kgrid-python-runtime

KGrid Python Runtime

A KGrid runtime for Knowledge Objects in a native python environment that connects to an activator using the proxy adapter.

Prerequisites:

Installation from the python package:

Installation from an image:

This starts the runtime pointed to an activator running on the same system at localhost:8080

Endpoints

The runtime exposes two endpoints which can be used to see the details of the runtime and what has been activated

GET /info

Displays details about the runtime such as the running version and status.

GET /endpoints

Displays a list of the activated endpoints in the engine.

Configuration:

Set these environment variables to customize your runtime’s settings.

KGRID_PYTHON_ENV_URL

KGRID_PYTHON_ENV_PORT

KGRID_PROXY_ADAPTER_URL

KGRID_PYTHON_CACHE_STRATEGY

KGRID_PROXY_HEARTBEAT_INTERVAL

DEBUG

Creating a python Knowledge Object:

Just like other knowledge objects, python objects have 4 basic parts: service.yaml, deployment.yaml, metadata.txt, and a payload that can be any number of python files.

The packaging spec for knowledge objects can be found here.

An example KO with naan of hello, a name of neighbor, api version of 1.0, and endpoint welcome, a Deployment Specification might look like this:

/welcome:
  post:
    artifact:
      - "src/hello.js"
    engine: "python"
    function: "main"
    entry: "src/hello.js"
    

Where function is the name of the main javascript entry function.

You would then execute this endpoint to see the code work:

POST <activator url>/<naan>/<name>/<api version>/<endpoint>

In this example: POST <activator url>/hello/neighbor/1.0/welcome

The Service Specification for this object would likewise then be

openapi: 3.0.2
info:
  version: '1.0'
  title: 'Hello neighbor'
  description: An example of simple Knowledge Object
  license:
    name: GNU General Public License v3 (GPL-3)
    url: >-
      https://tldrlegal.com/license/gnu-general-public-license-v3-(gpl-3)#fulltext
  contact:
    name: KGrid Team
    email: kgrid-developers@umich.edu
    url: 'http://kgrid.org'
servers:
  - url: /js/neighbor
    description: Hello world
tags:
  - name: KO Endpoints
    description: Hello world Endpoints
paths:
  /welcome:
    post:
      ... 

In the Service Specification the servers.url must match the naan and name of the object (/js/neighbor) and the path must match the path in Deployment Specification (/welcome). The service spec conforms to the swagger OpenAPI spec.

If your python package requires other python packages, simply specify them in a file called requirements.txt at the root of your object:

package-name=0.1.5
other-package-name=1.3.5
third-package-name=1.5.4

Right now the python runtime only supports requirements.txt using pip, see the requirements.txt documentation.

That’s it! as long as the payload is written in valid python, and the object is built to the spec, you’re ready to go. Example python objects can be found in the example collection or in the example-objects directory in this repository.

For Developers

To run the app:

Clone this project and set the environment variable: PYTHONPATH to the project root.

Example (Ubuntu): export PYTHONPATH=~/Projects/kgrid-python-runtime

Run python kgrid_python_runtime/app.py runserver from the top level of the project.

Important Notes