獲取ElasticSearch索引列表

查詢索引列表信息並格式化為json：

http://127.0.0.1:9021/_cat/indices?format=json&index=[索引名稱，可使用通配符]

執行后獲取到的結果集如下：

[
    {
        "health": "green",
        "status": "open",
        "index": "[此處為你的索引名稱]",
        "uuid": "towtsSEnQR6hqOTDDsWdig",
        "pri": "5",
        "rep": "1",
        "docs.count": "25",
        "docs.deleted": "0",
        "store.size": "258.4kb",
        "pri.store.size": "258.4kb"
    },
    {
        ......
    }
]