A very aggressive stupid caching reverse proxy (belligerent caching?).

Designed to be used with KairosDB to alleviate load on Kairos/Cassandra.

Caches response body from POST requests for 5 minutes, returns body from cache on identical requests.

###Usage:
./postcache -b 'kairosdb.example.com:8080' ####Flags:

• -b 127.0.0.1:8080
  • the host to forward requests to
• -l 8081
  • port to listen on
• -r 127.0.0.1:6379
  • address of redis-server (if redisCache cacher is used)
• -e 7200
  • TTL of keys in redis (seconds)
• -f 300
  • Age of cache before it is considered STALE and updated (seconds)

Cache hit/miss can be seen via headers

X-Postcache: [HIT, MISS, STALE]

• HIT: 'fresh' cache found in redis, returned without triggering refresh
• MISS: no cache found, request passed through to backend, cache updated
• STALE: cache found, but expired, returned 'stale' cache and trigger async refresh