How to deploy ASP.NET Core with COM module dependencies on Azure

Question

Hello! 

We are trying to deploy an ASP.NET Core, .NET 8.0. Web Service to Azure. However, we have trouble registering the COM modules for the deployment process.

What we’ve tried:

• Initially, we tried to deploy the service by publishing it to Azure as an App Service through Visual Code. (Reference: https://learn.microsoft.com/en-us/azure/app-service/quickstart-dotnetcore) However, we didn't find a way to register the COM modules. So they are missing when running the deployed app, leading to an error. 
• Next, we tried to build the service in a Docker container. However, it appears we cannot use Docker with a .NET Core project that has COM references. (We get this error: The task "ResolveComReference" is not supported on the .NET Core version of MSBuild. Please use the .NET Framework version of MSBuild.)

We asked and researched around and found the following other options:

• “Switch from .NET Core to .NET Framework to allow referencing COM modules”
• “Deploy ASP.NET Core to IIS on Windows servers”
• “Use Registration-Free COM Interop” 

However, we are missing a lot of context around these alternatives and are not sure where to go next. Frankly, we are a team that has not worked within this ecosystem and we are a bit lost. Any help would be much appreciated.

Answer 1

You can get started with a Windows Server virtual machine on Azure, which is the closest to what you previously used to develop/host such COM based bits.

However, whether you can migrate to more modern options, such as Windows containers, is subject to the COM bits themselves (and their vendors if you still have contacts). I won't suggest you try that out all by yourself, as very likely you will hit different kinds of migration issues.

Answer 2

You should be using a windows container. Your com objects should already have an installer which you should run on the container build. If you don’t have one, you could use a .net 4.8 project for the com objects install and create an installer that you run before the .net install.