Class: Chef::Handler

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Defined in:
lib/chef/handler.rb,
lib/chef/handler/json_file.rb,
lib/chef/handler/slow_report.rb,
lib/chef/handler/error_report.rb

Overview

The base class for an Exception or Notification Handler. Create your own handler by subclassing Chef::Handler. When a Chef run fails with an uncaught Exception, Chef will set the +run_status+ on your handler and call +report+

Examples:

require 'net/smtp'

module MyOrg
  class OhNoes < Chef::Handler

    def report
      # Create the email message
      message  = "From: Your Name <[email protected]>\n"
      message << "To: Destination Address <[email protected]>\n"
      message << "Subject: Chef Run Failure\n"
      message << "Date: #{Time.now.rfc2822}\n\n"

      # The Node is available as +node+
      message << "Chef run failed on #{node.name}\n"
      # +run_status+ is a value object with all of the run status data
      message << "#{run_status.formatted_exception}\n"
      # Join the backtrace lines. Coerce to an array just in case.
      message << Array(backtrace).join("\n")

      # Send the email
      Net::SMTP.start('your.smtp.server', 25) do |smtp|
        smtp.send_message message, 'from@address', 'to@address'
      end
    end

  end
end

Direct Known Subclasses

ErrorReport, JsonFile, SlowReport

Defined Under Namespace

Classes: ErrorReport, JsonFile, SlowReport

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Instance Attribute Details

#run_status ⇒ Object (readonly)

The Chef::RunStatus object containing data about the Chef run.



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# File 'lib/chef/handler.rb', line 170

def run_status
  @run_status
end

Class Method Details

.exception_handlers ⇒ Object

The list of currently configured exception handlers



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# File 'lib/chef/handler.rb', line 143

def self.exception_handlers
  Array(Chef::Config[:exception_handlers])
end

.handler_for(*args) ⇒ Object

FIXME: Chef::Handler should probably inherit from EventDispatch::Base and should wire up to those events rather than the "notifications" system which is hanging off of Chef::Client. Those "notifications" could then be deprecated in favor of events, and this class could become decoupled from the Chef::Client object.



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# File 'lib/chef/handler.rb', line 64

def self.handler_for(*args)
  if args.include?(:start)
    Chef::Config[:start_handlers] ||= []
    Chef::Config[:start_handlers] |= [self]
  end
  if args.include?(:report)
    Chef::Config[:report_handlers] ||= []
    Chef::Config[:report_handlers] |= [self]
  end
  if args.include?(:exception)
    Chef::Config[:exception_handlers] ||= []
    Chef::Config[:exception_handlers] |= [self]
  end
end

.report_handlers ⇒ Object

The list of currently configured report handlers



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# File 'lib/chef/handler.rb', line 117

def self.report_handlers
  Array(Chef::Config[:report_handlers])
end

.resolve_handler_instance(handler) ⇒ Object 



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# File 'lib/chef/handler.rb', line 84

def self.resolve_handler_instance(handler)
  if handler.is_a?(Class)
    if handler.respond_to?(:instance)
      # support retrieving a Singleton reporting object
      handler.instance
    else
      # just a class with no way to insert data
      handler.new
    end
  else
    # the Chef::Config array contains an instance, not a class
    handler
  end
end

.run_exception_handlers(run_status) ⇒ Object

Run the exception handlers. Usually will be called by a notification from Chef::Client when the run fails.



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# File 'lib/chef/handler.rb', line 149

def self.run_exception_handlers(run_status)
  events = run_status.events
  events.handlers_start(exception_handlers.size)
  Chef::Log.error("Running exception handlers")
  exception_handlers.each do |handler|
    handler = resolve_handler_instance(handler)
    handler.run_report_safely(run_status)
    events.handler_executed(handler)
  end
  events.handlers_completed
  Chef::Log.error("Exception handlers complete")
end

.run_report_handlers(run_status) ⇒ Object

Run the report handlers. This will usually be called by a notification from Chef::Client



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# File 'lib/chef/handler.rb', line 123

def self.run_report_handlers(run_status)
  events = run_status.events
  events.handlers_start(report_handlers.size)
  Chef::Log.info("Running report handlers")
  report_handlers.each do |handler|
    handler = resolve_handler_instance(handler)
    handler.run_report_safely(run_status)
    events.handler_executed(handler)
  end
  events.handlers_completed
  Chef::Log.info("Report handlers complete")
end

.run_start_handlers(run_status) ⇒ Object

Run the start handlers. This will usually be called by a notification from Chef::Client



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# File 'lib/chef/handler.rb', line 101

def self.run_start_handlers(run_status)
  Chef::Log.info("Running start handlers")
  start_handlers.each do |handler|
    handler = resolve_handler_instance(handler)
    handler.run_report_safely(run_status)
  end
  Chef::Log.info("Start handlers complete.")
end

.start_handlers ⇒ Object

The list of currently configured start handlers



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# File 'lib/chef/handler.rb', line 80

def self.start_handlers
  Array(Chef::Config[:start_handlers])
end

Instance Method Details

#action_collection ⇒ Object 



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# File 'lib/chef/handler.rb', line 269

def action_collection
  @run_status.run_context.action_collection
end

#all_resources ⇒ Object 



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# File 'lib/chef/handler.rb', line 218

def all_resources
  @all_resources ||= action_collection&.filtered_collection(unprocessed: false)&.resources || []
end

#data ⇒ Object

Return the Hash representation of the run_status



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# File 'lib/chef/handler.rb', line 300

def data
  @run_status.to_h
end

#failed_resources ⇒ Object 



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# File 'lib/chef/handler.rb', line 236

def failed_resources
  @failed_resources ||= action_collection&.filtered_collection(updated: false, up_to_date: false, skipped: false, unprocessed: false)&.resources || []
end

#report ⇒ Object

The main entry point for report handling. Subclasses should override this method with their own report handling logic.



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# File 'lib/chef/handler.rb', line 275

def report; end

#run_report_safely(run_status) ⇒ Object

This method is part of a private API. You should avoid using this method if possible, as it may be removed or be changed in the future.

Runs the report handler, rescuing and logging any errors it may cause. This ensures that all handlers get a chance to run even if one fails. This method should not be overridden by subclasses unless you know what you're doing.



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# File 'lib/chef/handler.rb', line 283

def run_report_safely(run_status)
  run_report_unsafe(run_status)
rescue Exception => e
  Chef::Log.error("Report handler #{self.class.name} raised #{e.inspect}")
  Array(e.backtrace).each { |line| Chef::Log.error(line) }
ensure
  @run_status = nil
end

#run_report_unsafe(run_status) ⇒ Object

Runs the report handler without any error handling. This method should not be used directly except in testing.



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# File 'lib/chef/handler.rb', line 294

def run_report_unsafe(run_status)
  @run_status = run_status
  report
end

#skipped_resources ⇒ Object 



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# File 'lib/chef/handler.rb', line 242

def skipped_resources
  @skipped_resources ||= action_collection&.filtered_collection(updated: false, up_to_date: false, failed: false, unprocessed: false)&.resources || []
end

#unprocessed_resources ⇒ Object

Unprocessed resources are those which are left over in the outer recipe context when a run fails. Sub-resources of unprocessed resourced are impossible to capture because they would require processing the outer resource.



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# File 'lib/chef/handler.rb', line 252

def unprocessed_resources
  @unprocessed_resources ||= action_collection&.filtered_collection(updated: false, up_to_date: false, failed: false, skipped: false)&.resources || []
end

#up_to_date_resources ⇒ Object 



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# File 'lib/chef/handler.rb', line 230

def up_to_date_resources
  @up_to_date_resources ||= action_collection&.filtered_collection(updated: false, skipped: false, failed: false, unprocessed: false)&.resources || []
end

#updated_resources ⇒ Object 



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# File 'lib/chef/handler.rb', line 224

def updated_resources
  @updated_resources ||= action_collection&.filtered_collection(up_to_date: false, skipped: false, failed: false, unprocessed: false)&.resources || []
end