es_stats.py

import sys, json, functools, time

if sys.stdin.isatty():
  data = json.loads(file("/tmp/status").read())
else:
  data = json.loads(sys.stdin.read())

bytes = 0
docs = 0
shardn = 0
for name, vals in data["indices"].items():
    for i, replicas in vals["shards"].items():
        for r in replicas:
            if r["routing"]["primary"] == True:
                bytes += r["index"]["size_in_bytes"]
                docs += r["docs"]["num_docs"]
                shardn += 1

try:
    bytes_per_doc = bytes/docs
except ZeroDivisionError:
    bytes_per_doc = 0

print int(time.time()), shardn, bytes, docs, bytes_per_doc