app.rb

require 'sinatra'
require 'raven'
require 'json'
require 'openssl'
require 'yaml'

require File.join(File.dirname(__FILE__), 'redmine/issue')
require File.join(File.dirname(__FILE__), 'redmine/project')
require File.join(File.dirname(__FILE__), 'github/pull_request')
require File.join(File.dirname(__FILE__), 'github/status')
require File.join(File.dirname(__FILE__), 'repository')


post '/pull_request' do
  actions = {}

  request.body.rewind
  payload_body = request.body.read
  verify_signature(payload_body)

  event = request.env['HTTP_X_GITHUB_EVENT']
  halt unless ['pull_request', 'pull_request_review', 'pull_request_review_comment'].include?(event)

  payload = JSON.parse(payload_body)
  action = payload['action']
  event_act = "#{event}/#{action}"

  raise "unknown repo" unless payload['repository'] && (repo_name = payload['repository']['full_name'])
  raise "repo #{repo_name} not configured" if Repository[repo_name].nil?
  repo = Repository[repo_name]

  client = Octokit::Client.new(:access_token => ENV['GITHUB_OAUTH_TOKEN'])
  pull_request = PullRequest.new(repo, payload['pull_request'], client)

  halt if event == 'pull_request' && ['closed', 'labeled', 'unlabeled'].include?(action)
  halt if event_act == 'pull_request_review_comment/created'

  if ENV['GITHUB_OAUTH_TOKEN']
    if repo.link_to_redmine?
      pull_request.add_issue_links
    end

    if pull_request.dirty?
      message = <<EOM
@#{pull_request.author}, this pull request is currently not mergeable. Please rebase against the #{pull_request.target_branch} branch and push again.

If you have a remote called 'upstream' that points to this repository, you can do this by running:

```
    $ git pull --rebase upstream #{pull_request.target_branch}
```

---------------------------------------
This message was auto-generated by Foreman's [prprocessor](https://projects.theforeman.org/projects/foreman/wiki/PrProcessor)
EOM
      pull_request.add_comment(message)
    end

    pull_request.set_branch_labels(repo.branch_labels) if repo.branch_labels?

    actions['github'] = true
  end

  status 500 if actions.has_value?(false)
  content_type :json
  actions.to_json
end

get '/status' do
  locals = {}
  locals[:github_secret] = ENV['GITHUB_SECRET_TOKEN'] ? true : false
  locals[:redmine_key] = ENV['REDMINE_API_KEY'] ? true : false
  locals[:github_oauth_token] = ENV['GITHUB_OAUTH_TOKEN'] ? true : false
  locals[:configured_repos] = Repository.all.keys
  locals[:rate_limit] = Status.new.rate_limit

  erb :status, :locals => locals
end

# Hash of Redmine projects to linked GitHub repos
get '/redmine_repos' do
  content_type :json
  Repository.all.select { |repo,config| !config.redmine_project.nil? }.inject({}) do |output,(repo,config)|
    output[config.redmine_project] ||= {}
    output[config.redmine_project][repo] = config.branches
    output
  end.to_json
end

def verify_signature(payload_body)
  signature = 'sha1=' + OpenSSL::HMAC.hexdigest(OpenSSL::Digest.new('sha1'), ENV['GITHUB_SECRET_TOKEN'], payload_body)
  return halt 500, "Signatures didn't match!" unless Rack::Utils.secure_compare(signature, request.env['HTTP_X_HUB_SIGNATURE'])
end