Jenkins Gerrit Trigger that Checks on Travis CI results

jenkins_gerrit_travis.rb

# - gets latest Travis CI result and exits 0 (CR+1) or fails (CR-1)
# - gets the latest GitHub PR pull from Gerrit comments
# - warns if latest Gerrit patchset is newer than latest GitHub PR pull (because Travis results aren't the latest) 
# TODO: warn if latest Travis request is newer than latest GerritHub PR PR pull (because GerritHub needs to be updated)

require 'travis'
require 'travis/tools/github'
require 'json'

gerrit = {}

gerrit[:user]      = ENV.fetch('GERRIT_USER')       # NOTE: define this as a Jenkins env va
gerrit[:host]      = ENV.fetch('GERRIT_HOST')
gerrit[:port]      = ENV.fetch('GERRIT_PORT')
github_api_token   = ENV.fetch('GITHUB_API_TOKEN')  # TODO: travis can fetch this via .netrc
gerrit[:project]   = ENV.fetch('GERRIT_PROJECT')
gerrit[:change_id] = ENV.fetch('GERRIT_CHANGE_ID')
slug = gerrit[:project]
travis_token = Travis.github_auth( ENV['GITHUB_API_TOKEN'])
puts "Hello #{Travis::User.current.name}!"
repo = Travis::Repository.find(slug)
build = repo.builds.first
commit = build.commit

# Find the most recent pull request in the gerrit patchsets
gerrit[:query_json]    = %x{ssh -xp#{gerrit[:port]} #{gerrit[:user]}@#{gerrit[:host]} gerrit query --patch-sets --comments --format JSON change:#{gerrit[:change_id]}}
gerrit[:query_data]    =  JSON.parse gerrit[:query_json]
                                       .split(/\n{/)
                                       .first
gerrit[:pull_comments] = gerrit[:query_data]
                           .fetch('comments')
                           .select{|x| x.fetch('message') =~ %r{^GitHub Pull Request: https://api.github.com/repos/#{slug}/pulls} }
gerrit[:latest_pr] = {
   :timestamp => gerrit[:pull_comments]
                   .last['timestamp'],
   :number    => gerrit[:pull_comments]
                   .last['message']
                   .sub(%r{^GitHub Pull Request: https://api.github.com/repos/#{slug}/pulls/(\d+).*$}m, '\1' ),
}
gerrit[:latest_pr][:revision] = gerrit[:query_data]['patchSets']
                                  .select{|x| x['createdOn'].to_i == gerrit[:latest_pr][:timestamp] }
                                  .first
                                  .fetch('revision')

# Warn if GerritHub has been updated since the last GitHub PR pull
gerrit[:ps_timestamps] = gerrit[:query_data]['patchSets']
                           .map{|x| x['createdOn'] }
i                      = gerrit[:ps_timestamps]
                           .index(gerrit[:latest_pr][:timestamp])
max_i                  = gerrit[:ps_timestamps].size - 1
travis_is_trustworthy  = true
if i==max_i
  puts "#{slug} Pull request ##{gerrit[:latest_pr][:number]} is the most recent Patch Set in Gerrit (this is good)."
else
  width=80
  warn ''
  warn '-'*80
  warn "WARNING: *#{max_i-i}* patchsets have been submitted directly to Gerrit since `#{slug}` PR ##{gerrit[:latest_pr][:number]}; Travis CI will not have tested these changes!"
          .scan(/\S.{0,#{width-2}}\S(?=\s|$)|\S+/)
          .join("\n")
  warn '-'*80
  warn ''

  travis_is_trustworthy = false
end

request = repo
            .requests
            .select{|x| x.head_commit? && x.head_commit == gerrit[:latest_pr][:revision] }
            .first
build = repo
          .builds
          .select{ |x| x.commit_id? && x.commit_id == request.commit_id }
          .first

fail "FAILBARF: Travis build ##{build.number} for PR ##{build.pr_number} is not finished!" unless build.finished?
fail "FAILURE: Travis build ##{build.number} for PR ##{build.pr_number} failed!" unless build.green?

puts '-'*80
puts "SUCCESS! #{slug} PR# #{gerrit[:latest_pr][:number]} has passed Travis CI build #{build.number}!"
puts ''
puts "HOWEVER, subsequent direct Gerrit patchset make Travis' results untrustworthy." unless travis_is_trustworthy
puts '-'*80
exit 0