Simple Reindex script using the Elasticsearch Reindex API, loop over a month, for each day print respective index and create target index for reindex. The target index has only 1 shard.

reindex.py

import requests
from datetime import timedelta, date

def daterange(start_date, end_date):
    for n in range(int ((end_date - start_date).days)):
        yield start_date + timedelta(n)

headers={'Content-Type', 'application/json'}
base_url='http://elasticsearch:9200'

start_date=date(2017, 5, 7)
end_date=date(2017, 5, 31)

for single_date in daterange(start_date, end_date):
    current_day = single_date.strftime("%Y.%m.%d")
    
    r = requests.get(base_url + '/_cat/indices/fo-log-' + current_day, auth=('le-mapper', 'MapperKing'))
    print r.text

    r = requests.put(base_url + '/fo-log-fix-' + current_day, auth=('le-mapper', 'MapperKing'), json={"settings":{"index.routing.allocation.require.box_type":"superhot","number_of_shards":1,"number_of_replicas":0,"refresh_interval":-1}})
    print r.text

    r = requests.post(base_url + '/_reindex', auth=('le-mapper', 'MapperKing'), json={"source":{"index":"fo-log-" + current_day },"dest":{"index":"fo-log-fix-" + current_day,"pipeline":"improve"}})
    print r.text