Harmony Regridding Service

This repository contains the source code, unit test suite, Jupyter notebook documentation and build-related scripts for the Harmony Regridding Service. The initial version of this service will perform regridding only, for collections with one geographic grid to another geographic grid, in support of the GES DISC GPM/IMERGHH and MERRA collections.

Repository structure:

|- CHANGELOG.md
|- CONTRIBUTING.md
|- README.md
|- legacy-CHANGELOG.md
|- bin
|- docker
|- harmony_regridding_service
|- pip_requirements.txt
|- tests

• .snyk - A file used by the Snyk webhook to ensure the correct version of Python is used when installing the full dependency tree for the Harmony Regridding Service. This file should be updated when the version of Python is updated in the service Docker image.
• CHANGELOG.md - This file contains a record of changes applied to each new public release of a service Docker image. Any release of a new service version since migrating to GitHub should have a record of what was changed in this file (e.g., starting at version 1.0.0).
• CONTRIBUTING.md - General guidelines for making contributions to the repository.
• LICENSE - The NASA open-source license under which this software has been made available.
• README.md - This file, containing guidance on developing the service.
• legacy-CHANGELOG.md - This file contains release notes for all versions of the service that were released internally to EOSDIS, before migrating the service code and Docker image to GitHub.
• bin - A directory containing utility scripts to build the service and test images.
• docker - A directory containing the Dockerfiles for the service and test images. It also contains service_version.txt, which contains the semantic version number of the service image. Any time an update is made that should have an accompanying service image release, this file should be updated.
• docs - A directory containing Jupyter notebook documentation showing an end-user how to use the service.
• harmony_regridding_service - The directory containing Python source code for the Harmony Regridding Service. adapter.py contains the RegriddingServiceAdapter class that is invoked by calls to the service.
• pip_requirements.txt - A list of service Python package dependencies.
• tests - A directory containing the service unit test suite.

Contributing:

Contributions are welcome! For more information, see CONNTRIBUTING.md.

Python dependencies:

At this time, the service only requires dependencies that can be obtained via Pip. The service dependencies are contained in pip_requirements.txt. Additional test dependencies are listed in tests/pip_test_requirements.txt.

Local development:

Local testing of service functionality is best achieved via a local instance of Harmony. Please see instructions there regarding creation of a local Harmony instance.

If testing small functions locally that do not require inputs from the main Harmony application, it is recommended that you create a Python virtual environment via tools such as pyenv or conda, and install the necessary dependencies for the service within that environment via Pip.

Tests:

This service utilises the Python unittest package to perform unit tests on classes and functions in the service. After local development is complete, and test have been updated, they can be run via:

$ ./bin/build-image
$ ./bin/build-test
$ ./bin/run-test

The tests/run_tests.sh script will also generate a coverage report, rendered in HTML, and scan the code with pylint.

The unittest suite is run automatically via GitHub Actions as part of a GitHub "workflow". These workflows are defined in the .github/workflows directory.

pre-commit hooks:

This repository uses pre-commit to enable pre-commit checking the repository for some coding standard best practices. These include:

• Removing trailing whitespaces.
• Removing blank lines at the end of a file.
• JSON files have valid formats.
• ruff Python linting checks.
• black Python code formatting checks.

To enable these checks:

# Install pre-commit Python package as part of test requirements:
pip install -r tests/pip_test_requirements.txt

# Install the git hook scripts:
pre-commit install

# (Optional) Run against all files:
pre-commit run --all-files

When you try to make a new commit locally, pre-commit will automatically run. If any of the hooks detect non-compliance (e.g., trailing whitespace), that hook will state it failed, and also try to fix the issue. You will need to review and git add the changes before you can make a commit.

It is planned to implement additional hooks, possibly including tools such as mypy.

pre-commit.ci is configured such that these same hooks will be automatically run for every pull request.

Versioning:

Service Docker images for the Harmony Regridding Service adhere to semantic version numbers: major.minor.patch.

• Major increments: These are non-backwards compatible API changes.
• Minor increments: These are backwards compatible API changes.
• Patch increments: These updates do not affect the API to the service.

When publishing a new Docker image for the service, two files need to be updated:

• CHANGELOG.md - Notes should be added to capture the changes to the service.
• docker/service_version.txt - The semantic version number should be updated.

Docker image publication:

Service Docker images are published to ghcr.io any time a change is merged to the main branch that contains an update to docker/service_version.txt.

Releasing a new version of the service:

Once a new Docker image has been published with a new semantic version tag, that service version can be released to a Harmony environment by updating the main Harmony Bamboo deployment project. Find the environment you wish to release the service version to and update the associated environment variable to update the semantic version tag at the end of the full Docker image name.

Get in touch:

You can reach out to the maintainers of this repository via email:

• david.p.auty@nasa.gov
• owen.m.littlejohns@nasa.gov
• matthew.savoie@colorado.edu