elasticsearch - Elasticsearch管道无法访问@myfield

Question

在创建文档时，我想访问一个以“@”开头的字段。
文档将通过以下方式添加:

POST http://localhost:9200/myindex/_doc?pipeline=test_pipeline
{
"name":"Joe",
"@myfield":"field value"
}

甚至无法添加这样的管道，它会引发编译错误(使用不带“@”的字段效果很好)

{
    "description": "describe pipeline",
    "processors": [
        {
            "script": {
                "ignore_failure": false,
                "lang": "painless",
                "source": "ctx._id= ctx.@myfield"
            }
        }
    ]
}

尝试此处描述的解决方案https://discuss.elastic.co/t/painless-how-to-access-timestamp-field-in-script/130263

{
    "description": "describe pipeline",
    "processors": [
        {
            "script": {
                "ignore_failure": false,
                "lang": "painless",
                "source": "ctx._id= ctx._source['@myfield']"
            }
        }
    ]
}

这样可以成功创建管道，但是以上述方式添加文档将失败，并引发NPE:

 "type": "script_exception",
        "reason": "runtime error",
        "script_stack": [
            "ctx._id= ctx._source['@myfield']",
            "            ^---- HERE"
        ],
        "script": "ctx._id= ctx._source['@myfield']",
        "lang": "painless",
        "position": {
            "offset": 12,
            "start": 0,
            "end": 34
        },
        "caused_by": {
            "type": "null_pointer_exception",
            "reason": "Cannot invoke \"Object.getClass()\" because \"callArgs[0]\" is null"
        }

Answer 1

这有效:"source": "ctx._id= ctx['@myfield']"ctx._source仅在使用更新，按查询更新或重新索引API时可以访问
来源:
https://www.elastic.co/guide/en/elasticsearch/reference/master/modules-scripting-fields.html