Welcome to knobots

This repository contains a number of github actions, which perform routine maintenance tasks for a variety of repositories, mostly for the knative org. In particular, this repo exists separately from other repos like https://github.com/knative/test-infra to enable using repository secrets to hold an access token for creating automated PRs.

If you just need to run a job periodically against a repo, https://github.com/knative-sandbox/.github/ holds template actions (in workflow-templates) which are copied to all the repos in Knative using the update-actions workflow in this repo.

Adding a repo

To add a repository here, there are two requirements:

1. Add an entry to repos.yaml containing an entry like this:

    - # name is the repository to operate on, think: https://github.com/{name}.git
      name: 'knative/pkg'
   
      # meta-organization is the github organization from which to sync Github
      # actions, think: https://github.com/{meta-organization}/.github
      # Actions are pulled from the workflow-templates directory.
      meta-organization: 'knative'
   
      # fork is the name of the fork to push to (otherwise a branch on the
      # main repo is used)
      fork: 'knative-automation/pkg'
   
      # channel is the channel on knative.slack.com to post when these actions fail.
      # These can be a direct-message to a username if prefixed with `@`
      channel: 'serving-api'
   
      # The list of users to which the PR should be `/assign` (only matters for Prow)
      # These should bias toward Github teams, but must exist within the target
      # organization (so knative[-sandbox] should use the team in their respective org).
      assignees: knative/foo-wg-leads

2. github.com/{fork}.git must be a fork of {name} (if specified) and knative-automation must have push access.

3. Repos can also optionally exclude certain jobs by adding their name to the appropriate {foo}-exclude.yaml file.

Adding new automation

This repo exists to run GitHub Actions to create automated management PRs against other repos in Knative. To add a new automated PR workflow (or update one of the existing workflows), it's worth understanding the different components in this repo:

• .github/workflows contains the actual GitHub Actions, in the Actions yaml format. These are (mostly) generated from the actions directories mentioned below, but a few are hand-maintained. For the generated workflows, run go run ./cmd/gen-actions at the root of the repo to regnerate the files, which will need to be checked in / PR'ed if changed.

• actions contains a set of GitHub Actions, either as Dockerfile actions or Javascript actions. Each directory under actions should contain the following:

  • action.yaml -- GitHub actions configuration. This file makes the directory an action.

  • Dockerfile (and probably entrypoint.sh) for Docker-based Actions OR index.js and package-lock.json et al for Javascript actions

  • If you want the action to be run against each repo configured in repos.yaml, add an auto-apply.yaml (schema here). This will cause the gen-actions tool (see below) to generate a github/workflows file which will fan out your command to all repos.

    It's expected that an auto-apply action will modify the checked-out workspace; these changes will export a create_pr variable (set to true if a PR shoud be created) and optionally a log output.

• cmd/gen-actions contains a script (main.go) and a template {actions_template.yaml) for generating fan-out PR generation workflows for all the actions directories which include an auto-apply.yaml.

  The parameters set in auto-apply.yaml are passed in to the actions_template.yaml, along with a github formatting function which passes through the remianing arguments to the GitHub Actions templating system (both use the same {{...}} syntax for templating, so any GitHub templating needs to be escaped from the Go templates).

  This script should stay fairly short; it's written in Go for two reasons:

  1. Go is a common language across Knative, and has sufficiently rich templating
  2. Using Go enables the script to work even on Windows machines, which is a nice benefit