenant from context
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from tenant import get_tenant_context
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ctx = get_tenant_context()
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if not ctx or not ctx.tenant_id:
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# No tenant context, execute without caching
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return f(*args, **kwargs)
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# Build query hash from args/kwargs
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query_dict = {'args': str(args), 'kwargs': kwargs}
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# Try cache
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cache_mgr = get_cache_manager()
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if cache_mgr:
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cached_result = cache_mgr.get(ctx.tenant_id, category, query_dict)
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if cached_result is not None:
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return cached_result
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# Execute function
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result = f(*args, **kwargs)
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# Cache result
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if cache_mgr and result:
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cache_mgr.set(ctx.tenant_id, category, query_dict, result, ttl)
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return result
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return decorated
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return decorator
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def invalidate_cache(tenant_id, category):
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"""
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Manually invalidate cache after write operations.
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Usage in app.py:
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# After deleting an item
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invalidate_cache(tenant_id, 'item_list')
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invalidate_cache(tenant_id, 'item_detail')
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"""
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cache_mgr = get_cache_manager()
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if cache_mgr:
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cache_mgr.invalidate_category(tenant_id, category)
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@@ -0,0 +1,190 @@
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"""
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Optimized Session Management using Redis
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Replaces Flask's default filesystem session storage with Redis for:
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- Significantly reduced I/O (no disk writes per request)
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- Multi-instance session sharing (sticky sessions not needed)
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- Automatic cleanup of expired sessions
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- Distributed cache support
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Reduces memory footprint and improves responsiveness across multi-tenant instances.
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"""
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import redis
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import os
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import json
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import secrets
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from datetime import datetime, timedelta
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from flask.sessions import SessionInterface
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from werkzeug.datastructures import CallbackDict
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import logging
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logger = logging.getLogger(__name__)
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class RedisSessionInterface(SessionInterface):
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"""
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Flask session storage backend using Redis.
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Each session is stored as JSON in Redis with automatic expiration.
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Supports distributed deployments with multiple app instances.
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"""
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def __init__(self, redis_client=None, redis_host='redis', redis_port=6379,
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redis_db=0, key_prefix='inventar:session:'):
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"""
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Initialize Redis session interface.
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Args:
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redis_client: Existing redis.Redis instance (optional)
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redis_host: Redis server hostname
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redis_port: Redis server port
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redis_db: Redis database number
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key_prefix: Prefix for all session keys
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"""
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self.redis = redis_client
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if not self.redis:
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try:
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self.redis = redis.Redis(
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host=redis_host,
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port=redis_port,
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db=redis_db,
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decode_responses=True,
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socket_keepalive=True,
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socket_keepalive_options={
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1: 1, # TCP_KEEPIDLE
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2: 1, # TCP_KEEPINTVL
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3: 3, # TCP_KEEPCNT
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} if hasattr(redis, 'TCP_KEEPIDLE') else {}
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)
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# Test connection
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self.redis.ping()
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logger.info(f"Redis session backend initialized: {redis_host}:{redis_port}")
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except Exception as e:
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logger.error(f"Failed to connect to Redis: {e}")
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self.redis = None
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self.key_prefix = key_prefix
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self.permanent_session_lifetime = timedelta(days=7)
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def open_session(self, app, request):
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"""
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Open session: retrieve from Redis or create new.
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Called at the start of each request.
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"""
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if not self.redis:
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# Fallback: return empty session if Redis unavailable
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logger.warning("Redis unavailable, creating in-memory session")
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return {}
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sid = request.cookies.get(app.config.get('SESSION_COOKIE_NAME', 'session'))
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if not sid:
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# New session
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sid = secrets.token_urlsafe(32)
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session = {}
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else:
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# Retrieve from Redis
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try:
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session_key = f"{self.key_prefix}{sid}"
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session_data = self.redis.get(session_key)
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if session_data:
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session = json.loads(session_data)
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else:
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# Session expired or not found
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session = {}
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sid = secrets.token_urlsafe(32)
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except Exception as e:
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logger.error(f"Failed to load session {sid}: {e}")
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session = {}
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sid = secrets.token_urlsafe(32)
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# Wrap in CallbackDict to track modifications
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def save_session(*args):
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self.save_session(app, session, None)
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return CallbackDict(session, save_session)
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def save_session(self, app, session, response):
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"""
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Save session to Redis with auto-expiration.
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Called at the end of each request.
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"""
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if not self.redis or not session:
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return
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sid = response.headers.get('Set-Cookie', '').split('session=')[-1].split(';')[0] if response else None
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if not sid:
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# Generate new session ID
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sid = secrets.token_urlsafe(32)
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try:
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session_key = f"{self.key_prefix}{sid}"
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# Set TTL based on session permanent flag
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ttl = int(self.permanent_session_lifetime.total_seconds())
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# Store session as JSON with expiration
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session_data = json.dumps(session)
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self.redis.setex(session_key, ttl, session_data)
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# Set session cookie if response provided
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if response:
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cookie_secure = app.config.get('SESSION_COOKIE_SECURE', False)
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cookie_httponly = app.config.get('SESSION_COOKIE_HTTPONLY', True)
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cookie_samesite = app.config.get('SESSION_COOKIE_SAMESITE', 'Lax')
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cookie_path = '/'
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response.set_cookie(
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app.config.get('SESSION_COOKIE_NAME', 'session'),
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sid,
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max_age=ttl,
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secure=cookie_secure,
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httponly=cookie_httponly,
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samesite=cookie_samesite,
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path=cookie_path
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)
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except Exception as e:
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logger.error(f"Failed to save session {sid}: {e}")
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def delete_session(self, app, session_id):
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"""
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Manually delete a session from Redis.
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Useful for logout or admin cleanup.
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"""
|
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if not self.redis:
|
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return
|
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|
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try:
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session_key = f"{self.key_prefix}{session_id}"
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self.redis.delete(session_key)
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logger.debug(f"Session deleted: {session_id}")
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except Exception as e:
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logger.error(f"Failed to delete session {session_id}: {e}")
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|
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def create_redis_session_interface(app):
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"""
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Factory function to create and configure Redis session interface for Flask app.
|
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|
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Usage in app.py:
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app.session_interface = create_redis_session_interface(app)
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"""
|
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redis_host = os.getenv('INVENTAR_REDIS_HOST', 'redis')
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redis_port = int(os.getenv('INVENTAR_REDIS_PORT', 6379))
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redis_db = int(os.getenv('INVENTAR_REDIS_DB', 0))
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interface = RedisSessionInterface(
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redis_host=redis_host,
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redis_port=redis_port,
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redis_db=redis_db,
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key_prefix='inventar:session:'
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)
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if not interface.redis:
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logger.warning("Redis session backend failed to initialize, using fallback")
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return interface
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+147
@@ -0,0 +1,147 @@
|
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"""
|
||||
Multi-Tenant Context Manager
|
||||
|
||||
Handles tenant resolution, isolation, and database routing for multi-tenant deployments.
|
||||
Supports subdomain-based tenant identification and per-tenant database namespacing.
|
||||
|
||||
Each tenant can support up to 20+ users with isolated data and resource pools.
|
||||
"""
|
||||
|
||||
from flask import request, g, has_request_context
|
||||
from functools import wraps
|
||||
import logging
|
||||
|
||||
logger = logging.getLogger(__name__)
|
||||
|
||||
# Tenant registry: maps subdomain/tenant_id to database name
|
||||
TENANT_REGISTRY = {}
|
||||
|
||||
|
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class TenantContext:
|
||||
"""
|
||||
Manages current tenant context for request lifecycle.
|
||||
Automatically resolves tenant from subdomain or request header.
|
||||
"""
|
||||
|
||||
def __init__(self):
|
||||
self.tenant_id = None
|
||||
self.db_name = None
|
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self.subdomain = None
|
||||
|
||||
def resolve_tenant(self):
|
||||
"""
|
||||
Resolve tenant from request context.
|
||||
Priority: Header > Subdomain > Default
|
||||
"""
|
||||
if not has_request_context():
|
||||
return None
|
||||
|
||||
# Priority 1: X-Tenant-ID header (for testing/internal APIs)
|
||||
tenant_from_header = request.headers.get('X-Tenant-ID', '').strip()
|
||||
if tenant_from_header:
|
||||
self.tenant_id = tenant_from_header
|
||||
return self._get_db_name(tenant_from_header)
|
||||
|
||||
# Priority 2: Subdomain extraction
|
||||
host = request.host.lower()
|
||||
parts = host.split('.')
|
||||
|
||||
# Extract subdomain from host
|
||||
# Examples: schule1.example.com → schule1
|
||||
# app.example.com → app (skip wildcard/app)
|
||||
if len(parts) >= 3:
|
||||
potential_subdomain = parts[0]
|
||||
|
||||
# Filter out common non-tenant subdomains
|
||||
if potential_subdomain not in ('www', 'api', 'admin', 'app', 'mail'):
|
||||
self.subdomain = potential_subdomain
|
||||
self.tenant_id = potential_subdomain
|
||||
return self._get_db_name(potential_subdomain)
|
||||
|
||||
# Fallback to default tenant if no subdomain detected
|
||||
self.tenant_id = 'default'
|
||||
return self._get_db_name('default')
|
||||
|
||||
def _get_db_name(self, tenant_id):
|
||||
"""
|
||||
Get MongoDB database name for tenant.
|
||||
Format: inventar_<tenant_id>
|
||||
"""
|
||||
# Sanitize tenant_id for MongoDB database name
|
||||
sanitized = ''.join(c if c.isalnum() or c == '_' else '' for c in tenant_id.lower())
|
||||
db_name = f"inventar_{sanitized}"
|
||||
self.db_name = db_name
|
||||
return db_name
|
||||
|
||||
def get_database(self, mongo_client):
|
||||
"""
|
||||
Get MongoDB database instance for current tenant.
|
||||
"""
|
||||
if not self.db_name:
|
||||
self.resolve_tenant()
|
||||
return mongo_client[self.db_name]
|
||||
|
||||
|
||||
def get_tenant_context():
|
||||
"""
|
||||
Get or create tenant context for current request.
|
||||
Safe to call outside request context; returns None.
|
||||
"""
|
||||
if not has_request_context():
|
||||
return None
|
||||
|
||||
if 'tenant_context' not in g:
|
||||
g.tenant_context = TenantContext()
|
||||
g.tenant_context.resolve_tenant()
|
||||
|
||||
return g.tenant_context
|
||||
|
||||
|
||||
def require_tenant(f):
|
||||
"""
|
||||
Decorator to enforce tenant context resolution before route handler.
|
||||
Automatically injects tenant context into g.tenant_context.
|
||||
"""
|
||||
@wraps(f)
|
||||
def decorated_function(*args, **kwargs):
|
||||
ctx = get_tenant_context()
|
||||
if not ctx or not ctx.tenant_id:
|
||||
logger.warning(f"Request to {request.path} missing tenant context")
|
||||
# Fallback to 'default' tenant
|
||||
ctx = TenantContext()
|
||||
ctx.resolve_tenant()
|
||||
g.tenant_context = ctx
|
||||
|
||||
return f(*args, **kwargs)
|
||||
|
||||
return decorated_function
|
||||
|
||||
|
||||
def get_tenant_db(mongo_client):
|
||||
"""
|
||||
Convenience helper to get tenant-specific database.
|
||||
Usage: db = get_tenant_db(mongo_client)
|
||||
"""
|
||||
ctx = get_tenant_context()
|
||||
if ctx:
|
||||
return ctx.get_database(mongo_client)
|
||||
# Fallback to default database
|
||||
return mongo_client['inventar_default']
|
||||
|
||||
|
||||
def register_tenant(tenant_id, config=None):
|
||||
"""
|
||||
Register a new tenant in the system.
|
||||
Typically called during tenant provisioning.
|
||||
|
||||
Args:
|
||||
tenant_id: Unique tenant identifier (e.g., 'schule1')
|
||||
config: Optional tenant-specific configuration
|
||||
"""
|
||||
TENANT_REGISTRY[tenant_id] = config or {}
|
||||
logger.info(f"Tenant registered: {tenant_id}")
|
||||
|
||||
|
||||
def list_registered_tenants():
|
||||
"""Return list of all registered tenants."""
|
||||
return list(TENANT_REGISTRY.keys())
|
||||
Reference in New Issue
Block a user