ElasticSeach: force to allocate a primary shard

es-shard-allocate.py

#!/usr/bin/env python3
# script will force to allocate unassigned shards in the cluster
# based on: https://www.elastic.co/guide/en/elasticsearch/reference/5.6/cluster-reroute.html
import urllib.request
import json

host = 'http://es-main-master2-gew2-staging'
destination_host = 'es-main-data2-gew2-staging'

shards_uri = ':9200/_cat/shards?h=index,shard,prirep,state,unassigned.reason&format=json'
reroute_uri = ':9200/_cluster/reroute'

with urllib.request.urlopen(host + shards_uri) as url:
    data = json.loads(url.read().decode())
    for shard in data:
        if (shard['state'] != 'UNASSIGNED' and shard['unassigned.reason'] != 'CLUSTER_RECOVERED') or shard['prirep'] == 'r':
            continue
        print("Shard:", shard)        
        data = {
            "commands": [
                {
                    "allocate_stale_primary": {
                        "index": shard['index'],
                        "shard": int(shard['shard']),
                        "node": destination_host,
                        "accept_data_loss": True
                    }
                }
            ]
        }
        print("Request:", data)
        req = urllib.request.Request(host + reroute_uri)
        req.add_header('Content-Type', 'application/json')

        encoded_data = json.dumps(data).encode('utf8')
        response = urllib.request.urlopen(req, encoded_data)
        print("Response:", response.code)