PostgreSQL: Fix db:structure:load silent failure on SQL error

[ralinc]

PostgreSQL: Fix db:structure:load silent failure on SQL error

The command line flag "-v ON_ERROR_STOP=1" should be used when invoking psql to make sure errors are not suppressed.

Example: psql -v ON_ERROR_STOP=1 -q -f awesome-file.sql my-app-db

Fixes #23818.

[rails-bot]

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[ralinc]

cc @arthurnn

[kaspth]

r? @arthurnn

[arthurnn]

thanks , and sorry for taking so long to review it.

[danielricecodes]

@ralinc - I wish this feature had shipped with a way to disable this behavior. I upgraded to Rails 5.1 and this change has broken all of my CI and Heroku automation. The CI server appears to be running rake db:structure:load more than once and this change has rendered this rake task non-idempotent.

I have no easy way to disable this feature b/c an environmental flag has been embedded in this psql command tail for me with no easy way to undo this. I for one, do not desire this flag on my system. At least not right now.

I'm also confused by the OP's original issue and am not 100% sure why this would even be approved and merged into ActiveRecord. A command line flag like this can be added on one's own by just appending it onto their command like this: rake db:structure:load ON_ERROR_STOP=1. Futhermore, psql does not suppress the errors it encounters without this flag. They are clearly visible in the Terminal and the Rails log (on OSX at least). If these are suppressed on other systems, then that must be due to platform differences in psql or how those platforms treat STDIN and STDERR streams - but I don't see how that would merit forcing environmental flags onto everyone using ActiveRecord 5.1.

IMHO, this was a hastily implemented and not thoroughly reviewed feature. Is it possible to roll it back? (I know I can by forking ActiveRecord ;) )

[kubakrzempek]

@danielricecodes I don't like the change either but have managed to work around this by creating a custom task that leverages .structure_load_flags

namespace :db do
  namespace :structure do
    desc "Disable exit-on-error behaviour when loading db structure in postgresql"
    task disable_errors: :environment do
      ActiveRecord::Tasks::DatabaseTasks.structure_load_flags = ["-v", "ON_ERROR_STOP=0"]
    end
  end
end

So, for my heroku automation it is now bin/rails db:structure:disable_errors db:structure:load