rake_heroku_deployer.rb
#Deploy and rollback on Heroku in staging and production
class RakeHerokuDeployer
def initialize app_env
@app = ENV["#{app_env.to_s.upcase}_APP"]
end
def run_migrations
push; turn_app_off; migrate; restart; turn_app_on; tag;
end
def deploy
push; restart; tag;
end
def rollback
turn_app_off; push_previous; restart; turn_app_on;
end
private
def push
current_branch = `git rev-parse --abbrev-ref HEAD`.chomp
branch_to_branch = (current_branch.length > 0) ? "#{current_branch}:master" : ""
puts 'Deploying site to Heroku ...'
puts "git push -f git@heroku.com:#{@app}.git #{branch_to_branch}"
puts `git push -f git@heroku.com:#{@app}.git #{branch_to_branch}`
end
def restart
puts 'Restarting app servers ...'
Bundler.with_clean_env { puts `heroku restart --app #{@app}` }
end
def tag
release_name = "#{@app}_release-#{Time.now.utc.strftime("%Y%m%d%H%M%S")}"
puts "Tagging release as '#{release_name}'"
puts `git tag -a #{release_name} -m 'Tagged release'`
puts `git push --tags git@heroku.com:#{@app}.git`
end
def migrate
puts 'Running database migrations ...'
Bundler.with_clean_env { puts `heroku run 'bundle exec rake db:migrate' --app #{@app}` }
end
def turn_app_off
puts 'Putting the app into maintenance mode ...'
Bundler.with_clean_env { puts `heroku maintenance:on --app #{@app}` }
end
def turn_app_on
puts 'Taking the app out of maintenance mode ...'
Bundler.with_clean_env { puts `heroku maintenance:off --app #{@app}` }
end
def push_previous
prefix = "#{@app}_release-"
releases = `git tag`.split("\n").select { |t| t[0..prefix.length-1] == prefix }.sort
current_release = releases.last
previous_release = releases[-2] if releases.length >= 2
if previous_release
puts "Rolling back to '#{previous_release}' ..."
puts "Checking out '#{previous_release}' in a new branch on local git repo ..."
puts `git checkout #{previous_release}`
puts `git checkout -b #{previous_release}`
puts "Removing tagged version '#{previous_release}' (now transformed in branch) ..."
puts `git tag -d #{previous_release}`
puts `git push git@heroku.com:#{@app}.git :refs/tags/#{previous_release}`
puts "Pushing '#{previous_release}' to Heroku master ..."
puts `git push git@heroku.com:#{@app}.git +#{previous_release}:master --force`
puts "Deleting rollbacked release '#{current_release}' ..."
puts `git tag -d #{current_release}`
puts `git push git@heroku.com:#{@app}.git :refs/tags/#{current_release}`
puts "Retagging release '#{previous_release}' in case to repeat this process (other rollbacks)..."
puts `git tag -a #{previous_release} -m 'Tagged release'`
puts `git push --tags git@heroku.com:#{@app}.git`
puts "Turning local repo checked out on master ..."
puts `git checkout master`
puts 'All done!'
else
puts "No release tags found - can't roll back!"
puts releases
end
end
end
namespace :deploy do
namespace :staging do
task :migrations do
deployer = RakeHerokuDeployer.new(:staging)
deployer.run_migrations
end
task :rollback do
deployer = RakeHerokuDeployer.new(:staging)
deployer.rollback
end
end
task :staging do
deployer = RakeHerokuDeployer.new(:staging)
deployer.deploy
end
namespace :production do
task :migrations do
deployer = RakeHerokuDeployer.new(:production)
deployer.run_migrations
end
task :rollback do
deployer = RakeHerokuDeployer.new(:production)
deployer.rollback
end
end
task :production do
deployer = RakeHerokuDeployer.new(:production)
deployer.deploy
end
end