README.md

Apache Beam Simple OGDC Recipe Exploration

This repository has been archived.

This repo was an exploration of using Apache Beam to create a simple OGDC recipe. The QGreenland-Net team is no longer considering the use of Apache Beam, and instead is pursuing the use of Argo Workflows. See the ogdc-runner for the latest developments.

The point of this spike is to show an example of a very simple representation that works for a very constrained use case. This makes some chunk of use cases much more accessible, similar to what repo2docker does for managing Docker image builds. Anything beyond the simplest string of shell commands should be a custom recipe.

The current program emits:

recipe = (
  beam.io.SomeTransformThatCanReadAFileFromAUrl(https://example.com/something)
  | CommandPTransform("""gdalwarp -t_srs EPSG:3413 {input} {output}""")
  | CommandPTransform("""echo "Heya!"""")
)

Thoughts

• The list of commands could be represented as a PCollection that is handled by a PTransform that generates "sub-PTransforms" (.expand() method on a PTransform class?)? Could that help us skip the step of generating a Python executable and instead pass that raw PCollection data to a static recipe.