Full CI-CD with Heroku and Circle CI

circle.yml

machine:
  services:
    - 'postgresql'
    - 'redis'
  environment:
    REDIS_URL: 'redis://localhost:6379/0'
dependencies:
  pre:
    - 'git config user.email [email protected]'
    - 'git config user.name $CIRCLE_USERNAME'
    - 'bundle config --global frozen 1'
  cache_directories:
    - 'vendor/bundle'

test:
  override:
    - 'bundle exec rspec --format progress --color spec'

deployment:
  # Deploy the pre-release develop branch to staging
  staging:
    branch: develop
    commands:
      - 'WORKER_DYNOS=1 ./bin/heroku-deploy brandfolder-staging $CIRCLE_SHA1'

  # Deploy the production apps, production and admin
  production:
    branch: master
    commands:
      - 'WORKER_DYNOS=2 ./bin/heroku-deploy brandfolder-production $CIRCLE_SHA1'
      - 'heroku config -s -a brandfolder-production | xargs heroku config:set -a brandfolder-admin'
      - 'WORKER_DYNOS=0 ./bin/heroku-deploy brandfolder-admin $CIRCLE_SHA1'

  # Create a new app on each deploy of a branch in the feature namespace
  feature:
    branch:  /feature\/.*/
    commands:
      - 'mkdir -p ./tmp'
      - 'echo "bf-$CIRCLE_BRANCH" | sed "s/feature\///" | cut -c 1-30 > ./tmp/.appname'
      - 'heroku apps:destroy -a `cat ./tmp/.appname` --confirm `cat ./tmp/.appname` || true'
      - 'heroku create `cat ./tmp/.appname`'
      - 'heroku addons:add -a `cat ./tmp/.appname` heroku-postgresql'
      - 'heroku addons:add -a `cat ./tmp/.appname` sendgrid'
      - 'heroku addons:add -a `cat ./tmp/.appname` rediscloud'
      - 'heroku config:set -a `cat ./tmp/.appname` SECRET_KEY_BASE=`rake secret` LOCKUP_CODEWORD=cantshowthis'
      - 'SKIP_MIGRATIONS=true WORKER_DYNOS=0 ./bin/heroku-deploy `cat ./tmp/.appname` $CIRCLE_SHA1'
      - 'heroku pg:info --app `cat ./tmp/.appname` | grep --color=never -oE "HEROKU_POSTGRESQL[A-Z_]+" > ./tmp/.dbname'
      - 'heroku pg:reset --app `cat ./tmp/.appname` --confirm `cat ./tmp/.appname` `cat ./tmp/.dbname`'
      - 'bundle exec rake db:rebuild'
      - 'heroku pg:push --app `cat ./tmp/.appname` circle_ruby_test `cat ./tmp/.dbname`'
      - 'curl -f https://`cat ./tmp/.appname`.herokuapp.com'

  # Deploy all things in the hotfix namespace to the hotfix app and Copy settings from prod
  hotfix:
    branch:  /hotfix\/.*/
    commands:
      - 'heroku config -s -a brandfolder-production | xargs heroku config:set -a brandfolder-hotfix'
      - 'heroku config:set -a brandfolder-production CACHE_DISABLED=false'
      - 'WORKER_DYNOS=0 ./bin/heroku-deploy brandfolder-hotfix $CIRCLE_SHA1'

# Notify Kato of the Deploy
notify:
  webhooks:
    - url: 'https://api.kato.im/rooms/d14ec35cbb7cd962ab6e134be39614634bcf1fb2da856b821c8e2e4de1f98a3a/circleci'

heroky-deploy.rb

#!/usr/bin/env ruby

class Deployer

  LAST_MIGRATION_CMD = %{bundle exec rake db:migrate:status | grep "up" | grep -oE "[0-9]{8}[0-9]+" | tail -1}

  def self.deploy!
    new.deploy!
  end

  def initialize
    @appname = ARGV[0] || raise("appname required")
    @sha = ARGV[1] || raise("sha required")
    @worker_dynos = ENV['WORKER_DYNOS'] || "1"
  end

  def local_sha
    ENV['CIRCLE_SHA'] || `git rev-parse --verify HEAD`.strip
  end

  def remote_sha
    `heroku releases -n 1 -a #{@appname} | awk '/Deploy/ {print $3}'`.strip
  end

  def remote
    "[email protected]:#{@appname}.git"
  end

  def deploy!
    puts "deploying `#{@sha}` to `#{@appname}`"
    with_migrations do
      output = `git push #{remote} #{@sha}:refs/heads/master`
      !output.lines.last.to_s.include?("Aborting")
    end
    finish
  end

  private

  def finish
    system("heroku scale worker=#{@worker_dynos} --app #{@appname}")
    system("heroku maintenance:off --app #{@appname}")
    system('git stash pop', out: '/dev/null', err: '/dev/null')
    unless local_sha.include? remote_sha
      STDERR.puts("deploy invalid, remote: #{remote_sha} does not match #{local_sha}")
      exit 1
    end
  end

  def pending_migrations?
    return false if ENV['SKIP_MIGRATIONS']
    return true if ENV['FORCE_MIGRATIONS']
    @pending_migrations ||= begin
      `#{LAST_MIGRATION_CMD}`.strip !=
        `heroku run --app #{@appname} #{LAST_MIGRATION_CMD}`.strip
    end
  end

  def with_migrations(&block)
    return instance_eval(&block) unless pending_migrations?
    system("heroku maintenance:on --app #{@appname}") || exit(1)
    system("heroku ps:stop worker --app #{@appname}") || finish
    instance_eval(&block)
    system("heroku run rake db:migrate --app #{@appname}")
  end

end

Deployer.deploy!