azure-functions-core-tools: better error message if the CLI sees nested values in local.settings.json

The solution was to right-click on local.settings.json, go to properties, change “Copy to Output directory” from “Do not copy” to “Copy always”. Now the CLI picks up the settings when running from within Visual Studio 2017.

Got it! If you use settings with more than one level in local.settings.json, it ignores the whole “Values” section and gives you this error. Ex: This is OK:

 "Values": {
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
    "AzureWebJobsDashboard": "UseDevelopmentStorage=true",

    "Foo:Url": "http://localhost:3030",
    "Foo:Token": "token"
  }

But this generates an error:

 "Values": {
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
    "AzureWebJobsDashboard": "UseDevelopmentStorage=true",

    "Foo":  {
        "Url" : "http://localhost:3030",
        "Token": "token"
      }
  }

This needs to fail with a better error message. Why would anyone expect valid, legal JSON to cause problems? If you aren’t going to support nested JSON, then return an warning saying as much, highlighting which properties are in violation. Key-values that are the expected string/string should still just work fine.

@alemag1986 sorry for the delay.

This is because of this value

"MSNotificationHub": {
  "HubName": "<changed by alemag>",
  "ConnectionString": "<changed by alemag>"
}

Values collection is expected to be a Dictionary<string, string> and it’s failing to parse it and returning an empty dictionary. I think parsing it as a JObject and displaying an error for any non-string values would be more correct here.

I know it’s a bit confusing with the .NET Core appsettings.json, but this file local.settings.json is meant to just be a local equivalent to the Azure App Settings which are just key-value pairs.

You can test that locally by running func settings list in that directory. It should print empty values and connection strings. removing that MSNotificationHub property should get func settings list to work.

Since settings.json does not support nested JSON, can you please describe the recommended alternative to storing nested JSON in configuration?

for those who are not behind VS, the CopyToPublishDirectory is what did the trick in my environment:

Azure Functions Core Tools (2.0.1-beta.31) Function Runtime Version: 2.0.11888.0

<None Update="local.settings.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
      <CopyToPublishDirectory>PreserveNewest</CopyToPublishDirectory>
 </None>

with the following local.settings.json

{
    "IsEncrypted": false,
    "Values": {
        "AzureWebJobsStorage": "DefaultEndpointsProtocol=...",
        "AzureWebJobsDashboard": "",
        "FUNCTIONS_WORKER_RUNTIME": "dotnet"
    }
}

@alemag1986 sorry for the delay.

This is because of this value

"MSNotificationHub": {
  "HubName": "<changed by alemag>",
  "ConnectionString": "<changed by alemag>"
}

Values collection is expected to be a Dictionary<string, string> and it’s failing to parse it and returning an empty dictionary. I think parsing it as a JObject and displaying an error for any non-string values would be more correct here.

I know it’s a bit confusing with the .NET Core appsettings.json, but this file local.settings.json is meant to just be a local equivalent to the Azure App Settings which are just key-value pairs.

You can test that locally by running func settings list in that directory. It should print empty values and connection strings. removing that MSNotificationHub property should get func settings list to work.

@ahmelsayed I think this really needs some better warning on failure - I’ve just spent a lot of time trying to work out why my application settings weren’t being read, and I don’t think it’s unreasonable to assume that valid JSON, in the format recommended elsewhere by Microsoft for .NET Core app settings, silently continues without loading any settings.

Also found out that arrays are not supported

...
    "MonthlyIntervals": [3, 6, 12, 18, 24]
...