[receiver/elasticsearch] Add additional metrics

[davidji99]

Description:
Adding a few more metrics to the elasticsearch receiver.

Please let me know what I missed. This is my first contribution. Thank you.

Documentation:
The documentation was auto-added when running go generate ./...

TODO:

• Add tests

[linux-foundation-easycla]

The committers listed above are authorized under a signed CLA.

• ✅ login: davidji99 / name: DJ (e7faf1c, a76d481, 7797176, 4eb1578, 90d8e65)

[davidji99]

@jkowall Any particular reason for thumbs downing this draft PR?

[jkowall]

@jkowall Any particular reason for thumbs downing this draft PR?

Nope, meant to thumbs up! Good contribution.

[djaglowski]

Thanks for the contribution @davidji99.

Typically, please open an issue proposing the changes you'd like to see.

Overall this looks good to me, but there are quite a few minor details to work through.

I'd also like to see these metrics represented in the results of scraper_test.go and integration_test.go, or understand why not.

[davidji99]

Thanks for the contribution @davidji99.

Typically, please open an issue proposing the changes you'd like to see.

Overall this looks good to me, but there are quite a few minor details to work through.

I'd also like to see these metrics represented in the results of scraper_test.go and integration_test.go, or understand why not.

Thanks for the review! I will work through your proposed changes.

Yes, I plan on adding these new metrics to the relevant _test.go files.

[davidji99]

Hi @djaglowski,

I've updated receiver/elasticsearchreceiver/testdata/sample_payloads/nodes_linux.json and receiver/elasticsearchreceiver/testdata/expected_metrics/full.json to incorporate the new metrics. However, when running the TestScraper test, I consistently get:

=== CONT  TestScraper
    scraper_test.go:61:
        	Error Trace:	/Users/david.ji/dev_exclusions/opentelemetry-collector-contrib/receiver/elasticsearchreceiver/scraper_test.go:61
        	Error:      	Received unexpected error:
        	            	number of metrics does not match expected: 41, actual: 32

Maybe I'm missing something here but I expected the metric count to be the same?

[djaglowski]

My suggestion for updating the expected metric json files is to temporarily insert a golden.WriteMetrics(expectedFile, actualMetrics) call in the test code. This will overwrite the expected file with the metrics you actually get from the scraper. Then, take a close look at the diff and see if it makes sense at that point.

[davidji99]

Thank you for the tip @djaglowski. I've updated this PR with passing tests. Could you take another look?

[davidji99]

@djaglowski Updated the PR. Can you re-run tests?

[djaglowski]

Thanks for the contribution @davidji99!

[davidji99]

Thank you for your help and patience @djaglowski !