Jenkins build and deploy script per Github branch

ci_runner.rb

# Build script for Jenkins. This builds the checked out code and will deploy it if the commit came from
# an environment specified in DEPLOYABLE_ENVIRONMENTS after a successful build.
require 'open-uri'

HIPCHAT_AUTH_TOKEN = "FILL ME IN"
HIPCHAT_ROOM = "FILL ME IN"
PROJECT_NAME = "FILL ME IN"
STAGING_URL = "https://staging.example.com"
PRODUCTION_URL = "https://www.example.com"

# Update this constant with branches from which we should deploy
DEPLOYABLE_ENVIRONMENTS = [
                            {
                              :branch => "develop",
                              :environment => "FILL ME IN",
                              :msg => "#{PROJECT_NAME} deployed to staging (#{STAGING_URL})",
                              :url => STAGING_URL
                            },
                            {
                              :branch => "master",
                              :environment => "FILL ME IN",
                              :msg => "#{PROJECT_NAME} deployed to production (#{PRODUCTION_URL})",
                              :url => PRODUCTION_URL
                            }
                          ]

# Define methods to print out colors.
def colorize(text, color_code)
  "\e[#{color_code}m#{text}\e[0m"
end
def red(text); colorize(text, 31); end
def green(text); colorize(text, 32); end
def yellow(text); colorize(text, 33); end

# Check out a branch from git. Optionally you can specify :rebase => true and this will rebase from the :origin branch,
# which defaults to "origin"
def checkout(branch, opts = {})
  `git checkout #{branch}`
  if opts[:rebase]
    origin = opts[:origin] || "origin"
    `git rebase #{origin}/#{branch}`
  end
end

# Returns the SHA1 hash of the most recent git commit.
def most_recent_commit
  `git log | head -n 1 | cut -d " " -f 2`
end

# Stash the commit that we are about to build so we can determine which branch it came from.
$commit_of_build = most_recent_commit

# Returns the current branch we're building on, or nil if we're not on a branch.
def current_branch
  branch = `git branch | grep "*" | cut -d " " -f 2`.strip
  branch == "(no" ? nil : branch
end

# Returns the SHA1 hash of the most recent git commit on branch
def last_commit_on_branch(branch)
  checkout(branch, :rebase => true)
  most_recent_commit
end

# Runs bundle install and bundle exec rake
def build
  #########################
  # RUN BUILD SCRIPT HERE #
  #########################
end

def run_smoke_tests(url)
  ####################################
  # RUN SMOKE TEST HERE, RETURN BOOL #
  ####################################
end

def rollback(environment)
  ###########################
  # ROLLBACK CODE GOES HERE #
  ###########################
end

# Posts a message to HipChat
def hipchat(msg, color = "purple", strong = true)
  puts(green("Posting to HipChat: \"#{msg}\""))
  if strong
    msg = "<strong>#{msg}</strong>"
  end
  msg = URI.encode(msg)
  `curl -d "auth_token=#{HIPCHAT_AUTH_TOKEN}&room_id=#{HIPCHAT_ROOM}&from=Jenkins&color=#{color}&message=#{msg}" https://api.hipchat.com/v1/rooms/message`
end

# Iterates over DEPLOYABLE_ENVIRONMENTS to see if those caused the commit, and if so, deploys to them.
def deploy
  DEPLOYABLE_ENVIRONMENTS.each do |env|
    commit_occurred_on_branch = $commit_of_build == last_commit_on_branch(env[:branch])
    if commit_occurred_on_branch
      puts(green("Deploying to #{env[:environment]}"))

      ########################
      # RUN DEPLOY CODE HERE #
      ########################

      if $?.success?
        hipchat(env[:msg])
        success = run_smoke_tests(env[:url])
        if !success
          msg = "Smoke tests failed for #{PROJECT_NAME} #{env[:url]}! Rolling back."
          puts(msg)
          hipchat(msg, :red)
          rollback(env[:environment])
          hipchat("Rollback complete for #{PRODUCTION_URL} #{env[:environment]} (#{env[:url]})")
        end
      else
        hipchat("#{PROJECT_NAME} did not deploy successfully to #{env[:environment]} (#{env[:url]})", :red)
      end
    end
  end
end

##############################
##### BEGIN BUILD SCRIPT #####
##############################
build()
deploy()