GitHub PR Labels Buildkite Plugin

Retrieve the labels associated with a GitHub Pull Request and publish them as environment variable and/or build meta-data.

Multiple labels will appear as comma-separated values.

The only difference in this fork from the upstream is the alternate source functionality.

Pre-requisites for private repositories

When using with a private repository, a valid GitHub token (PAT) must be provided. It can be provided either inside an environment variable or inside a file. Other plugins can be used before this plugin to set up the token.

Examples

Publish the labels as environment variable (public repository)

The comma-separated list of labels will be published in the PULL_REQUEST_LABELS environment variable. The variable is accessible to all subsequent commands and plugins within the same step.

steps:
  - command: echo $$PULL_REQUEST_LABELS
    plugins:
      - blstrco/github-pr-labels#main:
          publish-env-var: PULL_REQUEST_LABELS

Publish the labels as environment variable (private repository)

In this example a valid GitHub token has been pre-loaded inside the GITHUB_TOKEN environment variable

The comma-separated list of labels will be published in the PULL_REQUEST_LABELS environment variable. The variable is accessible to all subsequent commands and plugins within the same step.

steps:
  - command: echo $$PULL_REQUEST_LABELS
    plugins:
      - blstrco/github-pr-labels#main:
          token-from:
            env: GITHUB_TOKEN
          publish-env-var: PULL_REQUEST_LABELS

Publish the labels as build meta-data (private repository)

In this example a valid GitHub token has been pre-loaded inside the /etc/github/token file

The comma-separated list of labels will be available in the pull-request-labels meta-data key. The meta-data key is accessible on all subsequent steps of the pipeline.

steps:
  - command: buildkite-agent meta-data get pull-request-labels
    plugins:
      - blstrco/github-pr-labels#main:
          token-from:
            file: /etc/github/token
          publish-metadata-key: pull-request-labels
  - wait: ~
  - command: buildkite-agent meta-data get pull-request-labels

Getting labels from another source

In situations where the branch is not tied to a pull request, this fork provides a mechanism for retrieving the pull request number from another source using one or many regex patterns (passed to egrep (chained if array)).

This could be used with BUILDKITE_MESSAGE if using default squash commit messages, for e.g.:

steps:
  - command: buildkite-agent meta-data get pull-request-labels
    plugins:
      - blstrco/github-pr-labels#main:
          token-from:
            file: /etc/github/token
          publish-metadata-key: pull-request-labels
          pull-request-id-from:
            pattern:
              - '\(#[0-9]+)$'
              - '[0-9]+'
            source: "$$BUILDKITE_MESSAGE"
  - wait: ~
  - command: buildkite-agent meta-data get pull-request-labels

This feature is currently on supported on main and master branches.

Configuration

token-from (optional, {file | env})

Datasource for the github token. One of file or env subkeys must be provided

file (optional[mutually-exclusive with env], string)

File containing the github token

env (optional[mutually-exclusive with file], string)

Env var containing the github token

publish-env-var (optional, string)

Enables publishing the labels in an environment variable of specified name

publish-metadata-key (optional, string)

Enables publishing the labels in a build meta-data key of specified name

Developing

To run the tests:

docker-compose run --rm tests

Contributing

1. Fork the repo
2. Make the changes
3. Run the tests
4. Commit and push your changes
5. Send a pull request