Microsoft.Azure.KeyVault (Microsoft.Azure.Services.AppAuthentication) issue on functions runtime 2.0.11651-alpha

[Bubeee]

Hi, I'm developing Azure Functions v2 in Visual Studio with latest tools installed. (.NET Core)

After an attempt to apply Azure KeyVault secrets to my functions (like described here https://medium.com/statuscode/getting-key-vault-secrets-in-azure-functions-37620fd20a0b) I've faced with issue on startup of function app in Azure. Kudu logs dump says the following:

Hosting environment: Production
Content root path: D:\Program Files (x86)\SiteExtensions\Functions\2.0.11651-alpha
Now listening on: http://localhost:12938
Warning: Only got partial types from assembly: MiddleWare.External.Functions, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null
Exception message: System.Reflection.ReflectionTypeLoadException: Unable to load one or more of the requested types. Retrieve the LoaderExceptions property for more information.
   at System.Reflection.RuntimeModule.GetTypes(RuntimeModule module)
   at System.Reflection.RuntimeModule.GetTypes()
   at System.Reflection.Assembly.GetTypes()
   at Microsoft.Azure.WebJobs.Host.Indexers.DefaultTypeLocator.FindTypes(Assembly assembly, IEnumerable`1 extensionAssemblies) in C:\projects\azure-webjobs-sdk-rqm4t\src\Microsoft.Azure.WebJobs.Host\Indexers\DefaultTypeLocator.cs:line 120

Investigative information

• Timestamp: 2018-05-14 15:31:55.862
• Function App version (1.0 or 2.0-beta): v2.0-beta
• Function App name:
• Function name(s) (as appropriate):
• Invocation ID:
• Region:

Repro steps

Provide the steps required to reproduce the problem:

Expected behavior

1. Azure Functions working, retrieving secrets from the Key Vault instance on demand, correctly authenticating in Azure AD.

Actual behavior

Azure functions not starting, manual triggering causes 400 error. Kudu log dump provided above.

Known workarounds

Implementing custom Token Provider like on the screen below resolves the issue.

So I think the issue is in the AppAuthentication package. I've debugged functions remotely in visual studio, but unfortunately it takes a lot of time to attach, and filter all not related exceptions during the debugging of actual issue with AzureServiceTokenProvider.

As soon as I got rid of the Microsoft.Azure.Services.AppAuthentication dependency, functions are able to start.

Now, switching to v1 version and will implement it there. So, not waiting for a quick answer, just want to recollect the thoughts and maybe I've missed something.

[Bubeee]

Migrated to Functions v1 and faced with the same issue.

2018-05-15T14:08:25 Welcome, you are now connected to log-streaming service. 2018-05-15T14:08:26.569 [Info] Function started (Id=10e4932a-705f-4879-bb00-db2a6857e3c7) 2018-05-15T14:08:26.585 [Info] C# Timer trigger function executed at: 5/15/2018 2:08:26 PM 2018-05-15T14:08:26.632 [Error] Function completed (Failure, Id=10e4932a-705f-4879-bb00-db2a6857e3c7, Duration=60ms)

After applying this code:

UPDATE: After some time it magically became working =\

[paulbatum]

What can you tell us about the assembly MiddleWare.External.Functions? This error message about partial types is not familiar. Is there something unusual about this assembly?

[Bubeee]

@paulbatum hi, If talking about the first attempt with Functions v2, it's casual Functions project.