dbt-fusion-package-tools 0.20.0a1

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Package Management

This directory contains code used by the packages option in the CLI that upgrades packages in a project to a Fusion-compatible version. The code is centered on four classes:

• DbtPackageFile: represents a file (currently packages.yml or dependencies.yml) that contains package dependencies for a project
• DbtPackage: represents a package that is installed as a dependency for the project
• DbtPackageVersion: represents a specific version of a package
• DbtPackageTextFile: contains the raw lines of text from package dependency files. This is used when upgrading packages so we can replace just the version strings within a file without affecting the rest of the file layout (such as comments).

How the CLI works

The packages command calls the upgrade_packages function in main.py. This then calls:

• generate_package_dependencies: extracts dependencies from project's packages.yml/dependencies.yml file and identifies installed package versions in dbt_packages
  • Returns DbtPackageFile if a packages.yml/dependencies.yml file is found and specifies at least one package; otherwise, None
• check_for_package_upgrades: traverses the dependencies in DbtPackageFile and for each package, determines if the current installed versions is Fusion compatible; if not, it looks for any Fusion-compatible versions of the package
  • Returns list of PackageVersionUpgradeResult
    • Length should exactly match the number of packages in the DbtPackageFile's dependencies
• upgrade_package_versions: takes the PackageVersionUpgradeResult list and if any packages need updates, it identifies the required changes in packages.yml. For a dry run, it prints out the new packages.yml; otherwise, it actually makes the changes in the file.
  • Returns a single PackageUpgradeResult
• print_to_console on the PackageUpgradeResult

upgrade_packages will generate an error if:

• the path specified in --path does not exist or isn't a directory
• generate_package_dependencies can't find a packages.yml or dependencies.yml
• generate_package_dependencies found a packages.yml or dependencies.yml but it didn't contain any package dependencies

Scripts

• Used to extract info used in package upgrade CLI:
  • get_package_hub_files.py: download package information from package hub (hub.getdbt.com) for all versions of all packages
    • Output: package_output.json
  • get_fusion_compatible_versions.py: loads package_output.json and summarizes Fusion compatibility across all versions for each package
    • Output: fusion_version_compatibility_output.json and fusion_version_compatibility_output.py
• Not used as an input to the package upgrade CLI:
  • packages_with_fusion_compatibility_changes.py: reads fusion_version_compatibility_output.py and generates a CSV summary of packages for analytics use
    • Output: packages.csv

get_package_hub_files.py and get_fusion_compatible_version.py are used to pull data from the public package registry (hub.getdbt.com) and extract Fusion compatibility information from available versions. This is basically a local cache of package information to bootstrap autofix. We need to know the lower bound of Fusion-compatible versions for a package but we also know that older versions of packages will not change, so caching this locally removes a lot of repetitive network calls and text parsing. Which means faster run times and fewer failures due to network issues.

The output from these two scripts produces fusion_version_compatibility_output.py that contains a single constant, FUSION_VERSION_COMPATIBILITY_OUTPUT. This is then used in DbtPackage's merge_fusion_compatibility_output to populate compatible versions.

TODO

• Private packages
  • Check require_dbt_version in installed private packages
  • Need a way to match the dependency in packages.yml (since it doesn't have the name which is used for public packages)
• Match the version specifier type when upgrading packages
  • Currently if the package config specifies a version like ">1.0.1" and we need to upgrade to 1.0.2, it gets replaced with "1.0.2"
  • Should instead replace with same format like ">1.0.2"
• Get latest versions from package hub instead of using cache
• Better handling for version in package's dbt_project.yml
  • Sometimes the version number in the package's dbt_project.yml doesn't actually match the release version because package hub only checks the release tag on Github, so the installed version check will set an incorrect version
  • Added logic in DbtPackageFile will override the installed version if it's less than the config's version range, but this isn't 100% reliable
  • Could instead refer to the package lock file to find the exact version
  • But probably not a huge problem since we are only looking for the require dbt version anyway and only look for upgrades if it's missing/incompatible
• Move package parsing logic to hubcap or package hub where appropriate
• Explicit overrides at version level
  • Currently in scripts/get_fusion_compatible_versions and DbtPackageVersion.is_version_explicitly_disallowed_on_fusion, but should refine logic