Add Azure Function API

[odaibert]

[simonkurtz-MSFT]

Some ideas here:

• Host the Function App in a consumption plan with a Windows subsystem as Linux does not presently allow for editing functions in the code editor in the Azure Portal.
• Keep the function app simple: Two GET methods with and without parameters would illustrate the integration well. Lab participants know how REST APIs work and can extrapolate from this example how other HTTP Verbs such as PUT, POST, DELETE, etc. work.
• Running in consumption means no VNet integration. That's ok for the lab. I consider VNet integration and network security a higher-level construct. Do ensure that we highlight how APIM can interact with the Azure Function via the function key to prevent unauthorized callers.

[simonkurtz-MSFT]

@odaibert & @ferantoMSFT, what do you think about my ideas above, please?

[odaibert]

@simonkurtz-MSFT we have another APIM workshop with serverless focus. Maybe we can use the same function apps from it (that was the original idea).

You can find it here https://github.com/Azure-Samples/Serverless-APIs