Update Hiera by Python web service

Question

I currently have a setup of a puppet master and 2 agents. The requirement is to be able to deploy a simple web-app on the tomcats of both the agents, as and when required, based on request received from a REST web service.

Following are the steps:

1. User invokes REST service on Orchestration Layer with information like web-app path, nexus path etc.
2. Request comes to the Python based Orchestration Layer.
3. Orchestration Layer updates Hiera with the information passed in Step 1.
4. The web-app gets deployed on the agents.

Now I have certain questions:

1. Does this architecture looks feasible or is something has been missed ?
2. Which Python web framework would be best suited for the Orchestration Layer - Django, Flask, web.py or something else ?

Please advise.