Provenance

A common architecture used for data collection.

Provenance collects and stores articles from infoq.com and follows a Netflix Conductor-esque architecture.

History

In 2016 we began a project to address some of the concerns around fake news. While most were analyzing articles, we decided to take another approach; showing consumers where their content comes from. Our goal was to bring source [journalist] context to the foreground.

The exercise

Get the tests to pass!

• Query the articles gateway.
• Map rss results to a collection.
• Start the background worker.

Look for todo items in the codebase for where to get started.

Quick start

Download the codebase.

Create a jar file without running tests.

./gradlew assemble

Articles

Run the articles component tests to see what's failing.

./gradlew :components:articles:test

Review the todo comments in the ArticlesController class and get the tests to pass. Along the way it will be helpful to use the writeJsonBody method to convert articles to json.

writeJsonBody(servletResponse, articles);

Endpoints

Run the endpoints component tests to see what's failing.

./gradlew :components:endpoints:test  

Review the todo comments in the EndpointWorker class and get the tests to pass. Along the way it will be helpful to use XmlMapper to convert RSS feeds to Java objects.

RSS rss = new XmlMapper().readValue(response, RSS.class);

Test suite

Ensure all the tests pass.

./gradlew build

Schedule work

Review todo comments in the App class within the provenance-server component. Create and start a WorkScheduler.

WorkScheduler<EndpointTask> scheduler = new WorkScheduler<>(finder, workers, 300);

Pro tip: review the testScheduler test in the WorkSchedulerTest class.

Run locally

Build the application again then run it locally to ensure that the endpoint worker is collecting articles.

./gradlew build
java -jar applications/provenance-server/build/libs/provenance-server-1.0-SNAPSHOT.jar 

Make a request for all articles in another terminal window.

curl -H "Accept: application/json" http://localhost:8881/articles

Hope you enjoy the exercise!

Thanks,

The IC Team

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