db:rollback

[blackjid]

Hi, I wanted to rollback an application but the database was not rolled back.

What do you think about adding a deploy:db:rollback to this gem. This task could be also hooked after the deploy:reverted hook and run rake db:rollback

[kirs]

The best practice is usually to keep db schema/migrations capable with previous version of app.
For example if you rename the avatar column to userpic, instead of renaming the column directly, create a new column and then copy the values. After the release, you could remove the older column.

By using this trick, you will make the old-running code capable with the new schema (at the moment when DB is already migrated but app is not restarted yet).

But generally speaking, we could add this task as a optional and mention it in README.

[printercu]

@kirs this is good approach. Though db:rollback can be useful in staging and testing environments.

[stoivo]

Add lib/capistrano/tasks/db_rollback.rake

namespace :deploy do
  namespace :db do
    desc 'Rollback db'
      task rake: [:set_rails_env] do
        on release_roles([:db]) do
          within release_path do
            with rails_env: fetch(:rails_env) do
              execute :rake, "db:rollback
            end
          end
        end
      end
  end
end

That file will we autoloaded bu Capfile

# Load custom tasks from `lib/capistrano/tasks` if you have any defined
Dir.glob('lib/capistrano/tasks/*.rake').each { |r| import r }

[Tensho]

I agree with @printercu, during development/testing you may write incorrect migration, run it (within cap deploy), get error, re-write migration to make it correct, rollback (it'd be nice to do it within cap task), git push, cap deploy:migrate. It's especially useful for non-translational DDL dbs, like MySQL.
@kirs, is it considerable to add deploy:db:rollback task and rename deploy:migrate to deploy:db:migrate? I didn't read the whole history of capistrano-rails, that's why I'm asking about. Ready to provide PR ^_^

[tomdev]

This could get hairy when there are multiple migrations in a single release: rake db:rollback will only rollback the latest migration.

http://edgeguides.rubyonrails.org/active_record_migrations.html#rolling-back

It is also possible that only a few migration succeeded. Unsure what migration rake db:rollback would rollback. Hopefully the latest migration with up state in the schema_migrations table.

Just a few things to take into consideration here.

[printercu]

Unsure what migration rake db:rollback would rollback.

The latest successful.

STEP envvar can be passsed to rake from cap to rollback more migrations.