lolly/docs/lua/caching

Nginx Lua Caching Example

Demonstrates response caching using ngx.shared.DICT with TTL and cache invalidation support.

Components

File	Purpose
nginx.conf	Nginx configuration wiring Lua handlers
cache_handler.lua	Shared cache logic with TTL and invalidation

Features

• Cache responses with configurable TTL
• Manual cache invalidation via purge endpoint
• X-Cache header (HIT/MISS) for debugging
• LRU eviction when memory is full

Usage

1. Define a shared dict in nginx.conf:

   lua_shared_dict response_cache 10m;
   

2. Use cache_handler.lua in your location blocks:

   content_by_lua_file /path/to/cache_handler.lua;
   

3. Purge a specific cache key:

   curl -X POST http://example.com/cache/purge -d '{"key": "my_key"}'
   

4. Purge all cached entries:

   curl -X POST http://example.com/cache/purge_all