[BUG] Microsoft.MachineLearningServices @ 2024-04-01 - applicationInsights on a Hub is returned as null when an associated Project is updated

[stephybun]

API Spec link

azure-rest-api-specs/specification/machinelearningservices/resource-manager/Microsoft.MachineLearningServices/stable/2024-04-01/workspaceRP.json

Lines 1702 to 1704 in edc6e6a

	"applicationInsights": {
	"description": "ARM id of the application insights associated with this workspace.",
	"type": "string"

API Spec version

2024-01-01

Describe the bug

The API returns a null for the Application Insights ID on a Hub after a Project associated with the Hub has been updated

I've added the order of REST API calls done to reproduce the behaviour. The issue is highlighted in the last API call where we get the Hub after the associated Project was updated.

Creation PUT of the AI Hub

{
  "identity": {
    "type": "UserAssigned",
    "userAssignedIdentities": {
      "/subscriptions/000000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.ManagedIdentity/userAssignedIdentities/acctestuai-241128132257385881": {}
    }
  },
  "kind": "Hub",
  "location": "westeurope",
  "name": "acctestaihub-241128132257385881",
  "properties": {
    "applicationInsights": "/subscriptions/000000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.Insights/components/acctestai-241128132257385881",
    "containerRegistry": "/subscriptions/000000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.ContainerRegistry/registries/testacccr241128132257385881",
    "description": "AI Hub created by Terraform",
    "friendlyName": "AI Hub",
    "hbiWorkspace": true,
    "imageBuildCompute": "buildtest",
    "keyVault": "/subscriptions/000000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.KeyVault/vaults/acctestvault9tcd0",
    "managedNetwork": {
      "isolationMode": "AllowInternetOutbound"
    },
    "primaryUserAssignedIdentity": "/subscriptions/000000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.ManagedIdentity/userAssignedIdentities/acctestuai-241128132257385881",
    "publicNetworkAccess": "Disabled",
    "storageAccount": "/subscriptions/000000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.Storage/storageAccounts/acctestsa9tcd0"
  },
  "tags": {
    "env": "test"
  }
}

Creation PUT of the AI Project

{
  "identity": {
    "type": "SystemAssigned",
    "userAssignedIdentities": null
  },
  "kind": "Project",
  "location": "westeurope",
  "name": "acctestaip-241128132257385881",
  "properties": {
    "description": "AI Project created by Terraform",
    "friendlyName": "AI Project",
    "hubResourceId": "/subscriptions/00000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.MachineLearningServices/workspaces/acctestaihub-241128132257385881",
    "imageBuildCompute": "projectbuild"
  },
  "tags": {
    "model": "regression"
  }
}

GET on the parent AI Hub after Project was created

{
  "id": "/subscriptions/00000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.MachineLearningServices/workspaces/acctestaihub-241128132257385881",
  "name": "acctestaihub-241128132257385881",
  "type": "Microsoft.MachineLearningServices/workspaces",
  "location": "westeurope",
  "tags": {
    "env": "test"
  },
  "etag": null,
  "properties": {
    "friendlyName": "AI Hub",
    "description": "AI Hub created by Terraform",
    "storageAccount": "/subscriptions/00000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.Storage/storageAccounts/acctestsa9tcd0",
    "keyVault": "/subscriptions/00000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.KeyVault/vaults/acctestvault9tcd0",
    "applicationInsights": "/subscriptions/00000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.Insights/components/acctestai-241128132257385881",
    "hbiWorkspace": true,
    "tenantId": "00000",
    "imageBuildCompute": "buildtest",
    "provisioningState": "Succeeded",
    
...

    "associatedWorkspaces": [
      "/subscriptions/00000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.MachineLearningServices/workspaces/acctestaip-241128132257385881"
    ],
    "workspaceHubConfig": {
      "defaultWorkspaceResourceGroup": "/subscriptions/00000/resourceGroups/acctestRG-aiservices-241128132257385881"
    },
    "enableDataIsolation": true
  },
  "identity": {
    "type": "UserAssigned",
    "principalId": null,
    "tenantId": "00000",
    "userAssignedIdentities": {
      "/subscriptions/00000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.ManagedIdentity/userAssignedIdentities/acctestuai-241128132257385881": {
        "principalId": "00000",
        "clientId": "00000"
      }
    }
  },
  "kind": "Hub",
  "sku": {
    "name": "Basic",
    "tier": "Basic"
  },

...

}

Update PUT on AI Project

{
  "id": "/subscriptions/00000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.MachineLearningServices/workspaces/acctestaip-241128132257385881",
  "identity": {
    "type": "SystemAssigned",
    "userAssignedIdentities": null
  },
  "kind": "Project",
  "location": "westeurope",
  "name": "acctestaip-241128132257385881",
  "properties": {
    "description": "AI Project updated by Terraform",
    "discoveryUrl": "https://westeurope.api.azureml.ms/discovery",
    "enableDataIsolation": true,
    "friendlyName": "AI Project for OS models",
    "hbiWorkspace": false,
    "hubResourceId": "/subscriptions/00000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.MachineLearningServices/workspaces/acctestaihub-241128132257385881",
    "imageBuildCompute": "projectbuildupdate",
    "mlFlowTrackingUri": "azureml://westeurope.api.azureml.ms/mlflow/v1.0/subscriptions/00000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.MachineLearningServices/workspaces/acctestaip-241128132257385881",
   
 ...

  },
  "sku": {
    "name": "Basic",
    "tier": "Basic"
  },
  "tags": {
    "env": "test",
    "model": "regression"
  },
  "type": "Microsoft.MachineLearningServices/workspaces"
}

GET on parent AI Hub after Project was updated

{
  "id": "/subscriptions/00000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.MachineLearningServices/workspaces/acctestaihub-241128132257385881",
  "name": "acctestaihub-241128132257385881",
  "type": "Microsoft.MachineLearningServices/workspaces",
  "location": "westeurope",
  "tags": {
    "env": "test"
  },
  "etag": null,
  "properties": {
    "friendlyName": "AI Hub",
    "description": "AI Hub created by Terraform",
    "storageAccount": "/subscriptions/00000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.Storage/storageAccounts/acctestsa9tcd0",
    "keyVault": "/subscriptions/00000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.KeyVault/vaults/acctestvault9tcd0",
    "applicationInsights": null, <----- *** This suddenly begins returning null ***
    "hbiWorkspace": true,
    "tenantId": "00000",
    "imageBuildCompute": "buildtest",
    "provisioningState": "Succeeded",

...

        "associatedWorkspaces": [
      "/subscriptions/00000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.MachineLearningServices/workspaces/acctestaip-241128132257385881"
    ],
    "workspaceHubConfig": {
      "defaultWorkspaceResourceGroup": "/subscriptions/00000/resourceGroups/acctestRG-aiservices-241128132257385881"
    },
    "enableDataIsolation": true
  },
  "identity": {
    "type": "UserAssigned",
    "principalId": null,
    "tenantId": "00000",
    "userAssignedIdentities": {
      "/subscriptions/00000/resourceGroups/acctestRG-aiservices-241128132257385881/providers/Microsoft.ManagedIdentity/userAssignedIdentities/acctestuai-241128132257385881": {
        "principalId": "00000",
        "clientId": "00000"
      }
    }
  },
  "kind": "Hub",
  "sku": {
    "name": "Basic",
    "tier": "Basic"
  },

...

}

Expected behavior

Would expect the Application Insights ID of the Hub to be returned.

Actual behavior

The Application Insights ID is returned as null.

Reproduction Steps

The reproduction steps are described in the description above.

Environment

No response

[v-jiaodi]

@ZhidaLiu Please help take a look, thanks.