1. scene
The

production environment requires writing to a large number of json files, inserting an attribute in the specified node. As follows:

{
    "dataSources":{
        "test_dataSource_hod":{
            "spec":{
                "dataSchema":{
                    "dataSource":"test_dataSource_hod",
                    "parser":{
                        "type":"string",
                        "parseSpec":{
                            "timestampSpec":{
                                "column":"timestamp",
                                "format":"yyyy-MM-dd HH:mm:ss"
                            },
                            "dimensionsSpec":{
                                "dimensions":[
                                    "method",
                                    "key"
                                ]
                            },
                            "format":"json"
                        }
                    },
                    "granularitySpec":{
                        "type":"uniform",
                        "segmentGranularity":"hour",
                        "queryGranularity":"none"
                    },
                    "metricsSpec":[
                        {
                            "name":"count",
                            "type":"count"
                        },
                        {
                            "name":"call_count",
                            "type":"longSum",
                            "fieldName":"call_count"
                        },
                        {
                            "name":"succ_count",
                            "type":"longSum",
                            "fieldName":"succ_count"
                        },
                        {
                            "name":"fail_count",
                            "type":"longSum",
                            "fieldName":"fail_count"
                        }
                    ]
                },
                "ioConfig":{
                    "type":"realtime"
                },
                "tuningConfig":{
                    "type":"realtime",
                    "maxRowsInMemory":"100000",
                    "intermediatePersistPeriod":"PT10M",
                    "windowPeriod":"PT10M"
                }
            },
            "properties":{
                "task.partitions":"1",
                "task.replicants":"1",
                "topicPattern":"test_topic"
            }
        }
    },
    "properties":{
        "zookeeper.connect":"zookeeper.com:2015",
        "druid.discovery.curator.path":"/druid/discovery",
        "druid.selectors.indexing.serviceName":"druid/overlord",
        "commit.periodMillis":"12500",
        "consumer.numThreads":"1",
        "kafka.zookeeper.connect":"kafkaka.com:2181,kafka.com:2181,kafka.com:2181",
        "kafka.group.id":"test_dataSource_hod_dd"
    }
}

needs to be at the end of the properties node to add a "druidBeam. RandomizeTaskId" : "true" property.

2. Ideas

the general idea is as follows:

1. scan all files to be changed
2. confirm the position to be changed
3. insert new character

in the file

where I find it a little bit harder is where I confirm the insertion location. We know is "druid. Selectors. Indexing. The serviceName" : "druid/overlord", this thing must be in the node, that as long as I can find this stuff, and then in his behind with respect to OK.
ok, we've got the idea, let's write the code.

#!/usr/bin/python
# coding:utf-8

import os


old_string = '"druid/overlord"'
new_string = ('"druid/overlord",' +
              '\n        ' +
              '"druidBeam.randomizeTaskId":"true",')


def insertrandomproperty(file_name):
    if '.json' in file_name:
        with open(file, 'r') as oldfile:
            content = oldfile.read()
            checkandinsert(content, file)

    else:
        pass


def checkandinsert(content, file):
    if 'druidBeam.randomizeTaskId' not in content:
       # to avoid ^M appear in the new file because of different os
       # we replace \r  with '' 
        new_content = content.replace(old_string, new_string).replace('\r', '')

        with open(file, 'w') as newfile:
            newfile.write(new_content)
    else:
        pass


if __name__ == '__main__':
    files = os.listdir('/home/tranquility/conf/service_bak')
    os.chdir('/home/tranquility/conf/service_bak')
    for file in files:
        insertrandomproperty(file)

is just updating the content in memory, and then rewriting it back to the file. The code is just a rough representation of the idea and can be modified and optimized as needed.