Aether Python Library

This is the official Python Library with Aether functions.

Table of contents

• Requirements
• Installation
• Distribution
• Tests
• Usage
  • Redis tools

Requirements

This library requires Python 3.6 and above.

Python libraries:

• eha-jsonpath Provides new Extensions to the jsonpath_ng python library to provide commonly requested functions.
• jsonschema An implementation of JSON Schema validation for Python.
• redis Python client for Redis key-value store.
• requests HTTP for Humans.
• spavro An Avro library, Spavro is a (sp)eedier avro implementation using Cython.

Extra dependencies (based on settings):

• test
  • birdisle A modified version of redis that runs as a library inside another process.
  • coverage A tool for measuring code coverage of Python programs.
  • flake8 Tool For Style Guide Enforcement.
  • flake8-quotes Flake8 extension for checking quotes in python.
  • tblib Traceback serialization library.

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Installation

# standalone
pip3 install aether.python

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Distribution

How to create the package distribution

Execute the following command:

python3 setup.py bdist_wheel

or

./scripts/build.sh

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Tests

Depending on your preference you can either use virtualenv or pipenv to test the library locally.

Virtual Env

First install dependencies (execute it only once):

./scripts/install.sh

After that execute the following command:

source ./venv/bin/activate
./scripts/test.sh

Pipenv

In the root folder run:

pipenv install .

Then to test run:

pipenv run scripts/test.sh

The file scripts/test.ini contains the environment variables used in the tests.

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Usage

Redis Tools

This provides an interface to a Redis server via supplied redis parameters.

It makes available a number of CRUD redis operation which include but not limited to: - Formats document keys into _{type}:{tenant}:{id} before being cached on redis. - Retrieves documents based on preformated keys. - Removes documents based on preformated keys. - Subscribes to key based channels with a callback function.

Usage

from aether.python.redis.task import TaskHelper

REDIS_TASK = TaskHelper(settings, redis_instance)

# Settings must have the following properties:
# REDIS_HOST str - Redis server host,
# REDIS_PORT int - Redis server port,
# REDIS_PASSWORD str - Redis server password,
# REDIS_DB str - Redis database name

# redis_instance (Optional) - Pass an existing redis connection
# (If provided, ignores all settings and uses redis_instance)

document = {
    'id': 'document_id',
    'name': 'document name'
}

document_type = 'test_document'
aether_tenant = 'prod'

# add document to redis
REDIS_TASK.add(task=document, type=document_type, tenant=aether_tenant)

# retrieve document from redis
REDIS_TASK.get(_id=document['id'], type=document_type, tenant=aether_tenant)

# subcribe to a key based channel

CHANNEL = '_test_document*' # listens for messages published to all channels starting with '_test_document'

def handle_callback(msg):
    print(msg) # handle returned message

REDIS_TASK.subscribe(callback=handle_callback, pattern=CHANNEL, keep_alive=True)


# publish document
REDIS_TASK.publish(task=document, type=document_type, tenant=aether_tenant) # this will trigger the 'handle_callback' function with the published document to all subscribed clients