I am running into a situation where I can''t ensure the proper sequence of Rack middlewares. I have two middlewares in my Rails 3.0.9 stack: 1- ExceptionNotifier 2- ActionDispatch::ShowExceptions The first one is a gem<https://www.ruby-toolbox.com/projects/exception_notification>that notifies me (via email) of any unhandled exception thrown by my app. The second one is to handle the display of error pages. The call methods of these two are straightforward. The first one calls its predecessor and catches resulting exception, sends email and re-raises the same exception. The second one just enhances already available functionality in Rails to render properly formatted pages. The second one does not raise any exception and thus renders the response and everything is all right. In an initializer, I have a code <https://gist.github.com/4019271> (link to gist) that inserts the 1st one before the 2nd one. But in reality, ActionDispatch::ShowException is always called first and when I get an exceptional condition, the properly formatted error pages are displayed, but email is never sent because the ExceptionNotifier is never called. Does that make sense? Anybody has any comment about how I can make it do the right thing? (Call ExceptionNotifier first and ShowExceptions later). Regards, Kedar PS: output of rake middleware with this setup: use ActionDispatch::Static use Rack::Lock use ActiveSupport::Cache::Strategy::LocalCache use Rack::Runtime use Rails::Rack::Logger *use ExceptionNotifier* *use ActionDispatch::ShowExceptions* use ActionDispatch::ShowExceptions use ActionDispatch::RemoteIp use Rack::Sendfile use ActionDispatch::Callbacks use ActiveRecord::ConnectionAdapters::ConnectionManagement use ActiveRecord::QueryCache use ActionDispatch::Cookies use ActionDispatch::Session::CookieStore use ActionDispatch::Flash use ActionDispatch::ParamsParser use Rack::MethodOverride use ActionDispatch::Head use ActionDispatch::BestStandardsSupport use OAuth2::Provider::Rack::Middleware use OmniAuth::Builder run MyApp::Application.routes -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org For more options, visit https://groups.google.com/groups/opt_out.
On Monday, 5 November 2012 19:39:45 UTC-5, Kedar Mhaswade wrote:> > I am running into a situation where I can''t ensure the proper sequence of > Rack middlewares. I have two middlewares in my Rails 3.0.9 stack: > > 1- ExceptionNotifier > 2- ActionDispatch::ShowExceptions > > The first one is a gem<https://www.ruby-toolbox.com/projects/exception_notification>that notifies me (via email) of any unhandled exception thrown by my app. > The second one is to handle the display of error pages. The call methods of > these two are straightforward. The first one calls its predecessor and > catches resulting exception, sends email and re-raises the same exception. > The second one just enhances already available functionality in Rails to > render properly formatted pages. The second one does not raise any > exception and thus renders the response and everything is all right. > > In an initializer, I have a code <https://gist.github.com/4019271> (link > to gist) that inserts the 1st one before the 2nd one. > > But in reality, ActionDispatch::ShowException is always called first and > when I get an exceptional condition, the properly formatted error pages are > displayed, but email is never sent because the ExceptionNotifier is never > called. > > Does that make sense? Anybody has any comment about how I can make it do > the right thing? (Call ExceptionNotifier first and ShowExceptions later). > > Regards, > Kedar > > PS: output of rake middleware with this setup: > > use ActionDispatch::Static > use Rack::Lock > use ActiveSupport::Cache::Strategy::LocalCache > use Rack::Runtime > use Rails::Rack::Logger > *use ExceptionNotifier* > *use ActionDispatch::ShowExceptions* > use ActionDispatch::ShowExceptions > use ActionDispatch::RemoteIp > use Rack::Sendfile > use ActionDispatch::Callbacks > use ActiveRecord::ConnectionAdapters::ConnectionManagement > use ActiveRecord::QueryCache > use ActionDispatch::Cookies > use ActionDispatch::Session::CookieStore > use ActionDispatch::Flash > use ActionDispatch::ParamsParser > use Rack::MethodOverride > use ActionDispatch::Head > use ActionDispatch::BestStandardsSupport > use OAuth2::Provider::Rack::Middleware > use OmniAuth::Builder > run MyApp::Application.routes > >The best way to visualize the process here is to imagine the request comes in at the *top* of the middleware stack (AD::Static here) and is passed down to successive middlewares until it generates a response. The response then flows back *up* the stack until it gets to the top and is handed to the web server for delivery to the user. Short story shorter, you need to put them in the opposite order - ShowExceptions is rescuing the exception so ExceptionNotifier never sees it. --Matt Jones -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org To view this discussion on the web visit https://groups.google.com/d/msg/rubyonrails-talk/-/Z3L8G7xqLfUJ. For more options, visit https://groups.google.com/groups/opt_out.
Kedar Mhaswade
2012-Nov-19 13:01 UTC
Re: Configuring proper sequence of Rack middlewares ...
> > >> > The best way to visualize the process here is to imagine the request comes > in at the *top* of the middleware stack (AD::Static here) and is passed > down to successive middlewares until it generates a response. The response > then flows back *up* the stack until it gets to the top and is handed to > the web server for delivery to the user. > > Short story shorter, you need to put them in the opposite order - > ShowExceptions is rescuing the exception so ExceptionNotifier never sees it. >Thank you, Matt Jones. I changed the sequence so that ExceptionNotifier middleware is below the ShowExceptions middleware in the stack (as reported by rake middleware). In this case however, I am not seeing the desired effect. Is it because ShowExceptions::render_exeption_with_template, as written, actually renders the response (the formatted error page) and does not re-raise the exception? Should I rewrite ShowExceptions::render_exeption_with_template to re-raise the exception in case of certain errors (e.g. 500 and not 404)? Regards, Kedar> --Matt Jones >-- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To post to this group, send email to rubyonrails-talk-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org To unsubscribe from this group, send email to rubyonrails-talk+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org To view this discussion on the web visit https://groups.google.com/d/msg/rubyonrails-talk/-/tFJFA3JTql4J. For more options, visit https://groups.google.com/groups/opt_out.