Add IO operations in progress to be exported in diskio module

[VertexC]

What does this PR do?

Add io.ops in fields exported by system.diskio in metricbeat.

Why is it important?

As #20691 points out, we may need to calculate the queue time based on this new field system.diskio.io.ops.

Checklist

- [ ] I have commented my code, particularly in hard-to-understand areas
- [ ] I have made corresponding changes to the documentation

• My code follows the style guidelines of this project
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.

Related issues

• Closes [metricbeat] Add IopsInProgress metric in the list of exported fields for diskio system module #20691

[elasticmachine]

Since this is a community submitted pull request, a Jenkins build has not been kicked off automatically. Can an Elastic organization member please verify the contents of this patch and then kick off a build manually?

[elasticmachine]

Since this is a community submitted pull request, a Jenkins build has not been kicked off automatically. Can an Elastic organization member please verify the contents of this patch and then kick off a build manually?

[cla-checker-service]

💚 CLA has been signed

[VertexC]

@andresrc @unixsurfer Could you kindly review this PR?

[elasticmachine]

💚 Build Succeeded

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Build stats

• Build Cause: [Started by user Alex K., Replayed #13]

• Start Time: 2020-11-23T16:35:39.187+0000

• Duration: 62 min 55 sec

Test stats 🧪

Test	Results
Failed	0
Passed	2254
Skipped	522
Total	2776

💚 Flaky test report

Tests succeeded.

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Test stats 🧪

Test	Results
Failed	0
Passed	2254
Skipped	522
Total	2776

[elasticmachine]

Pinging @elastic/integrations-services (Team:Services)

[unixsurfer]

@VertexC I am sorry but I'm not familiar with the development of metricbeats and therefore I can't perform a proper review.
I would like to thank you for taking the time to add support for IO operations in progress metric.

[VertexC]

@VertexC I am sorry but I'm not familiar with the development of metricbeats and therefore I can't perform a proper review.
I would like to thank you for taking the time to add support for IO operations in progress metric.

It is okay :) And thanks for posting this good-for-first issue.

[VertexC]

The diskio_linux fails in CI due to timeout issue. I only have mac (unix) environment and relevant tests might just skip locally. Do you have any idea on this timeout error? @fearful-symmetry

=================================== FAILURES ===================================
____________________________ Test.test_diskio_linux ____________________________
self = <test_system.Test testMethod=test_diskio_linux>
    @unittest.skipUnless(re.match("(?i)linux", sys.platform), "os")
    def test_diskio_linux(self):
        """
        Test system/diskio output on linux.
        """
        self.render_config_template(modules=[{
            "name": "system",
            "metricsets": ["diskio"],
            "period": "5s"
        }])
        proc = self.start_beat()
>       self.wait_until(lambda: self.output_lines() > 0)
module/system/test_system.py:251: 
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ 
self = <test_system.Test testMethod=test_diskio_linux>
cond = <function Test.test_diskio_linux.<locals>.<lambda> at 0x7f9365a1f510>
max_timeout = 10, poll_interval = 0.1, name = 'cond'
    def wait_until(self, cond, max_timeout=10, poll_interval=0.1, name="cond"):
        """
        Waits until the cond function returns true,
        or until the max_timeout is reached. Calls the cond
        function every poll_interval seconds.
    
        If the max_timeout is reached before cond() returns
        true, an exception is raised.
        """
        start = datetime.now()
        while not cond():
            if datetime.now() - start > timedelta(seconds=max_timeout):
                raise TimeoutError("Timeout waiting for '{}' to be true. ".format(name) +
>                                  "Waited {} seconds.".format(max_timeout))
E               beat.beat.TimeoutError: Timeout waiting for 'cond' to be true. Waited 10 seconds.
../libbeat/tests/system/beat/beat.py:363: TimeoutError

[fearful-symmetry]

Not sure, I imagine it's a deeper failure that the CI is just reporting as a timeout.

[fearful-symmetry]

Not sure why we're running into CI issues here....

[fearful-symmetry]

jenkins, test this

[elasticmachine]

💚 Flaky test report

Tests succeeded.

Expand to view the summary

Test stats 🧪

Test	Results
Failed	0
Passed	2248
Skipped	508
Total	2756

[VertexC]

@fearful-symmetry Hi, do you have any plan to merge this pr? I'm happy to merge from master and rebuild fields, but if it is not merged for certain time, new conflicts will occur.

[fearful-symmetry]

Hey, sorry about dropping this last week. We're good to go, it looks like. Just rebase the PR and I can approve it. @VertexC

[fearful-symmetry]

jenkins, test this

[VertexC]

It looks like Lint is somehow blocked. Shall I force push again? @fearful-symmetry

[fearful-symmetry]

Try to merge from master again, yah. Not sure why the CI is blocked now.

[fearful-symmetry]

jenkins, test this

[fearful-symmetry]

@VertexC while I fight with CI, one last thing: Can you add a changelog entry to CHANGELOG.next.asciidoc ?

[VertexC]

@VertexC while I fight with CI, one last thing: Can you add a changelog entry to CHANGELOG.next.asciidoc ?

Done :)

[fearful-symmetry]

jenkins, test this

[andresrc]

@fearful-symmetry does this need a backport?