Creating a GitHub stale repositories cleanup bot with Boomerang Flow

Tyson Lawrie
4 min readJun 1, 2021


Why Boomerang Flow?

Boomerang Flow is a no-code event-driven cloud-native workflow automation tool and is an open-source project.

There are a number of tools that you can use to create a GitHub bot; GitHub Actions, Netlify, Heroku, or any functions hosting cloud, with various skill levels required.

The following will give you a view on doing the same with no-code automation.

Why a repositories bot?

This particular bot is useful to identify if new repositories are being created and you want to make sure to keep a clean GitHub Organization. Its possible that repositories get created for testing purposes and forgotten about, or are created and now need to be managed with issue templates or a license.

Creating the Workflow

Boomerang Flows Create a new Workflow view

The default landing page is the Workflows screen and in your space will be the ability to create a new workflow.

Wiring together the bot

Boomerang Flows Workflow Editor view with Tasks Parameters

On the Workflow Editor screen, you can drag and drop a number of tasks from the palette providing a great end-user experience. For advanced management, these tasks are Tekton defined YAML and can be managed via the Task Manager.

Find Repositories in Org

Drag on the Find Repositories in Org Task and add the required specifics.

Custom Task Name: `Find Repositories`.
Note: This will be used later on to get the result parameters.

Send Simple Slack Message

Drag on the Send Simple Slack Message Task and add the required specifics.

Note: We make use of the prior tasks' result parameters to output the found repositories.

Wire the Tasks together

Drag and drop the lines between the tasks. You can make use of the Task state as well by changing it to only proceed on success.

Find out more information about Link and Tasks states.

Configure a Schedule Trigger

Boomerang Flows Workflow Editor & Configuration view

We want this to run on a weekly or monthly schedule. On the Configure tab under Triggers, enable the Scheduler and then click Change Schedule.

In the basic view you can set a weekly schedule or you can switch to the advanced view and set any cron based schedule.

The Activity

Boomerang Flows Workflow Activity view

Boomerang Flow provides an activity view where you can see whats running, dynamically tail logs, and view a Tasks Result Parameters.

Boomerang Flows Workflow Activity view with a Tasks Result Parameters

Result Parameters are important in this Workflow as it is how we passed information from the repositories listing Task that connected to GitHub, to the Slack messaging Task.

The Result

The bots message in Slack

And as you can see, the workflow resulted in a message post to a Slack channel. This is a really easy, no-code way of creating a bot.

What did we achieve

- A no-code workflow
- No configuration of setting up a function running in a cloud
- No YAML!
- Easy to use interface for providing information
- A bot that can keep on running and be refined with a filterable list.

Future Steps

If you are confident that the bot is now finding the correct repositories, you can implement a repository deletion mechanism or raise a GitHub issue to close the repository.

Show your support

Show your support if this helped you:

- ⭐️ the GitHub repository
- 💬 Follow us on Twitter
- Install the project on your own Kubernetes cluster
- 🙏 Join us and help contribute



Tyson Lawrie

A software engineer and automation enthusiast, made in Australia, Ex New Yorker. Building and Maintaining