Probot: Config

A Probot extension to easily share configs between repositories.

Setup

Just put common configuration keys in a common repository within your organization. Then reference this repository from config files with the same name.

# octocat/probot-settings:.github/test.yaml
shared1: will be merged
shared2: will also be merged

# octocat/repo1:.github/test.yaml
_extends: probot-settings
other: AAA

# octocat/repo2:.github/test.yaml
_extends: probot-settings
shared2: overrides shared2
other: BBB

# octocat/repo3:.github/test.yaml
other: CCC # standalone, does not extend other configs

Configs are deeply-merged. Nested objects do not have to be redefined completely. This is accomplished using deepmerge. When using probot-config in an app, you can pass options through to deepmerge.

You can also reference configurations from other organizations:

_extends: other/probot-settings
other: DDD

Additionally, you can specify a specific path for the configuration by appending a colon after the project.

_extends: probot-settings:.github/other_test.yaml
other: FFF

Inherited configurations are in the exact same location within the repositories.

# octocat/repo1:.github/test.yaml
_extends: .github
other: GGG

# octocat/.github:test.yaml
other: HHH

Additionally, if there is no config file, but there is a repo in the org named .github, it will be used as a base repository.

# octocat/repo1:.github/test.yaml <-- missing!
# octocat/.github:.github/test.yaml
other: III

Recipes

These recipes are specific to usage of the .github repo name, which is the recommended place to store your configuration files. Within the .github repository, your configuration must live in a .github/ folder.

An opt-in pattern

You may want to create a configuration that other projects in your org inherit from on an explicit opt-in basis. Example:

# octocat/.github:.github/_test.yaml
shared1: Will be inherited by repo1 and not repo2

# octocat/repo1:.github/test.yaml
# Inherits from octocat/.github:_test.yaml
_extends: .github:_test.yaml
# octocat/repo3:.github/test.yaml <--missing!
# Is not merged with another config.

An opt-out pattern

Alternatively, you may want to default to the config in your .github project and occasionally opt-out. Example:

# octocat/.github:.github/test.yaml
shared1: Will be inherited by repo1 and not repo2
# octocat/repo1:.github/test.yaml <-- missing!
# Uses octocat/.github:test.yaml instead

# octocat/repo3:.github/test.yaml <-- either empty or populated
# Will not inherit shared1, since no _extends field is specified

Usage

const getConfig = require('probot-config');

module.exports = robot => {
  robot.on('push', async context => {
    // Will look for 'test.yml' inside the '.github' folder
    const config = await getConfig(context, 'test.yml');
  });
};

Development

# Install dependencies
yarn

# Run the bot
yarn start

# Run test watchers
yarn test:watch

We use prettier for auto-formatting and eslint as linter. Both tools can automatically fix a lot of issues for you. To invoke them, simply run:

yarn fix

It is highly recommended to use VSCode and install the suggested extensions. They will configure your IDE to match the coding style, invoke auto formatters every time you save and run tests in the background for you. No need to run the watchers manually.