javascript - 如何在带有Node.js的Elasticsearch中的聚合中使用自定义脚本

Question

这是我的代码:

const convertCurrency = async (currrencyType)  => {
    try{
        const res =  await got("https://api.exchangerate-api.com/v4/latest/USD");
        return (JSON.parse(res.body)['rates'][currrencyType]);
    }
    catch(err){
        console.log(err);
    }
}

async function search(){
  try{
    client.search({
      index : '03776182',
      body: {
        aggs : {
          price_ranges : {
              range : {
                  field : "price",
                  script : {source : "convertCurrency(/EUR/) * _value"},
                  ranges : [
                      { "from" : 10, "to" : 20 },
                  ]
              }
          }
      }
      }
  },(err,resp,status)=>{
      err ? console.log(err): console.log(JSON.stringify(resp));
  });
  }
  catch(err){console.log(err);}
}

我正在尝试在源字段中插入自定义脚本。但是它给出了以下错误。

 response: `{"error":{"root_cause":[{"type":"script_exception","reason":"compile error","script_stack":["convertCurrency(/EUR/) * _value","                ^---- HERE"],"script":"convertCurrency(/EUR/) * _value","lang":"painless"}],"type":"search_phase_execution_exception","reason":"all shards failed","phase":"query","grouped":true,"failed_shards":[{"shard":0,"index":"03776182","node":"C4p_ha96QhK2uB47jV9pxg","reason":{"type":"script_exception","reason":"compile error","script_stack":["convertCurrency(/EUR/) * _value","                ^---- HERE"],"script":"convertCurrency(/EUR/) * _value","lang":"painless","caused_by":{"type":"illegal_state_exception","reason":"Regexes are disabled. Set [script.painless.regex.enabled] to [true] in elasticsearch.yaml to allow them. Be careful though, regexes break out of Painless's protection against deep recursion and long loops."}}}]},"status":500}`,
  toString: [Function],

同时正常表达效果很好。

Answer 1

您不能从ES脚本调用JS回调，这没有意义，因为它们不在同一上下文中执行。

您应该做的是首先在Node.js代码中检索欧元汇率，然后将以该汇率作为参数的查询发送到脚本。

在伪代码中，它看起来像这样:

// 1. retrieve EUR/USD exchange rate
const EUR_USD = convertCurrency('EUR');

// 2. send your query
client.search({
  index : '03776182',
  body: {
    aggs : {
      price_ranges : {
          range : {
              field : "price",
              script : {
                 source : "params.rate * _value"
                 params: { 
                    rate: EUR_USD
                 }
              },
              ranges : [
                  { "from" : 10, "to" : 20 },
              ]
          }
      }
  }
  }