EO Application Packages in 20 minutes

A short introduction to Earth Observation Application Packages (EOAP), using CWL v1.2 and a raster-bounds example. Students learn how job inputs, a workflow, a container command and output files fit together.

Start with the documentation or lesson source. The 20-minute route needs no installation: three minutes of context, four minutes on the building blocks, eight minutes tracing the example, three minutes on deployment, and a two-minute knowledge check.

The 2026 perspective includes ESA adoption through the EOEPCA initiative and EOEPCA+, with sources linked in the lesson. Historical OGC testbeds remain available as optional background. The three notebooks are longer, optional practical labs.

Build the documentation

python -m pip install mkdocs-material mkdocs-mermaid2-plugin
mkdocs serve
# Check links and configuration:
mkdocs build --strict

The site includes the current job-file example directly from notebooks/inputs.yaml.

Typed CWL and PDE validation

The notebook environment targets Python 3.12. requirements-notebooks.in records the PDE's direct dependencies; requirements-notebooks.txt locks all resolved packages and their hashes. Podman remains a system dependency.

Install the environment and register both notebook kernels:

uv venv --python 3.12 .venv
uv pip sync --python .venv/bin/python --require-hashes requirements-notebooks.txt
.venv/bin/python -m ipykernel install --user --name cwl_env --display-name "Python (cwl-eoap)"
.venv/bin/python -m bash_kernel.install
source .venv/bin/activate

Refresh the lock deliberately, then execute all three notebooks before accepting the new versions:

uv pip compile requirements-notebooks.in --python-version 3.12 --generate-hashes --upgrade --output-file requirements-notebooks.txt

The sibling PDE's cwl-eoap/files/init.sh uses Python 3.12 and installs this lock with uv pip sync --require-hashes, retaining its kernel registration and PATH setup. Publish the lock with the training source or copy it into the PDE workspace before deploying the updated initialization script.

Application packages use CWL v1.2, shared remote URI schemas, described ports and Schema.org repository/version/license/author metadata. Generate and validate standalone documentation with python scripts/cwl-docs.py --validate. The PDE deployment and executable lab tasks are in the sibling dev-platform-eoap/cwl-eoap folder. Feature-branch changes must be published or copied into its retained workspace before deployment.

All three notebooks passed on AMD64 Kubernetes on 11 October 2026. The Python lab asserts successful CLI execution and a raster result; container labs use the current user's UID/GID, and the package lab exercises typed URI job files. The rasterio container installs its required native libexpat library.

Release acceptance

The Notebook acceptance workflow installs the hash-locked Python 3.12 notebook environment and Podman, validates the standalone CWL and generated Markdown, executes all three notebooks with real EO inputs, and builds the site strictly. Executed notebooks and documentation are retained as CI artifacts. Run the same notebooks locally with:

source .venv/bin/activate
python scripts/run-notebooks.py --workspace "$PWD" --notebooks-dir notebooks --python-kernel cwl_env --output /tmp/cwl-eoap-acceptance

Notebook cells deliberately generate files and build local teaching containers. Start acceptance from a clean checkout of the intended release commit. Release promotion requires successful acceptance of that commit; the CWL currently identifies the module version as 1.0.0.