Problem creating eventhub consumer-group (IOT-hub, 2021-03-03-preview API)

[ramondeklein]

The IotHubResourceClient.CreateEventHubConsumerGroup function requires a EventHubConsumerGroupBodyDescription object that is sent in the body. This structure isn't documented and has been added in 2021-03-03-preview. It seems that it should also contain the consumer-group name (as seen in this example). This seems redundant (it's already in the URL), but to be able to use the SDK I send the name of the consumer-group too.

I have issued a request to create a consumer-group that generates the following request (I have removed the subscription-id for privacy reasons and formatted the JSON data for clarity):

PUT /subscriptions/<subscription-id>/resourceGroups/acctestRG-210913193521490604/providers/Microsoft.Devices/IotHubs/acctestIoTHub-210913193521490604/eventHubEndpoints/events/ConsumerGroups/test?api-version=2021-03-03-preview HTTP/1.1
Host: management.azure.com
User-Agent: Go/go1.17 (amd64-linux) go-autorest/v14.2.1 Azure-SDK-For-Go/v57.0.0 devices/2021-03-03-preview HashiCorp Terraform/1.0.6 (+https://www.terraform.io) Terraform Plugin SDK/2.7.0 terraform-provider-azurerm/acc pid-222c6c49-1b0a-5959-a213-6608f9eb8820
Content-Length: 30
Content-Type: application/json; charset=utf-8
X-Ms-Correlation-Request-Id: 4e53d1f1-985b-1630-12b2-1d9c72fc0c57
Accept-Encoding: gzip

{
  "properties": {
    "name": "test"
  }
}

The name is sent in the body and the response is processed correctly, because the following response is received:

HTTP/2.0 200 OK
Cache-Control: no-cache
Content-Type: application/json; charset=utf-8
Date: Mon, 13 Sep 2021 17:38:03 GMT
Expires: -1
Pragma: no-cache
Server: Microsoft-HTTPAPI/2.0
Strict-Transport-Security: max-age=31536000; includeSubDomains
Vary: Accept-Encoding
X-Content-Type-Options: nosniff
X-Ms-Correlation-Request-Id: 4e53d1f1-985b-1630-12b2-1d9c72fc0c57
X-Ms-Ratelimit-Remaining-Subscription-Writes: 1198
X-Ms-Request-Id: 472d6a96-c40d-4dfa-9bd3-194cfa1bac87
X-Ms-Routing-Request-Id: WESTEUROPE:20210913T173803Z:472d6a96-c40d-4dfa-9bd3-194cfa1bac87

{
  "properties": {
    "created": "Mon, 13 Sep 2021 17:38:03 GMT",
    "properties": {
      "name": "test"
    }
  },
  "id": "/subscriptions/<subscription-id>/resourceGroups/acctestRG-210913193521490604/providers/Microsoft.Devices/IotHubs/acctestIoTHub-210913193521490604/eventHubEndpoints/events/ConsumerGroups/test",
  "name": "test",
  "type": "Microsoft.Devices/IotHubs/EventHubEndpoints/ConsumerGroups",
  "etag": null
}

There seems to be an issue with the returned properties field in the response. The entire response is unmarshalled into the EventHubConsumerGroupInfo structure:

type EventHubConsumerGroupInfo struct {
    autorest.Response `json:"-"`
    Properties map[string]*string `json:"properties"`
    ID *string `json:"id,omitempty"`
    Name *string `json:"name,omitempty"`
    Type *string `json:"type,omitempty"`
    Etag *string `json:"etag,omitempty"`
}

The structure contains the properties field, but it's marked as map[string]*string. The API returns a properties field that also embeds the input properties map, so this can't be deserialized and fails. I guess it's a buck in the API back-end, because it seems pretty useless to have properties within properties, but I did also check the .NET SDK and it defines the properties like this:

[JsonProperty(PropertyName = "properties")]
public IDictionary<string, object> Properties { get; set; }

I guess creating consumer-groups is broken with the 2021-03-03-preview API. I also am wondering why the name should also be sent in the request body.

[tadelesh]

Thank you for your feedback. As for the CreateEventHubConsumerGroup unmarshall crash, we will resolve it by next SDK release which will upgrade iothub api version to 2021-03-31.

[tadelesh]

@ramondeklein We have released v57.4.0, you can try new api version: github.com/Azure/azure-sdk-for-go/services/iothub/mgmt/2021-03-31/devices. Have fun, thanks.

[ramondeklein]

Works fine.