palm-dbt 0.0.4

dbt extension for Palm CLI

Palm dbt

dbt plugin for Palm CLI

This plugin adds dbt-specific commands for use with Palm CLI

Installing

Install this plugin along with palm

pip install palm-dbt

Or from source

python3 -m pip install .

Configuring your project

To configure your project to use the palm-dbt plugin, you will need a .palm/config.yaml this can be created by running palm init, once you have your config file, add the dbt-palm plugin with the following configuration:

plugins:
  - dbt

Adding palm dbt macros

palm-dbt uses the git branch name to set the schema for all commands via env vars. This allows palm to clean up test data after each run, ensuring that your data warehouse stays clean and free of development/test data.

To enable this functionality, palm-dbt ships with 2 macros that handle schema naming and cleanup:

• generate_schema_name - This macro overrides the dbt-core macro to auto-generate a schema name based on your current git branch and PALM_DBT_ENV.

• drop_branch_schemas - This macro uses the branch named schema and the TEST database to clean up any models generated by running dbt in development or test environments. Calls to this macro are baked in to many of the palm dbt commands.

See the section about the palm dbt naming macros below for more information.

To install these macros, run palm install from within a project that is configured to use the palm-dbt plugin.

Recommended (optional) protected branch configuration

In order to ensure your runs are idempotent, we recommend that you do not run palm-dbt commands against main, master or any other production-like branches you may be using.

To prevent palm running against specific branches, add the following config to your project's .palm/config.yaml

protected_branches:
  - main
  - master
  # Any other branches you want to protect

About the palm dbt branch naming macros

One of the most painful parts of data testing is unfortunate shared mutable state. palm-dbt provides a mechanism to eliminate this undesirable situation by namespacing each run of dbt. for git branches other than main or master, palm will prefix the calculated schema name with a formatted version of your branch name. In CI, this will be additionally prefixed with "CI". For example:

• you open a branch FEATURE/DATA-100/update-widget
• when you palm run in your local env, the schema public will be built as feature_data_100_update_widget_public. The schema sales will be built as feature_data_100_update_widget_sales.
• in CI the schemas will be ci_feature_data_100_update_widget_public, ci_feature_data_100_update_widget_sales (respectively).
• in prod the schemas will be 'public' and 'sales' (respectively).

Refs will automatically update as well. This way, you can use a single test database and not worry about conflicts between developers, or between branches for the same developer (like during hotfixes).

Typical palm-dbt workflow

From a non-protected branch, running palm run will:

1. drop (if it exists) the namespaced schema in development
2. create the namespaced schema in development
3. clean, deps, seed and run
4. drop the namespaced schema in development

Why drop it? so your testing is atomic.

Want to persist it? use the flag --persist