When should Discourse upgrade to Rails 5?

david · September 27, 2017, 7:39pm

@tgxworld I think the rails 5 upgrade may have introduced an issue with error handling in the application controller.

I think I’ve tracked it down to any call to rescue_discourse_actions which has include_ember: true. I use this in my category-lockdown plugin (hence why I noticed), but it is also used in core.

One example of this is the recovery from an InvalidAccess exception:

https://github.com/discourse/discourse/blob/master/app/controllers/application_controller.rb#L143-L150

If you try and access a topic you do not have access to, the server throws a 500 error. This is the stack trace I get when reproducing on my dev instance:

Stack Trace

ActionView::MissingTemplate - Missing template topics/show, application/show with {:locale=>[:en], :formats=>[:json], :variants=>[], :handlers=>[:raw, :erb, :html, :builder, :ruby]}. Searched in:
  * "/Users/David/Web-Projects/discourse/app/views"
  * "/Users/David/Web-Projects/discourse/plugins/docker_manager/app/views"
  * "/Users/David/.rvm/gems/ruby-2.3.4/gems/discourse-qunit-rails-0.0.11/app/views"
:
  actionview (5.1.3) lib/action_view/path_set.rb:46:in `find'
  actionview (5.1.3) lib/action_view/lookup_context.rb:116:in `find'
  actionview (5.1.3) lib/action_view/renderer/abstract_renderer.rb:18:in `find_template'
  actionview (5.1.3) lib/action_view/renderer/template_renderer.rb:38:in `determine_template'
  actionview (5.1.3) lib/action_view/renderer/template_renderer.rb:8:in `render'
  actionview (5.1.3) lib/action_view/renderer/renderer.rb:42:in `render_template'
  actionview (5.1.3) lib/action_view/renderer/renderer.rb:23:in `render'
  actionview (5.1.3) lib/action_view/rendering.rb:103:in `_render_template'
  actionpack (5.1.3) lib/action_controller/metal/streaming.rb:217:in `_render_template'
  actionview (5.1.3) lib/action_view/rendering.rb:83:in `render_to_body'
  actionpack (5.1.3) lib/action_controller/metal/rendering.rb:52:in `render_to_body'
  actionpack (5.1.3) lib/action_controller/metal/renderers.rb:141:in `render_to_body'
  actionpack (5.1.3) lib/abstract_controller/rendering.rb:24:in `render'
  actionpack (5.1.3) lib/action_controller/metal/rendering.rb:36:in `render'
  actionpack (5.1.3) lib/action_controller/metal/instrumentation.rb:44:in `block (2 levels) in render'
  activesupport (5.1.3) lib/active_support/core_ext/benchmark.rb:12:in `block in ms'
  /Users/David/.rvm/rubies/ruby-2.3.4/lib/ruby/2.3.0/benchmark.rb:308:in `realtime'
  activesupport (5.1.3) lib/active_support/core_ext/benchmark.rb:12:in `ms'
  actionpack (5.1.3) lib/action_controller/metal/instrumentation.rb:44:in `block in render'
  actionpack (5.1.3) lib/action_controller/metal/instrumentation.rb:87:in `cleanup_view_runtime'
  activerecord (5.1.3) lib/active_record/railties/controller_runtime.rb:29:in `cleanup_view_runtime'
  actionpack (5.1.3) lib/action_controller/metal/instrumentation.rb:43:in `render'
  app/controllers/application_controller.rb:165:in `rescue_discourse_actions'
  app/controllers/application_controller.rb:144:in `block in <class:ApplicationController>'
  activesupport (5.1.3) lib/active_support/rescuable.rb:115:in `block in handler_for_rescue'
  activesupport (5.1.3) lib/active_support/rescuable.rb:91:in `rescue_with_handler'
  activesupport (5.1.3) lib/active_support/rescuable.rb:164:in `rescue_with_handler'
  actionpack (5.1.3) lib/action_controller/metal/rescue.rb:23:in `rescue in process_action'
  actionpack (5.1.3) lib/action_controller/metal/rescue.rb:20:in `process_action'
  actionpack (5.1.3) lib/action_controller/metal/instrumentation.rb:32:in `block in process_action'
  activesupport (5.1.3) lib/active_support/notifications.rb:166:in `block in instrument'
  activesupport (5.1.3) lib/active_support/notifications/instrumenter.rb:21:in `instrument'
  activesupport (5.1.3) lib/active_support/notifications.rb:166:in `instrument'
  actionpack (5.1.3) lib/action_controller/metal/instrumentation.rb:30:in `process_action'
  actionpack (5.1.3) lib/action_controller/metal/params_wrapper.rb:252:in `process_action'
  activerecord (5.1.3) lib/active_record/railties/controller_runtime.rb:22:in `process_action'
  actionpack (5.1.3) lib/abstract_controller/base.rb:124:in `process'
  actionview (5.1.3) lib/action_view/rendering.rb:30:in `process'
  rack-mini-profiler (0.10.5) lib/mini_profiler/profiling_methods.rb:102:in `block in profile_method'
  actionpack (5.1.3) lib/action_controller/metal.rb:189:in `dispatch'
  actionpack (5.1.3) lib/action_controller/metal.rb:253:in `dispatch'
  actionpack (5.1.3) lib/action_dispatch/routing/route_set.rb:49:in `dispatch'
  actionpack (5.1.3) lib/action_dispatch/routing/route_set.rb:31:in `serve'
  actionpack (5.1.3) lib/action_dispatch/journey/router.rb:46:in `block in serve'
  actionpack (5.1.3) lib/action_dispatch/journey/router.rb:33:in `serve'
  actionpack (5.1.3) lib/action_dispatch/routing/route_set.rb:834:in `call'
  rack-protection (2.0.0) lib/rack/protection/frame_options.rb:31:in `call'
  omniauth (1.6.1) lib/omniauth/strategy.rb:189:in `call!'
  omniauth (1.6.1) lib/omniauth/strategy.rb:167:in `call'
  omniauth (1.6.1) lib/omniauth/strategy.rb:189:in `call!'
  omniauth (1.6.1) lib/omniauth/strategy.rb:167:in `call'
  omniauth (1.6.1) lib/omniauth/strategy.rb:189:in `call!'
  omniauth (1.6.1) lib/omniauth/strategy.rb:167:in `call'
  omniauth (1.6.1) lib/omniauth/strategy.rb:189:in `call!'
  omniauth (1.6.1) lib/omniauth/strategy.rb:167:in `call'
  omniauth (1.6.1) lib/omniauth/strategy.rb:189:in `call!'
  omniauth (1.6.1) lib/omniauth/strategy.rb:167:in `call'
  omniauth (1.6.1) lib/omniauth/strategy.rb:189:in `call!'
  omniauth (1.6.1) lib/omniauth/strategy.rb:167:in `call'
  omniauth (1.6.1) lib/omniauth/builder.rb:63:in `call'
  rack (2.0.3) lib/rack/conditional_get.rb:25:in `call'
  rack (2.0.3) lib/rack/head.rb:12:in `call'
  rack (2.0.3) lib/rack/session/abstract/id.rb:232:in `context'
  rack (2.0.3) lib/rack/session/abstract/id.rb:226:in `call'
  actionpack (5.1.3) lib/action_dispatch/middleware/cookies.rb:613:in `call'
  activerecord (5.1.3) lib/active_record/migration.rb:556:in `call'
  actionpack (5.1.3) lib/action_dispatch/middleware/callbacks.rb:26:in `block in call'
  activesupport (5.1.3) lib/active_support/callbacks.rb:97:in `run_callbacks'
  actionpack (5.1.3) lib/action_dispatch/middleware/callbacks.rb:24:in `call'
  actionpack (5.1.3) lib/action_dispatch/middleware/executor.rb:12:in `call'
  better_errors (2.1.1) lib/better_errors/middleware.rb:84:in `protected_app_call'
  better_errors (2.1.1) lib/better_errors/middleware.rb:79:in `better_errors_call'
  better_errors (2.1.1) lib/better_errors/middleware.rb:57:in `call'
  actionpack (5.1.3) lib/action_dispatch/middleware/debug_exceptions.rb:59:in `call'
  actionpack (5.1.3) lib/action_dispatch/middleware/show_exceptions.rb:31:in `call'
  logster (1.2.7) lib/logster/middleware/reporter.rb:31:in `call'
  railties (5.1.3) lib/rails/rack/logger.rb:36:in `call_app'
  railties (5.1.3) lib/rails/rack/logger.rb:26:in `call'
  config/initializers/100-quiet_logger.rb:16:in `call'
  config/initializers/100-silence_logger.rb:29:in `call'
  actionpack (5.1.3) lib/action_dispatch/middleware/remote_ip.rb:79:in `call'
  actionpack (5.1.3) lib/action_dispatch/middleware/request_id.rb:25:in `call'
  rack (2.0.3) lib/rack/method_override.rb:22:in `call'
  rack (2.0.3) lib/rack/runtime.rb:22:in `call'
  actionpack (5.1.3) lib/action_dispatch/middleware/executor.rb:12:in `call'
  actionpack (5.1.3) lib/action_dispatch/middleware/static.rb:125:in `call'
  actionpack (5.1.3) lib/action_dispatch/middleware/static.rb:125:in `call'
  rack (2.0.3) lib/rack/sendfile.rb:111:in `call'
  lib/middleware/missing_avatars.rb:21:in `call'
  lib/middleware/turbo_dev.rb:34:in `call'
  rack-mini-profiler (0.10.5) lib/mini_profiler/profiler.rb:282:in `call'
  message_bus (2.0.5) lib/message_bus/rack/middleware.rb:63:in `call'
  railties (5.1.3) lib/rails/engine.rb:522:in `call'
  railties (5.1.3) lib/rails/railtie.rb:185:in `method_missing'
  rack (2.0.3) lib/rack/urlmap.rb:68:in `block in call'
  rack (2.0.3) lib/rack/urlmap.rb:53:in `call'
  puma (3.9.1) lib/puma/configuration.rb:224:in `call'
  puma (3.9.1) lib/puma/server.rb:602:in `handle_request'
  puma (3.9.1) lib/puma/server.rb:435:in `process_client'
  puma (3.9.1) lib/puma/server.rb:299:in `block in run'
  puma (3.9.1) lib/puma/thread_pool.rb:120:in `block in spawn_thread'

For a live example, try accessing a topic you do not have access to on meta (e.g. this one in incognito mode). Browser console shows a 500 error, and I would assume you have a sea of errors in the server logs.

Edit: it also looks like the handling of topic redirects is broken. For example, a link to

https://meta.discourse.org/t/automatic-second-post-wiki/70791/7

works fine

but if I omit the title:

https://meta.discourse.org/t/70791/7

bad things happen

Topic		Replies	Views
Discourse as Your First Rails App Blog	128	41426	January 18, 2018
Rails plugin generator Announcements	50	12518	August 20, 2021
Upgrading Discourse to Rails 6 Dev	17	3812	January 7, 2020
Edits not displayed and timing out Bug fixed	12	169	November 9, 2024
Preparing for Discourse's upgrade to Ember 5 Announcements	56	6960	April 8, 2024

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