Custom report handler runs multiple times

Chef Infra (archive)
1

Hi - I created a very simple report handler, which works but runs multiple times via the chef-client daemon. It appears to run once for each successful chef-client run. If I tail the log and wait or send a USR1 signal to the chef-client process to force a run I will see one more report_handler log line than the time before. I have tested the config below on chef-client 16.10.17

The top of my client.rb is as follows:

require "/etc/chef/testthingy_handler.rb"
report_handlers << Chef::Handler::TestThingy.new

The testtingy_handler.rb file as the following:

require 'chef/handler'

class Chef
  class Handler
    class TestThingy < Chef::Handler
      def report
      end
    end
  end
end

Yes, right now the report function does nothing, I have added something simple to make sure it wasn't that. After adding the above, restarting chef-client and waiting until two runs have completed I will see the following at the bottom of the log.

INFO: Running report handlers
  - Chef::Handler::TestThingy
  - Chef::Handler::TestThingy
Running handlers complete
INFO: Report handlers complete

When a third run completes another '- Chef::Handler::TestThingy' line will join the two above and so on until there are many. Only restarting the daemon resets it. Does anyone know why this might be? Am I creating the handler incorrectly? Is there anything you can suggest to debug the issue?

Thanks for reading.

2

The client.rb is getting parsed by the daemon every time and this line is appending yet another handler every single time:

report_handlers << Chef::Handler::TestThingy.new

This is then forked off to the child process which "inherits" the ever-extending config.

We don't recommend using the daemon process at all now. It is generally better to use systemd timers, or a scheduled task or just run one shot chef-client runs out of cron. It causes issues like this and will also cause problems on upgrades where the daemon is often left un-upgraded by the chef_client_updater cookbook.

To fix it in the short term just setting it rather than appending it will probably work:

report_handlers [ Chef::Handler::TestThingy.new ]

Otherwise:

report_handlers << Chef::Handler::TestThingy.new
  unless report_handlers.any? { |x| x.is_a?(Chef::Handler::TestThingy) }

or something like that.

1 Like
3

Thank you for the explanation and example fixes. It gives me a couple of options moving forward.