Making an existing code location components-compatible

note

This guide is only relevant if you are starting from an existing Dagster code location. This setup is unnecessary if you used dg code-location generate to create your code location.

Create a components directory

First, you'll want to create a directory to contain any new components you add to your code location. By convention, this directory is named components, and exists at the top level of your code location's Python module.

mkdir components

Modify top-level definitions

dagster-components provides a utility to create a Definitions object from your components directory. Because you're working with an existing code location, you'll want to combine your existing definitions with the ones from your components directory.

To do so, you'll need to modify your definitions.py file, or whichever file contains your top-level Definitions object.

You can manually construct a set of definitions for your components using build_component_defs, then merge them with your existing definitions using Definitions.merge. You point build_components_defs at the directory you just created that contains components.

Before

import dagster as dg

defs = dg.Definitions(assets=[])

After

from pathlib import Path

import dagster_components as dg_components

import dagster as dg

defs = dg.Definitions.merge(
    dg.Definitions(assets=[]),
    dg_components.build_component_defs(Path(__file__).parent / "components"),
)

Next steps

• Add a new component to your code location
• Create a new component type