Data Fusion - Argument Setter plugin throws Null pointer exception - google-cloud-platform

Question

Argument setter - HTTP post endpoint url.
Below is the argument setter plugin configuration.
{
"name": "Argument Setter",
"plugin": {
"name": "ArgumentSetter",
"type": "action",
"label": "Argument Setter",
"artifact": {
"name": "argument-setter-plugins",
"version": "1.1.1",
"scope": "USER"
},
"properties": {
"method": "POST",
"connectTimeout": "60000",
"readTimeout": "60000",
"numRetries": "0",
"followRedirects": "true",
"url": "-----url----",
"body": "{\"type\": \"DELTA\", \"fileType\": \"CSV\", \"targetName\": \"DATAFUSION_TEST_1\", \"dataPoolId\": \"4d3164d9-c8e4-4042-9c69-ff758a17b140\"}"
}
},
"outputSchema": [
{
"name": "id",
"type": "string",
"nullable" : true
},
{
"name": "targetName",
"type": "string",
"nullable" : true
},
{
"name": "lastModified",
"type": "int",
"nullable" : true
},
{
"name": "lastPing",
"type": "string",
"nullable" : true
},
{
"name": "status",
"type": "string",
"nullable" : true
},
{
"name": "type",
"type": "string",
"nullable" : true
},
{
"name": "fileType",
"type": "string",
"nullable" : true
},
{
"name": "targetSchema",
"type": "string",
"nullable" : true
},
{
"name": "upsertStrategy",
"type": "string",
"nullable" : true
},
{
"name": "fallbackVarcharLength",
"type": "string",
"nullable" : true
},
{
"name": "dataPoolId",
"type": "string",
"nullable" : true
},
{
"name": "connectionId",
"type": "string",
"nullable" : true
},
{
"name": "postExecutionQuery",
"type": "string",
"nullable" : true
},
{
"name": "sanitizedPostExecutionQuery",
"type": "string",
"nullable" : true
},
{
"name": "allowDuplicate",
"type": "boolean",
"nullable" : true
},
{
"name": "tableSchema",
"type": "string",
"nullable" : true
},
{
"name": "mirrorTargetNames",
"type": "array",
"nullable" : true
},
{
"name": "changeDate",
"type": "int",
"nullable" : true
},
{
"name": "keys",
"type": "array",
"nullable" : true
},
{
"name": "logs",
"type": "array",
"nullable" : true
},
{
"name": "csvParsingOptions",
"type": "string",
"nullable" : true
},
{
"name": "optionalTenantId",
"type": "string",
"nullable" : true
}
]
}
],
Response from the endpoint url is like below
[{
"id": "b489dc71-96fd-4e94-bcc5-9a4b3732855e",
"targetName": "POSTMAN_TBL",
"lastModified": 1631598169840,
"lastPing": null,
"status": "NEW",
"type": "DELTA",
"fileType": "PARQUET",
"targetSchema": null,
"upsertStrategy": "UPSERT_WITH_UNCHANGED_METADATA",
"fallbackVarcharLength": null,
"dataPoolId": "f37b8619-30e2-4804-9355-38d123142ac4",
"connectionId": null,
"postExecutionQuery": null,
"sanitizedPostExecutionQuery": null,
"allowDuplicate": false,
"tableSchema": null,
"changeDate": 1631598169840,
"mirrorTargetNames": [],
"keys": [],
"logs": [],
"csvParsingOptions": null,
"optionalTenantId": null
}
]
When I execute this, I get 200 response after hitting the endpoint url.
But the pipeline is failing with NullPointerException
java.lang.NullPointerException: null
at io.cdap.plugin.ArgumentSetter.handleResponse(ArgumentSetter.java:73) ~[na:na]
at io.cdap.plugin.http.HTTPArgumentSetter.run(HTTPArgumentSetter.java:76) ~[na:na]
at io.cdap.cdap.etl.common.plugin.WrappedAction.lambda$run$1(WrappedAction.java:49) ~[na:na]
Can someone help me what am I missing here?

Answer 1

As mentioned in the comments, the response from the server has to be structured in the following format:
{
"arguments" : [
{ argument }, { argument }, ..., {argument}
]
}
Since your response is not structured in this format, you are getting a NullPointerException when you execute your pipeline.
See docs for reference https://github.com/data-integrations/argument-setter/tree/9f6aabbf28e00644726d485188235b406cac522f#usage