announcement_client.md

Overview

Amundsen's announcement feature requires that developers create a custom implementation of announcement_client for collecting announcements. This feature provide ability to deliver to Users announcements of different sort regarding data discovery service.

Implementation

Implement the announcement_client to make a request to system storing announcements.

Shared Logic

announcement_client implements _get_posts() of base_announcement_client with the minimal logic for this use case.

It collects the posts from get_posts() method.

try:
    announcements = self.get_posts()
except Exception as e:
    message = 'Encountered exception getting posts: ' + str(e)
    return _create_error_response(message)

It verifies the shape of the data before returning it to the application. If the data does not match the AnnouncementsSchema, the request will fail.

# validate the returned object
data, errors = AnnouncementsSchema().dump(announcements)
if not errors:
    payload = jsonify({'posts': data.get('posts'), 'msg': 'Success'})
    return make_response(payload, HTTPStatus.OK)
else:
    message = 'Announcement data dump returned errors: ' + str(errors)
    return _create_error_response(message)

Custom Logic

announcement_client has an abstract method get_posts().

This method will contain whatever custom logic is needed to collect announcements. The system within which they are stored can be anything that has programmatic access.

Announcements could be collected from database (as in exemplary SQLAlchemyAnnouncementClient), kafka persistent topic, web rss feed, etc.

See the following example_announcement_client for an example implementation of base_announcement_client and get_posts(). This example assumes a temporary sqlite database with no security, authentication, persistence or authorization configured.

Usage

Under the [announcement_client] group, point the announcement_client entry point in your local setup.py to your custom class.

entry_points="""
    ...

    [announcement_client]
    announcement_client_class = amundsen_application.base.examples.example_announcement_client:SQLAlchemyAnnouncementClient
"""

What do I need to run exemplary announcement_client ?

Exemplary client requires installation of SQLAlchemy to run properly:

pip install SQLAlchemy==1.3.17

Run python3 setup.py install in your virtual environment and restart the application for the entry point changes to take effect