Banshee

A CLI for managing large-scale code changes across a GitHub organisation, and the lifecycle of Pull Requests created.

Why

As any company grows, you accumulate small pieces of tech debt, particularly for products that use software built by infrastructure and platform teams.

For 50 engineers, it's acceptable to ask for a 10-line change. At 500 engineers, it's a lot less reasonable.

Hopefully this CLI helps manage those code changes and the pull request lifecycle required to get them applied.

Highlighted Features

• 🤖 Github App creds for higher ratelimits and impersonal attribution.
• 🚚 Progress saving which lets you stop, start and resume migrations any time, or in the event of an error.
• 🍞 Batching so you can space out the work over multiple days/weeks.
• ✅ Assign reviewers as a default if codeowners don't get assigned, never leave a PR unreviewed again
• 📋 View a list of PRs related to the migration, in any state

Install

export ARCH="darwin-arm64"
# export ARCH="darwin-amd64"
# export ARCH="linux-amd64"
curl -o banshee -L "https://github.com/TheJokersThief/Banshee/releases/latest/download/banshee-${ARCH}" \
  && chmod +x banshee \
  && sudo mv banshee /usr/local/bin/

Usage

Usage: banshee <command>

Flags:
  -h, --help                      Show context-sensitive help.
  -c, --config="./config.yaml"    Path to global CLI config

Commands:
  version
    Print banshee CLI version

  migrate <path>
    Run a migration

  list <path>
    List PRs associated with a migration
  
  merge <path>
    Merge PRs not blocked by any branch protections

  clone <path>
    Clone all of the repositories that are going to be involved in a migration

Run "main <command> --help" for more information on a command.

Examples

Pre-cloning repos for migration

banshee clone examples/migration_config/migration.yaml \
    --config examples/global_config/config.yaml \

Running a migration

banshee migrate examples/migration_config/migration.yaml \
    --config examples/global_config/config.yaml

Listing all PRs for a migration

banshee list examples/migration_config/migration.yaml \
    --config examples/global_config/config.yaml \
    --state all \
    --format json

Merging any PRs not blocked by branch protections

This assumes that you block merge to mainline branches with branch protections like "requires a PR", "required approvers: 1", "required status checks" and that they're not handled on the honour system.

This just checks the GitHub "mergeable state" is "clean" (terms determined by GitHub)
to see if the PR can be merged.

banshee merge examples/migration_config/migration.yaml \
    --config examples/global_config/config.yaml

Configuration

Examples of configuration and all available options can be found in the examples directory. I try to keep the configs well commented to explain all the features.

• Global config: The configuration for the CLI as a whole. Things like auth and defaults.
• Migration config: The configuration for an individual migration.

Documentation

Have a look in docs/ for further information.