Support TASK_IDLE process status. Include IDLE process in UNINTERRUPTIBLE metric for backward compatibility. Add new option to separate out metric if desired

[awangptc]

Pull Request Checklist

Is this in reference to an existing issue?
#65

General

• Update Changelog following the conventions laid out here

• [N/A] Update README with any necessary configuration snippets

• [N/A] Binstubs are created if needed

• RuboCop passes

• Existing tests pass

New Plugins

• Tests

• Add the plugin to the README

• Does it have a complete header as outlined here

Purpose

Support new changes to process state in kernel 4.14+

Known Compatibility Issues

[awangptc]

Automated spec tests were added but also ran some manual tests to confirm:

$ /opt/sensu/embedded/bin/metrics-processes-threads-count.rb -t -S
host.system.process_count 89 1525299474
host.system.thread_count 244 1525299474
host.system.sleeping 61 1525299474
host.system.running 1 1525299474
host.system.ininterruptible_sleep 27 1525299474   <--- 27 uninterruptible sleep processes
host.system.stopped 0 1525299474
host.system.stopped_by_debugger 0 1525299474
host.system.dead 0 1525299474
host.system.zombie 0 1525299474

$ /opt/sensu/embedded/bin/metrics-processes-threads-count.rb -t -S -I
host.system.process_count 89 1525299481
host.system.thread_count 244 1525299481
host.system.sleeping 61 1525299481
host.system.running 1 1525299481
host.system.ininterruptible_sleep 0 1525299481 <--- 0 uninterruptible sleep processes
host.system.stopped 0 1525299481
host.system.stopped_by_debugger 0 1525299481
host.system.dead 0 1525299481
host.system.zombie 0 1525299481
host.system.idle 27 1525299481 <--- 27 idle processes

Both results were to be expected since there are no uninterruptible sleeping processes

[majormoses]

LGTM

Thanks for taking the time to talk this out on slack.

[majormoses]

released: https://rubygems.org/gems/sensu-plugins-process-checks/versions/3.2.0