Amazon.Lambda.Tools does not seem to support Microsoft.NETCore.App 3.0

[l1x]

I get the following error when building with netcoreapp3.0:

dotnet lambda package --configuration release --framework netcoreapp3.0 --output-package bin/release/netcoreapp3.0/deploy-package.zip
It was not possible to find any compatible framework version
The specified framework 'Microsoft.NETCore.App', version '2.1.0' was not found.
  - The following frameworks were found:
      3.0.1 at [/usr/local/share/dotnet/shared/Microsoft.NETCore.App]

You can resolve the problem by installing the specified framework and/or SDK.

The .NET Core frameworks can be found at:
  - https://aka.ms/dotnet-download

Is this expected?

[klaytaybai]

Hi @l1x. I don't think this error is expected. Reading dotnet/core#3487 might help you out.

You can read more about working with .NET Core 3.0 in Lambda here.

[l1x]

Thanks. I think 3.1 is a LTS and it is going to be supported as a runtime. I am going to wait for that.

[scionwest]

Hi @l1x and @klaytaybai - I have a repository that you can use as reference for deploying a .Dotnet Core 3.0 Runtime into Lambda using the AWS extensions for the Dotnet CLI.

The repository is here. There is a file called Program.cs where I instantiate an instance of Lambda entry class. My Lambda entry is wrapped by an Amazon HandlerWrapper and LambdaBootstrap instance. You just need to add the Amazon.Lambda.RuntimeSupport NuGet package.

The repository can be cloned and ran as-is. You can deploy the Dotnet Core 3.0 runtime into your AWS environment, the Readme includes instructions to do so via the Lambda Dotnet CLI extension.

You can read more about how it works from the AWS blog post. You'll want to note the differences in the serverless.template file as the runtime is left blank due to the Lambda providing the runtime as part of the deployment.