Exception Notification

THIS README IS FOR THE MASTER BRANCH AND REFLECTS THE WORK CURRENTLY EXISTING ON THE MASTER BRANCH. IF YOU ARE WISHING TO USE A NON-MASTER BRANCH OF EXCEPTION NOTIFICATION, PLEASE CONSULT THAT BRANCH'S README AND NOT THIS ONE.

The Exception Notification gem provides a set of notifiers for sending notifications when errors occur in a Rack/Rails application. The built-in notifiers can deliver notifications by email, Campfire, HipChat, Slack, IRC or via custom WebHooks.

There's a great Railscast about Exception Notification you can see that may help you getting started.

Requirements

Ruby 2.0 or greater
Rails 4.0 or greater, Sinatra or another Rack-based application.

For previous releases, please checkout this.

Getting Started

Add the following line to your application's Gemfile:

gem 'exception_notification'

Rails

ExceptionNotification is used as a rack middleware, or in the environment you want it to run. In most cases you would want ExceptionNotification to run on production. Thus, you can make it work by putting the following lines in your config/environments/production.rb:

Rails.application.config.middleware.use ExceptionNotification::Rack,
  :email => {
    :email_prefix => "[PREFIX] ",
    :sender_address => %{"notifier" <[email protected]>},
    :exception_recipients => %w{[email protected]}
  }

Note: In order to enable delivery notifications by email make sure you have ActionMailer configured.

Rack/Sinatra

In order to use ExceptionNotification with Sinatra, please take a look in the example application.

Notifiers

ExceptionNotification relies on notifiers to deliver notifications when errors occur in your applications. By default, six notifiers are available:

Campfire notifier
Email notifier
HipChat notifier
IRC notifier
Slack notifier
WebHook notifier

But, you also can easily implement your own custom notifier.

Campfire notifier

This notifier sends notifications to your Campfire room.

Usage

Just add the tinder gem to your Gemfile:

gem 'tinder'

To configure it, you need to set the subdomain, token and room_name options, like this:

Rails.application.config.middleware.use ExceptionNotification::Rack,
  :email => {
    :email_prefix => "[PREFIX] ",
    :sender_address => %{"notifier" <[email protected]>},
    :exception_recipients => %w{[email protected]}
  },
  :campfire => {
    :subdomain => 'my_subdomain',
    :token => 'my_token',
    :room_name => 'my_room'
  }

Options

subdomain

String, required

Your subdomain at Campfire.

room_name

String, required

The Campfire room where the notifications must be published to.

token

String, required

The API token to allow access to your Campfire account.

For more options to set Campfire, like ssl, check here.

Email notifier

The Email notifier sends notifications by email. The notifications/emails sent includes information about the current request, session, and environment, and also gives a backtrace of the exception.

After an exception notification has been delivered the rack environment variable exception_notifier.delivered will be set to true.

ActionMailer configuration

For the email to be sent, there must be a default ActionMailer delivery_method setting configured. If you do not have one, you can use the following code (assuming your app server machine has sendmail). Depending on the environment you want ExceptionNotification to run in, put the following code in your config/environments/production.rb and/or config/environments/development.rb:

config.action_mailer.delivery_method = :sendmail
# Defaults to:
# config.action_mailer.sendmail_settings = {
#   :location => '/usr/sbin/sendmail',
#   :arguments => '-i -t'
# }
config.action_mailer.perform_deliveries = true
config.action_mailer.raise_delivery_errors = true

Options

sender_address

String, default: %("Exception Notifier" [email protected])

Who the message is from.

exception_recipients

String/Array of strings, default: []

Who the message is destined for, can be a string of addresses, or an array of addresses.

email_prefix

String, default: [ERROR]

The subject's prefix of the message.

sections

Array of strings, default: %w(request session environment backtrace)

By default, the notification email includes four parts: request, session, environment, and backtrace (in that order). You can customize how each of those sections are rendered by placing a partial named for that part in your app/views/exception_notifier directory (e.g., _session.rhtml). Each partial has access to the following variables:

@kontroller     # the controller that caused the error
@request        # the current request object
@exception      # the exception that was raised
@backtrace      # a sanitized version of the exception's backtrace
@data           # a hash of optional data values that were passed to the notifier
@sections       # the array of sections to include in the email

You can reorder the sections, or exclude sections completely, by using sections option. You can even add new sections that describe application-specific data--just add the section's name to the list (wherever you'd like), and define the corresponding partial. Like the following example with two new added sections:

Rails.application.config.middleware.use ExceptionNotification::Rack,
  :email => {
    :email_prefix => "[PREFIX] ",
    :sender_address => %{"notifier" <[email protected]>},
    :exception_recipients => %w{[email protected]},
    :sections => %w{my_section1 my_section2}
  }

Place your custom sections under ./app/views/exception_notifier/ with the suffix .text.erb, e.g. ./app/views/exception_notifier/_my_section1.text.erb.

If your new section requires information that isn't available by default, make sure it is made available to the email using the exception_data macro:

class ApplicationController < ActionController::Base
  before_filter :log_additional_data
  ...
  protected
    def log_additional_data
      request.env["exception_notifier.exception_data"] = {
        :document => @document,
        :person => @person
      }
    end
  ...
end

In the above case, @document and @person would be made available to the email renderer, allowing your new section(s) to access and display them. See the existing sections defined by the plugin for examples of how to write your own.

background_sections

Array of strings, default: %w(backtrace data)

When using background notifications some variables are not available in the views, like @kontroller and @request. Thus, you may want to include different sections for background notifications:

Rails.application.config.middleware.use ExceptionNotification::Rack,
  :email => {
    :email_prefix => "[PREFIX] ",
    :sender_address => %{"notifier" <[email protected]>},
    :exception_recipients => %w{[email protected]},
    :background_sections => %w{my_section1 my_section2 backtrace data}
  }

email_headers

Hash of strings, default: {}

Additionally, you may want to set customized headers on the outcoming emails. To do so, simply use the :email_headers option:

Rails.application.config.middleware.use ExceptionNotification::Rack,
  :email => {
    :email_prefix         => "[PREFIX] ",
    :sender_address       => %{"notifier" <[email protected]>},
    :exception_recipients => %w{[email protected]},
    :email_headers        => { "X-Custom-Header" => "foobar" }
  }

verbose_subject

Boolean, default: true

If enabled, include the exception message in the subject. Use :verbose_subject => false to exclude it.

normalize_subject

Boolean, default: false

If enabled, remove numbers from subject so they thread as a single one. Use :normalize_subject => true to enable it.

email_format

Symbol, default: :text

By default, ExceptionNotification sends emails in plain text, in order to sends multipart notifications (aka HTML emails) use :email_format => :html.

delivery_method

Symbol, default: :smtp

By default, ExceptionNotification sends emails using the ActionMailer configuration of the application. In order to send emails by another delivery method, use the delivery_method option:

Rails.application.config.middleware.use ExceptionNotification::Rack,
  :email => {
    :email_prefix         => "[PREFIX] ",
    :sender_address       => %{"notifier" <[email protected]>},
    :exception_recipients => %w{[email protected]},
    :delivery_method => :postmark,
    :postmark_settings => {
      :api_key => ENV["POSTMARK_API_KEY"]
    }
  }

Besides the delivery_method option, you also can customize the mailer settings by passing a hash under an option named DELIVERY_METHOD_settings. Thus, you can use override specific SMTP settings for notifications using:

Rails.application.config.middleware.use ExceptionNotification::Rack,
  :email => {
    :email_prefix         => "[PREFIX] ",
    :sender_address       => %{"notifier" <[email protected]>},
    :exception_recipients => %w{[email protected]},
    :delivery_method => :smtp,
    :smtp_settings => {
      :user_name => "bob",
      :password => "password",
    }
  }

A complete list of smtp_settings options can be found in the ActionMailer Configuration documentation.

mailer_parent

String, default: ActionMailer::Base

The parent mailer which ExceptionNotification mailer inherit from.

deliver_with

*Symbol, default: :deliver_now

The method name to send emalis using ActionMailer.

HipChat notifier

This notifier sends notifications to your Hipchat room.

Usage

Just add the hipchat gem to your Gemfile:

gem 'hipchat'

To configure it, you need to set the token and room_name options, like this:

Rails.application.config.middleware.use ExceptionNotification::Rack,
  :email => {
    :email_prefix => "[PREFIX] ",
    :sender_address => %{"notifier" <[email protected]>},
    :exception_recipients => %w{[email protected]}
  },
  :hipchat => {
    :api_token => 'my_token',
    :room_name => 'my_room'
  }

Options

room_name

String, required

The HipChat room where the notifications must be published to.

api_token

String, required

The API token to allow access to your HipChat account.

notify

Boolean, optional

Notify users. Default : false.

color

String, optional

Color of the message. Default : 'red'.

from

String, optional, maximum length : 15

Message will appear from this nickname. Default : 'Exception'.

For all options & possible values see Hipchat API.

IRC notifier

This notifier sends notifications to an IRC channel using the carrier-pigeon gem.

Usage

Just add the carrier-pigeon gem to your Gemfile:

gem 'carrier-pigeon'

To configure it, you need to set at least the 'domain' option, like this:

Rails.application.config.middleware.use ExceptionNotification::Rack,
  :email => {
    :email_prefix => "[PREFIX] ",
    :sender_address => %{"notifier" <[email protected]>},
    :exception_recipients => %w{[email protected]}
  },
  :irc => {
    :domain => 'irc.example.com'
  }

There are several other options, which are described below. For example, to use ssl and a password, add a prefix, post to the '#log' channel, and include recipients in the message (so that they will be notified), your configuration might look like this:

Rails.application.config.middleware.use ExceptionNotification::Rack,
  :irc => {
    :domain => 'irc.example.com',
    :nick => 'BadNewsBot',
    :password => 'secret',
    :port => 6697,
    :channel => '#log',
    :ssl => true,
    :prefix => '[Exception Notification]',
    :recipients => ['peter', 'michael', 'samir']
  }

Options

domain

String, required

The domain name of your IRC server.

nick

String, optional

The message will appear from this nick. Default : 'ExceptionNotifierBot'.

password

String, optional

Password for your IRC server.

port

String, optional

Port your IRC server is listening on. Default : 6667.

channel

String, optional

Message will appear in this channel. Default : '#log'.

notice

Boolean, optional

Send a notice. Default : false.

ssl

Boolean, optional

Whether to use SSL. Default : false.

join

Boolean, optional

Join a channel. Default : false.

recipients

Array of strings, optional

Nicks to include in the message. Default: []

Slack notifier

This notifier sends notifications to a slack channel using the slack-notifier gem.

Usage

Just add the slack-notifier gem to your Gemfile:

gem 'slack-notifier'

To configure it, you need to set at least the 'webhook_url' option, like this:

Rails.application.config.middleware.use ExceptionNotification::Rack,
  :email => {
    :email_prefix => "[PREFIX] ",
    :sender_address => %{"notifier" <[email protected]>},
    :exception_recipients => %w{[email protected]}
  },
  :slack => {
    :webhook_url => "[Your webhook url]",
    :channel => "#exceptions",
    :additional_parameters => {
      :icon_url => "http://image.jpg",
      :mrkdwn => true
    }
  }

The slack notification will include any data saved under env["exception_notifier.exception_data"]. If you find this too verbose, you can determine to exclude certain information by doing the following:

Rails.application.config.middleware.use ExceptionNotification::Rack,
  :slack => {
    :webhook_url => "[Your webhook url]",
    :channel => "#exceptions",
    :additional_parameters => {
      :icon_url => "http://image.jpg",
      :mrkdwn => true
    },
    :ignore_data_if => lambda {|key, value|
      "#{key}" == 'key_to_ignore' || value.is_a?(ClassToBeIgnored)
    }
  }

Any evaluation to true will cause the key / value pair not be be sent along to Slack.

Options

webhook_url

String, required

The Incoming WebHook URL on slack.

channel

String, optional

Message will appear in this channel. Defaults to the channel you set as such on slack.

username

String, optional

Username of the bot. Defaults to the name you set as such on slack

custom_hook

String, optional

Custom hook name. See slack-notifier for more information. Default: 'incoming-webhook'

additional_parameters

Hash of strings, optional

Contains additional payload for a message (e.g avatar, attachments, etc). See slack-notifier for more information.. Default: '{}'

WebHook notifier

This notifier ships notifications over the HTTP protocol.

Usage

Just add the HTTParty gem to your Gemfile:

gem 'httparty'

To configure it, you need to set the url option, like this:

Rails.application.config.middleware.use ExceptionNotification::Rack,
  :email => {
    :email_prefix => "[PREFIX] ",
    :sender_address => %{"notifier" <[email protected]>},
    :exception_recipients => %w{[email protected]}
  },
  :webhook => {
    :url => 'http://domain.com:5555/hubot/path'
  }

By default, the WebhookNotifier will call the URLs using the POST method. But, you can change this using the http_method option.

Rails.application.config.middleware.use ExceptionNotification::Rack,
  :email => {
    :email_prefix => "[PREFIX] ",
    :sender_address => %{"notifier" <[email protected]>},
    :exception_recipients => %w{[email protected]}
  },
  :webhook => {
    :url => 'http://domain.com:5555/hubot/path',
    :http_method => :get
  }

Besides the url and http_method options, all the other options are passed directly to HTTParty. Thus, if the HTTP server requires authentication, you can include the following options:

Rails.application.config.middleware.use ExceptionNotification::Rack,
  :email => {
    :email_prefix => "[PREFIX] ",
    :sender_address => %{"notifier" <[email protected]>},
    :exception_recipients => %w{[email protected]}
  },
  :webhook => {
    :url => 'http://domain.com:5555/hubot/path',
    :basic_auth => {
      :username => 'alice',
      :password => 'password'
    }
  }

For more HTTParty options, check out the documentation.

Custom notifier

Simply put, notifiers are objects which respond to #call(exception, options) method. Thus, a lambda can be used as a notifier as follow:

ExceptionNotifier.add_notifier :custom_notifier_name,
  ->(exception, options) { puts "Something goes wrong: #{exception.message}"}

More advanced users or third-party framework developers, also can create notifiers to be shipped in gems and take advantage of ExceptionNotification's Notifier API to standardize the various solutions out there. For this, beyond the #call(exception, options) method, the notifier class MUST BE defined under the ExceptionNotifier namespace and its name sufixed by Notifier, e.g: ExceptionNotifier::SimpleNotifier.

Example

Define the custom notifier:

module ExceptionNotifier
  class SimpleNotifier
    def initialize(options)
      # do something with the options...
    end

    def call(exception, options={})
      # send the notification
    end
  end
end

Using it:

Rails.application.config.middleware.use ExceptionNotification::Rack,
  :email => {
    :email_prefix => "[PREFIX] ",
    :sender_address => %{"notifier" <[email protected]>},
    :exception_recipients => %w{[email protected]}
  },
  :simple => {
    # simple notifier options
  }

Ignore Exceptions

You can choose to ignore certain exceptions, which will make ExceptionNotification avoid sending notifications for those specified. There are three ways of specifying which exceptions to ignore:

:ignore_exceptions - By exception class (i.e. ignore RecordNotFound ones)
:ignore_crawlers - From crawler (i.e. ignore ones originated by Googlebot)
:ignore_if - Custom (i.e. ignore exceptions that satisfy some condition)

:ignore_exceptions

Array of strings, default: %wAbstractController::ActionNotFound ActionController::RoutingError ActionController::UnknownFormat

Ignore specified exception types. To achieve that, you should use the :ignore_exceptions option, like this:

Rails.application.config.middleware.use ExceptionNotification::Rack,
  :ignore_exceptions => ['ActionView::TemplateError'] + ExceptionNotifier.ignored_exceptions,
  :email => {
    :email_prefix         => "[PREFIX] ",
    :sender_address       => %{"notifier" <[email protected]>},
    :exception_recipients => %w{[email protected]}
  }

The above will make ExceptionNotifier ignore a TemplateError exception, plus the ones ignored by default.

:ignore_crawlers

Array of strings, default: []

In some cases you may want to avoid getting notifications from exceptions made by crawlers. To prevent sending those unwanted notifications, use the :ignore_crawlers option like this:

Rails.application.config.middleware.use ExceptionNotification::Rack,
  :ignore_crawlers => %w{Googlebot bingbot},
  :email => {
    :email_prefix         => "[PREFIX] ",
    :sender_address       => %{"notifier" <[email protected]>},
    :exception_recipients => %w{[email protected]}
  }

:ignore_if

Lambda, default: nil

Last but not least, you can ignore exceptions based on a condition. Take a look:

Rails.application.config.middleware.use ExceptionNotification::Rack,
  :ignore_if => ->(env, exception) { exception.message =~ /^Couldn't find Page with ID=/ },
  :email => {
    :email_prefix         => "[PREFIX] ",
    :sender_address       => %{"notifier" <[email protected]>},
    :exception_recipients => %w{[email protected]},
  }

You can make use of both the environment and the exception inside the lambda to decide wether to avoid or not sending the notification.

Rack X-Cascade Header

Some rack apps (Rails in particular) utilize the "X-Cascade" header to pass the request-handling responsibility to the next middleware in the stack.

Rails' routing middleware uses this strategy, rather than raising an exception, to handle routing errors (e.g. 404s); to be notified whenever a 404 occurs, set this option to "false."

:ignore_cascade_pass

Boolean, default: true

Set to false to trigger notifications when another rack middleware sets the "X-Cascade" header to "pass."

Background Notifications

If you want to send notifications from a background process like DelayedJob, you should use the notify_exception method like this:

begin
  some code...
rescue => e
  ExceptionNotifier.notify_exception(e)
end

You can include information about the background process that created the error by including a data parameter:

begin
  some code...
rescue => exception
  ExceptionNotifier.notify_exception(exception,
    :data => {:worker => worker.to_s, :queue => queue, :payload => payload})
end

Manually notify of exception

If your controller action manually handles an error, the notifier will never be run. To manually notify of an error you can do something like the following:

rescue_from Exception, :with => :server_error

def server_error(exception)
  # Whatever code that handles the exception

  ExceptionNotifier.notify_exception(exception,
    :env => request.env, :data => {:message => "was doing something wrong"})
end

Extras

Rails

Since his first version, ExceptionNotification was just a simple rack middleware. But, the version 4.0.0 introduced the option to use it as a Rails engine. In order to use ExceptionNotification as an engine, just run the following command from the terminal:

rails g exception_notification:install

This command generates an initialize file (config/initializers/exception_notification.rb) where you can customize your configurations.

Resque/Sidekiq

Instead of manually calling background notifications foreach job/worker, you can configure ExceptionNotification to do this automatically. For this, run:

rails g exception_notification:install --resque

rails g exception_notification:install --sidekiq

Versions

For v4.0.1, see this tag:

http://github.com/smartinez87/exception_notification/tree/v4.0.1

For v4.0.0, see this tag:

http://github.com/smartinez87/exception_notification/tree/v4.0.0

For v3.0.1, see this tag:

http://github.com/smartinez87/exception_notification/tree/v3.0.1

For v3.0.0, see this tag:

http://github.com/smartinez87/exception_notification/tree/v3.0.0

For previous releases, visit:

https://github.com/smartinez87/exception_notification/tags

If you are running Rails 2.3 then see the branch for that:

http://github.com/smartinez87/exception_notification/tree/2-3-stable

If you are running pre-rack Rails then see this tag:

http://github.com/smartinez87/exception_notification/tree/pre-2-3

Support and tickets

Here's the list of issues we're currently working on.

To contribute, please read first the Contributing Guide.

Exception Notification

Requirements

Getting Started

Rails

Rack/Sinatra

Notifiers

Campfire notifier

Usage

Options

subdomain

room_name

token

Email notifier

ActionMailer configuration

Options

sender_address

exception_recipients

email_prefix

sections

background_sections

email_headers

verbose_subject

normalize_subject

email_format

delivery_method

mailer_parent

deliver_with

HipChat notifier

Usage

Options

room_name

api_token

notify

color

from

IRC notifier

Usage

Options

domain

nick

password

port

channel

notice

ssl

join

recipients

Slack notifier

Usage

Options

webhook_url

channel

username

custom_hook

additional_parameters

WebHook notifier

Usage

Custom notifier

Example

Ignore Exceptions

:ignore_exceptions

:ignore_crawlers

:ignore_if

Rack X-Cascade Header

:ignore_cascade_pass

Background Notifications

Manually notify of exception

Extras

Rails

Resque/Sidekiq

Versions

Support and tickets

License