While creating new Azure Function App in what scenario do I select operating system other than Windows?

Question

We created and tested several Azure Function Apps hosted at Windows. While creating new Azure Function App in what scenario do I select OS other than Windows? Meaning Linux or Docker.

I created test instances for all three OS selection options and basic settings of each of them appear to be very close.

Answer 1

Linux or Docker is useful if your functions have dependencies that only work on Linux/Docker. For example, some node.js native libraries only work on Linux, and will never work on Windows.

If you don't need Linux for anything specific, then I suggest sticking to Windows since that is currently (at the time of writing) the best and most supported environment for running Azure Functions.

Answer 2

Azure Functions 2.0 runtime is based on .NET Core, so it is cross-platform. If you choose Linux/Docker, Functions runtime will be deployed on Linux.

2.0 is still in preview, so Linux/Docker are not supported in production yet. For now, Consumption Plan (pay per call) is not supported.

See The Azure Functions on Linux Preview. Quote:

Functions on Linux can be hosted in a dedicated App Service tier in 2 different modes:

• You bring the Function App code and we provide and manage the container, no specific Docker related knowledge required.
• You bring your own Docker container including the Azure Functions runtime 2.0, specific dependencies, and Function App code.