Unforgettable

How many times have you deployed a new release of a rails app and forgot to run a post-release rake task? Unforgettable tracks which tasks it has run previously, and which tasks still need to be invoked. Never forget to run post-release deploy rake tasks again!

Installation

Add this line to your application's Gemfile:

gem 'unforgettable'

And then execute:

bundle install

Run the generator to create a migration for the table that will be used to track the tasks that Unforgettable invokes.

rails g unforgettable:install
rails db:migrate

Usage

Generate new release tasks by running:

rails g unforgettable:task

This will create a new *.rake file in the folder lib/tasks/unforgettable. You can then insert whatever code you need to run during your next Unforgettable release.

You can trigger all previously uninvoked Unforgettable release tasks by running

$ rails unforgettable:release

Integration with Capistrano

You can integrate Unforgettable with Capistrano deploys by adding the below to your deploy.rb file.

namespace :deploy do
  desc 'Invoke any new Unforgettable release tasks'
  task :release do
    on roles(:app) do
      within release_path do
        with rails_env: fetch(:rails_env) do
          execute :rake, 'unforgettable:release'
        end
      end
    end
  end
end

after 'deploy:published',  'deploy:release'

Integration with Kamal

You can integrate Unforgettable with Kamal deploys by calling it from a post-deploy hook. Create a file post-deploy under the .kmal folder in the root of your project. The integration should look somethingt like:

$stdout.sync = true

$stderr.puts "Running bin/rails unforgettable:release on remote Docker containers..."

def get_container_name(host)
  base_name = "grogo-web"
  destination = ENV["KAMAL_DESTINATION"]
  version = ENV["KAMAL_VERSION"]

  potential_names = [
    [ base_name, destination, version ].reject { |v| v.to_s.strip.empty? }.join("-"),
    [ base_name, version ].reject { |v| v.to_s.strip.empty? }.join("-")
  ]

  # Check potential names to see which matches a container id on the server.
  potential_names.each do |name|
    command = "ssh deploy@#{host} \"docker ps --format '{{.Names}}' | grep #{name}\""
    result = `#{command}`.strip
    return result unless result.empty?
  end

  nil
end

def execute_task(host, container_name)
  task = "bin/rails unforgettable:release"
  remote_host = "deploy@#{host}"

  command = "ssh #{remote_host} 'docker exec #{container_name} #{task}'"
  unless system(command)
    $stderr.puts "Failed to execute rake task on remote Docker container: #{task} for host #{host}"
  end
end

ENV["KAMAL_HOSTS"].to_s.split(",").each do |host|
  container_name = get_container_name(host)
  execute_task(host, container_name)
end

Note: Kamal will not show the $stdout by default. Run Kamal in verbose mode with kamal deploy -v in order to see any output.

Rerunning Completed Tasks

Unforgettable records all tasks that have been run as a row on the unforgettable_releases table.

irb(main):002:0> Unforgettable::Release.all
=> #<ActiveRecord::Relation [#<Unforgettable::Release id: 1, version: "release_20210303203356", created_at: "2021-03-04 02:37:49", updated_at: "2021-03-04 02:37:49">]>

You can delete a previous record to force Unforgettable to run the task again.

Development

After checking out the repo, run bin/setup to install dependencies. Then, run rake test to run the tests. You can also run bin/console for an interactive prompt that will allow you to experiment.

To install this gem onto your local machine, run bundle exec rake install. To release a new version, update the version number in version.rb, and then run bundle exec rake release, which will create a git tag for the version, push git commits and the created tag, and push the .gem file to rubygems.org.

Contributing

Bug reports and pull requests are welcome on Bitbucket.

License

The gem is available as open source under the terms of the MIT License.