NULL being passed from pipeline to linked service baseURL - azure-data-factory

Question

I have a pipeline that will iterate over files and copy them to a storage location.
The baseURL and relativeURL are stored in a json file.
I can read in this file and it is valid.
I have parameterized the linked service baseURL and this works when testing from the linked service, and from the dataset.
When I try to debug the pipeline however, I get an error:
"code":"BadRequest"
"message":null
"target":"pipeline//runid/310b8ac1-2ce6-4c7c-a1ad-433ee9019e9b"
"details":null
"error":null
It appears that from the activity in the pipeline, a null value is being passed instead of the baseURL.
I have iterated over the values from my config file and it is being read and the values are correct. It really seems like the pipeline is not passing in the correct value for baseURL.
Do I have to modify the json code behind the pipeline to get this to work?
If it helps, the json for the linked service, data set and pipeline are below:
--Linked Service:
{
"name": "ls_http_opendata_ecdc_europe_eu",
"properties": {
"parameters": {
"baseURL": {
"type": "string"
}
},
"annotations": [],
"type": "HttpServer",
"typeProperties": {
"url": "#linkedService().baseURL",
"enableServerCertificateValidation": true,
"authenticationType": "Anonymous"
}
}
}
--dataset
{
"name": "ds_ecdc_raw_csv_http",
"properties": {
"linkedServiceName": {
"referenceName": "ls_http_opendata_ecdc_europe_eu",
"type": "LinkedServiceReference"
},
"parameters": {
"relativeURL": {
"type": "string"
},
"baseURL": {
"type": "string"
}
},
"annotations": [],
"type": "DelimitedText",
"typeProperties": {
"location": {
"type": "HttpServerLocation",
"relativeUrl": {
"value": "#dataset().relativeURL",
"type": "Expression"
}
},
"columnDelimiter": ",",
"escapeChar": "\\",
"firstRowAsHeader": true,
"quoteChar": "\""
},
"schema": []
}
}
--pipeline
{
"name": "pl_ingest_ecdc_data",
"properties": {
"activities": [
{
"name": "lookup ecdc filelist",
"type": "Lookup",
"dependsOn": [],
"policy": {
"timeout": "7.00:00:00",
"retry": 0,
"retryIntervalInSeconds": 30,
"secureOutput": false,
"secureInput": false
},
"userProperties": [],
"typeProperties": {
"source": {
"type": "JsonSource",
"storeSettings": {
"type": "AzureBlobStorageReadSettings",
"recursive": true,
"enablePartitionDiscovery": false
},
"formatSettings": {
"type": "JsonReadSettings"
}
},
"dataset": {
"referenceName": "ds_ecdc_file_list",
"type": "DatasetReference"
},
"firstRowOnly": false
}
},
{
"name": "execute copy for every record",
"type": "ForEach",
"dependsOn": [
{
"activity": "lookup ecdc filelist",
"dependencyConditions": [
"Succeeded"
]
}
],
"userProperties": [],
"typeProperties": {
"items": {
"value": "#activity('lookup ecdc filelist').output.value",
"type": "Expression"
},
"activities": [
{
"name": "Copy data1",
"type": "Copy",
"dependsOn": [],
"policy": {
"timeout": "7.00:00:00",
"retry": 0,
"retryIntervalInSeconds": 30,
"secureOutput": false,
"secureInput": false
},
"userProperties": [],
"typeProperties": {
"source": {
"type": "DelimitedTextSource",
"storeSettings": {
"type": "HttpReadSettings",
"requestMethod": "GET"
},
"formatSettings": {
"type": "DelimitedTextReadSettings"
}
},
"sink": {
"type": "DelimitedTextSink",
"storeSettings": {
"type": "AzureBlobFSWriteSettings"
},
"formatSettings": {
"type": "DelimitedTextWriteSettings",
"quoteAllText": true,
"fileExtension": ".txt"
}
},
"enableStaging": false,
"translator": {
"type": "TabularTranslator",
"typeConversion": true,
"typeConversionSettings": {
"allowDataTruncation": true,
"treatBooleanAsNumber": false
}
}
},
"inputs": [
{
"referenceName": "DelimitedText1",
"type": "DatasetReference",
"parameters": {
"sourceBaseURL": {
"value": "#item().sourceBaseURL",
"type": "Expression"
},
"sourceRelativeURL": {
"value": "#item().sourceRelativeURL",
"type": "Expression"
}
}
}
],
"outputs": [
{
"referenceName": "ds_ecdc_raw_csv_dl",
"type": "DatasetReference",
"parameters": {
"fileName": {
"value": "#item().sinkFileName",
"type": "Expression"
}
}
}
]
}
]
}
}
],
"concurrency": 1,
"annotations": []
}
}

Answer 1

I reproduced your error.
{"code":"BadRequest","message":null,"target":"pipeline//runid/abd35329-3625-490b-85cf-f6d0de3dac86","details":null,"error":null}
It is because you didn't pass your baseURL to link service in Source Dataset. Please do this:
And Dataset JSON code should be like this:
{
"name": "ds_ecdc_raw_csv_http",
"properties": {
"linkedServiceName": {
"referenceName": "ls_http_opendata_ecdc_europe_eu",
"type": "LinkedServiceReference",
"parameters": {
"baseURL": {
"value": "#dataset().baseURL",
"type": "Expression"
}
}
},
"parameters": {
"relativeURL": {
"type": "string"
},
"baseURL": {
"type": "string"
}
},
"annotations": [],
"type": "DelimitedText",
"typeProperties": {
"location": {
"type": "HttpServerLocation",
"relativeUrl": {
"value": "#dataset().relativeURL",
"type": "Expression"
}
},
"columnDelimiter": ",",
"escapeChar": "\\",
"firstRowAsHeader": true,
"quoteChar": "\""
},
"schema": []
}
}