Microsoft Azure Java Function Packaging Deploy Notes

It appears that this boils down to creation of a zip file of a similar format to (and deployed via the methods specified) here

The files (host and function.json) have references in this area of documentation: https://docs.microsoft.com/en-us/azure/azure-functions/functions-host-json

It appears the zip is an empty host.json at the top (along with project jar dependencies - external dependencies may go in a lib folder), and a folder for each function name containing a function.json file describing it (pending verification via maven example, as package at least appears to work)

General doc about that can be found here: https://docs.microsoft.com/en-us/azure/azure-functions/functions-reference-java

Original Notes

Notes on an attempt to reverse engineer the build-system agnostic steps necessary to build and deploy a Java function to Azure. I started from the current maven plug-ins

Packaging

The current maven plug-ins first use reflection to find annotated function entry points and parse a configuration from them. After that, they assemble some JSON files and classes into a staging directory as part of the package step. All noted locations are relative to the specific build sub-directory created by the plug-ins for staging.

Annotation-Based Values

Stored in a map, keyed with a detected function's FunctionName annotation value

FunctionConfiguration

entryPoint: canonical-class-name.method-name

TODO Bindings

There are a WHOLE bunch of binding annotations it detects and creates slightly-customized JSON for the parameters

Parameter bindings: com.microsoft.azure.maven.function.bindings.BindingFactory

Same for return type bindings, but if it finds an HttpTrigger param annotation on a non-void return and no other method-level bindings, it adds an HttpBinding

Finally, if there is a StorageAccount method binding, it applies its values as the connection for any StorageBaseBinding instances with a blank connection

host.json

Written as an empty json file

{}

{functionName}/function.json

Describes a single function, and written from the reflection-based data read earlier in the packaging process

TODO structure

Jars

All jars in the build directory appear to copied to the root of the staging directory

Deploy

Deployment type: zip

Create or update function app:

TODO