_{Photo by Fran Jacquier on Unsplash}

The Issue

I need to generate OLE stream from File to embed them in a Word document. It seems easy using native DLL. But they are only present on Windows with desktop experience.

I tried to find a cheap way to run it in Azure, but:

• Azure Web App for Container, is too expensive when it comes to host Windows container
• Azure Function with custom image, require a Premium Plan, which is too expensive
• Azure Container Instance (ACI), seems good

Find the right image, for the right job

Ok, to deploy quickly on ACI, we need to have the tiniest possible image.
So we have to select carefully the image we put the code on.
ACI can support

• nanoserver
• windows server core
• windows

Obviously both nanoserver and windows server core do not have Windows experience.

So let's try a 2004 image of a Windows Server (see the list of tag supported).

Azure respond with the following error : Error OsVersionNotSupported .

The Error

The error specify that the image is not supported.
Weird.
But, in fact ACI supports the Long Term Support version of Windows Server, no images based on Semi Annual Channel.

It means, that 2004, or 1909 images are not supported, but 1809 is.
It works, but the image is huge and takes 20 minutes at least to be deployed on a 1 CPU / 1 Go Memory container.

Hope this helps !