Post deploy hook to push a Rails app from Solano Labs (Tddium) to AWS OpsWorks if the CI build is successful

tddium.rake

# To set up:
#
# Add this file to /lib/tasks/tddium.rake
#
# Create an IAM user on AWS with no special policies, then add the access
# key and secret key to your Tddium suite config like this:
#
# cd /your/local/app/directory
# tddium config:add suite AWS_ACCESS_KEY yourkeyhere
# tddium config:add suite AWS_SECRET_KEY yoursecrethere
#
# Then, give the user deploy permissions in the stack settings:
# OpsWorks --> your stack --> Users (top right)
# Import IAM Users
# Then Edit the user and choose 'deploy' for the permissions and press save
#
# Now get the stack id and app id from their respective settings pages in AWS
# and add them too. They are both labelled 'OpsWorks ID'.
#
# tddium config:add suite OPSWORKS_STACK_ID yourstackidhere
# tddium config:add suite OPSWORKS_APP_ID yourappidhere

require 'timeout'
require 'aws-sdk-v1'

ENV['CI_DEPLOYMENT_BRANCH'] ||= 'master'

def current_branch
  `git symbolic-ref HEAD 2>/dev/null | cut -d"/" -f 3-`.strip
end

class OpsWorksDeployer

  attr_accessor :deployment_id

  def deploy
    set_aws_credentials
    send_deployment_api_call_to_aws
    wait_to_see_what_happened
  end

  protected

  def start_time
    @start_time ||= Time.now
  end

  def timeout_seconds
    600
  end

  def time_elapsed
    Time.now - start_time
  end

  def current_deploy_status
    result = opsworks.client.describe_deployments deployment_ids: [deployment_id]
    result[:deployments].first[:status]
  end

  def time_between_status_checks
    5 # seconds
  end

  def wait_to_see_what_happened
    while true do

      status = current_deploy_status

      case status
        when 'running'
          sleep time_between_status_checks
        when 'failed'
          raise "Deployment #{deployment_id} failed. Check the OpsWorks logs for details."
        when 'successful'
          return
        else # Some weird outcome?
          if time_elapsed < timeout_seconds
            sleep time_between_status_checks
          else
            raise "Deployment #{deployment_id} timed out after #{timeout_seconds} seconds. Status: #{status}"
          end
      end
    end
  end

  def set_aws_credentials
    # Do not include the region here. It makes it hang on the connection.
    AWS.config(access_key_id: aws_access_key, secret_access_key: aws_secret_key)
  end

  def send_deployment_api_call_to_aws
    result = opsworks.client.create_deployment stack_id: stack_id,
                                      app_id: app_id,
                                      command: {"name" => "deploy",
                                                "args" => {"migrate" => ["true"]}}
    @deployment_id = result[:deployment_id]
  end

  def opsworks
    @opsworks ||= AWS::OpsWorks.new
  end

  def aws_access_key
    ENV.fetch('AWS_ACCESS_KEY')
  end

  def aws_secret_key
    ENV.fetch('AWS_SECRET_KEY')
  end

  def stack_id
    ENV.fetch 'OPSWORKS_STACK_ID'
  end

  def app_id
    ENV.fetch 'OPSWORKS_APP_ID'
  end
end

namespace :tddium do
  desc "Run post-build script"
  task :post_build_hook do
    # Print out status information
    puts "Solano CI? " + ENV.member?('TDDIUM').to_s
    puts "status " + ENV['TDDIUM_BUILD_STATUS']
    puts "on_tracked_branch? " + on_tracked_branch?.inspect
    puts "deploy? " + deploy?.inspect

    if deploy?
      Rake::Task["deploy:production"].execute
    end
  end

  private

  def deploy?
    result = ENV.member?('TDDIUM')
    result &&= ENV['TDDIUM_BUILD_STATUS'] == 'passed'
    result && on_tracked_branch?
  end

  def on_tracked_branch?
    current_branch == ENV['CI_DEPLOYMENT_BRANCH']
  end
end

namespace :deploy do
  desc "Deploy master branch to production server"
  task :production do
    Timeout::timeout(600) do
      deploy
    end
  end

  private

  def deploy
    allow_connections_without_webmock_interfering
    OpsWorksDeployer.new.deploy
  end

  def allow_connections_without_webmock_interfering
    if WebMock
      WebMock.allow_net_connect!
    end
  end

end