From 14c6e828820073da658eb39f61d17d1f3cbdb3aa Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Oliver=20G=C3=BCnther?= <mail@oliverguenther.de>
Date: Tue, 22 Jan 2019 13:33:18 +0100
Subject: [PATCH] Create error handler and helper for streaming to multiple
 receivers

---
 app/controllers/application_controller.rb |  1 +
 app/helpers/open_project_error_helper.rb  | 35 ++++++++++
 lib/open_project.rb                       | 11 +++
 lib/open_project/logging/log_delegator.rb | 82 +++++++++++++++++++++++
 4 files changed, 129 insertions(+)
 create mode 100644 app/helpers/open_project_error_helper.rb
 create mode 100644 lib/open_project/logging/log_delegator.rb

diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index 5206578617f..d39ab3eca4d 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -44,6 +44,7 @@ class ApplicationController < ActionController::Base
   include HookHelper
   include ::OpenProject::Authentication::SessionExpiry
   include AdditionalUrlHelpers
+  include OpenProjectErrorHelper
 
   layout 'base'
 
diff --git a/app/helpers/open_project_error_helper.rb b/app/helpers/open_project_error_helper.rb
new file mode 100644
index 00000000000..a427368ebda
--- /dev/null
+++ b/app/helpers/open_project_error_helper.rb
@@ -0,0 +1,35 @@
+##
+# Logging helper to forward to the OpenProject log delegator
+# which will log and report errors appropriately.
+module OpenProjectErrorHelper
+  def op_logger
+    ::OpenProject.logger
+  end
+
+  def op_handle_error(message_or_exception, context = {})
+    ::OpenProject.logger.error message_or_exception, context.merge(op_logging_context)
+  end
+
+  def op_handle_warning(message_or_exception, context = {})
+    ::OpenProject.logger.warn message_or_exception, context.merge(op_logging_context)
+  end
+
+  def op_handle_info(message_or_exception, context = {})
+    ::OpenProject.logger.info message_or_exception, context.merge(op_logging_context)
+  end
+
+  def op_handle_debug(message_or_exception, context = {})
+    ::OpenProject.logger.debug message_or_exception, context.merge(op_logging_context)
+  end
+
+  private
+
+  def op_logging_context
+    {
+      current_user: current_user,
+      params: params,
+      request: try(:request),
+      env: try(:env),
+    }
+  end
+end
diff --git a/lib/open_project.rb b/lib/open_project.rb
index efdabdf7ad3..9c06d2d17bd 100644
--- a/lib/open_project.rb
+++ b/lib/open_project.rb
@@ -32,6 +32,7 @@ require 'redmine/menu_manager'
 require 'redmine/activity'
 require 'redmine/search'
 require 'open_project/custom_field_format'
+require 'open_project/logging/log_delegator'
 require 'redmine/mime_type'
 require 'redmine/core_ext'
 require 'open_project/design'
@@ -41,3 +42,13 @@ require 'redmine/plugin'
 require 'redmine/notifiable'
 
 require 'csv'
+
+module OpenProject
+
+  ##
+  # Shortcut to the OpenProject log delegator, which extends
+  # default Rails error handling with other error handlers such as sentry.
+  def self.logger
+    ::OpenProject::Logging::LogDelegator
+  end
+end
diff --git a/lib/open_project/logging/log_delegator.rb b/lib/open_project/logging/log_delegator.rb
new file mode 100644
index 00000000000..35da3bc08d1
--- /dev/null
+++ b/lib/open_project/logging/log_delegator.rb
@@ -0,0 +1,82 @@
+module OpenProject
+  module Logging
+    class LogDelegator
+      class << self
+
+        ##
+        # Consume a message and let it be handled
+        # by all handlers
+        def log(exception, context = {})
+          message =
+            if exception.is_a? Exception
+              context[:exception] = exception
+              context[:backtrace] = clean_backtrace(exception)
+              message = "#{exception}: #{exception.message}"
+            else
+              exception.to_s
+            end
+
+          # Set current contexts
+          context[:level] ||= context[:exception] ? :error : :info
+          context[:current_user] ||= User.current
+
+          registered_handlers.each do |handler|
+            handler.call message, context
+          end
+
+          nil
+        end
+
+        %i(debug info warn error fatal unknown).each do |level|
+          define_method(level) do |*args|
+            message = args.shift
+            context = args.shift || {}
+
+            log(message, context.merge(level: level))
+          end
+        end
+
+        ##
+        # Get a clean backtrace
+        def clean_backtrace(exception)
+          return nil unless exception&.backtrace
+          Rails.backtrace_cleaner.clean exception.backtrace
+        end
+
+        ##
+        # The active set of error handlers
+        def registered_handlers
+          @handlers ||= default_handlers
+        end
+
+        private
+
+        def default_handlers
+          [method(:rails_logger_handler)]
+        end
+
+        ##
+        # A lambda handler for logging the error
+        # to rails.
+        def rails_logger_handler(message, context = {})
+          Rails.logger.public_send(
+            context[:level],
+            message + context_string(context)
+          )
+
+          if backtrace = context[:backtrace]
+            Rails.logger.debug { backtrace.join($/) }
+          end
+        end
+
+        ##
+        # Create a context string
+        def context_string(context)
+          ''.tap do |str|
+            str << " [user=#{context[:user].id}]" if context[:user]
+          end
+        end
+      end
+    end
+  end
+end