Community involvement

Goals

In order to increase the level of community involvement in the OpenverseOpenverse Openverse is a search engine for openly-licensed media, including photos, audio, and video. Openverse is also the name for the collection of related code repositories that make up the project. Catalog code base, we have identified the following broad goals:

  • Make it as easy as possible to begin contributing code.
    • Maintain a codebase with obvious entrypoints where developers can jump in and contribute with as little initial overhead as possible. Ideally, only knowledge of basic python should be necessary.
    • Maintain a clean, readable codebase.
    • Maintain a codebase that conforms to PEP8
  • Be able to merge contributor pull requests safely, and put them into production quickly, allowing contributors to see the results of their efforts in the real world.
    • Increase the safety / testability of the Openverse Catalog code base
    • Automate more of deployment
  • Increase the visibility of Openverse Catalog as an avenue to contribute to the Search project.
    • Publicly document the areas of the code that are most amenable to contribution.
    • Advertise the desire for more contribution in Openverse Catalog.

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Action Plan

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Entrypoint to contribution

We have decided that one of the best places to jump into a contribution to the Openverse Catalog is to create a new script that pulls data from some previously unknown (to Openverse) APIAPI An API or Application Programming Interface is a software intermediary that allows programs to interact with each other and share data in limited, clearly defined ways. or modify one that already exists, adding new information. In this document, we will refer to such a script as a Provider API Script. Enabling such contributions, and advertising our hope for contribution in that area will be the focus of the remainder of this document.

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Technical changes making contribution easier

It seems like the number one way to make it less of a technical burden to contribute or modify a new Provider API Script is to make a clearer distinction between the code which is ‘generic’, i.e., used (in some form) by all Provider API Scripts, and that which is specific to the API of a particular provider.

Conceptually, the only thing the Provider API Script should need to know is about the Provider API itself, i.e., the

  • request format(s) necessary to get information
  • any authentication information — require this to be settable as an environment variable for now.
  • mapping from responses to different pieces of required information

From the perspective of the Provider API Script, the ‘pieces of required information’ are required arguments to a public function provided by the generic section of the code base, which adds information specific to a single image (perhaps something like add_image_info). Additionally, a Provider API Script should implement a specific ‘interface’ (used non-technically here) specified by Openverse that we can call from other parts of our infrastructure, e.g., Airflow. Once it has gathered the required info for a single image, the Provider API Script should simply call add_image_info from the generic part of the code base with the required information as arguments. The Provider API Script should call some commit method from the generic portion of the codebase before it exits, signaling that all is well, and the loaded images should be retained on disk for further processing.

The Generic Section of the codebase should provide a class (inspired by a Repository model, but slightly different/simplified) with a public method that takes the desired pieces of information as arguments. This method should be well-documented (both in its docstring and in the README somehow). In particular, the required types, and which arguments are required should be obvious. The following steps should be performed in the generic section of the codebase after this function is called:

  1. Validate the input for types
  2. Add required generic info based on input e.g.,
    • derive license from license URLURL A specific web address of a website or web page on the Internet, such as a website’s URL www.wordpress.org
    • derive version from license
    • derive source from provider
    • fill in watermarked false by default
  3. Add the .tsv row representing the image to some temporary .tsv file.

The Generic Section of the code base should provide a config.py to store information such as provider name strings.

The Generic Section of the code base should provide a way to define an Airflow DAG that knows how to call the main function of a properly-written Provider API Script.

Following are a series of steps (to be made into GithubGitHub GitHub is a website that offers online implementation of git repositories that can easily be shared, copied and modified by other developers. Public repositories are free to host, private repositories require a paid subscription. GitHub introduced the concept of the ‘pull request’ where code changes done in branches by contributors can be reviewed and discussed before being merged be the repository owner. https://github.com/ issues) that should move us in the direction outlined in this section.

  1. Write a class that can be imported into a Provider API Script, and which provides the model and functionality above, i.e.,:
    • Expose a public add_image_info (or some other name) function that lets the script add an image to an instance of the class.
    • Handle the verification of the given image data.
    • Log ‘generic’ things such as how many images have been imported in the current run
    • Expose a commit (or some other name) function that performs any broader validation, and moves temporary .tsv files to a permanent location to be picked up by the loaderWorkflow.py DAG.
    • All common logic involved with processing image data should live in, or be accessed through this class, and preferably through the add_image_info function.
    • It would be nice if this class (or one of its imports) handled formatting meta_data dictionaries, tags lists, and could derive license_ / license_version fields from a license_url.
    • Some of the functionality of etlMods.py should be reused.
  2. Write a module with other functionality that is generic:
    • Other functionality from etlMods.py should be preserved, e.g., requestContent.
  3. Rewrite wikimediaCommons.py into wikimedia_commons.py to serve as an example of how to use this class (this script makes sense because it needs rewriting to work around a current bug anyway).
    • Ensure that all generic functionality is extracted from wikimedia_commons.py, and lives in the ‘generic’ section of the codebase.

Once these steps are complete, we should have a working example of the desired model for Provider API Scripts, and their interaction with the generic portion of the codebase.

We should, if we like what we see after these changes, continue by rewriting all current Provider API Scripts in the new way. This will serve as a test of the new paradigm, and provide more examples for potential contributors to look at when designing and writing their own script.

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Technical changes making deployment of new Provider API Scripts safe and easy

As stated above, it would be nice if when a contributor has submitted their pull request, we have the technical capability to quickly and safely get their changes into production (should we so desire).

For this to be feasible, we need a considerably more robust test suite than currently exists. For example, there is currently a simple, probably correct Pull Request languishing in limbo because it is a modification of a public function used and potentially overridden in a number of other places in the code base, and there are no tests to help us know if the modification is having some unintended breaking effect somewhere else. Any section of the code that is intended to interface with contributor-provided scripts or other code, must be reasonably well tested, so that we can merge and deployDeploy Launching code from a local development environment to the production web server, so that it's available to visitors. with confidence. The sections of the code most relevant to Provider API Scripts should be tackled first in this matter.

  1. We should write a comprehensive test suite for etlMods.py. This module is used by every Provider API Script, and much of the functionality is untested.
  2. We should be fastidious in our own testing practices whenever rewriting any Provider API Script, as an example of what we expect for testing.
  3. We should make sure that public methods intended to be used by the Provider API Scripts are robust, well-tested, and give meaningful errors when called incorrectly.

As for deployment itself, we need to have a deployment set up that lets us both

  • put new code into production quickly and safely
  • test it in a realistic environment where applicable
  • roll back to a previous state if things go poorly.

For now, It should be possible to simply git pull from the running ec2, and the necessary pieces to run the Airflow DAGs, and their dependencies should all end up in the correct places. This implies:

  1. Restructuring the repo, and potentially splitting it into two pieces, to match the directory structure needed in prod.
  2. Split all dags into smaller pieces, so that they can be modified without affecting other workflows.

Eventually, it’d be nice to set up an automated deployment process that handles testing, and deployment to AWS after a git push has occurred (or something merged into the master branch).

  • We definitely need to split the repo before we’re ready for that stage.

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