Added support for shards total count in Elasticsearch Module

[philippkahr]

Hi,

I just added the support for the shards_stats.total_count which can be nice for alerting, since a lot of shards on a single node can impact performance.

Question: if I fix it here, that means it is fixed for the Elastic Agent integration package as well?

GET /_nodes/_all/stats?filter_path=*.*.*.shard_stats.*

Retrieves:

{
  "nodes": {
    "NXSI_2XFQaC2HH7ZvdTJuQ": {
      "indices": {
        "shard_stats": {
          "total_count": 0
        }
      }
    },
    "36aFMv40QX6MBZ4u1DsCCQ": {
      "indices": {
        "shard_stats": {
          "total_count": 0
        }
      }
    },
    "g2N_KasgRkuBEvD529XfhQ": {
      "indices": {
        "shard_stats": {
          "total_count": 1753
        }
      }
    },
    "ObCmi3u1Rhiyp4JTosFXdw": {
      "indices": {
        "shard_stats": {
          "total_count": 866
        }
      }
    },
    "AW982puiTbq-RNJpg23QEw": {
      "indices": {
        "shard_stats": {
          "total_count": 866
        }
      }
    }
  }
}

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• 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.

[mergify]

This pull request does not have a backport label.
If this is a bug or security fix, could you label this PR @philippkahr? 🙏.
For such, you'll need to label your PR with:

• The upcoming major version of the Elastic Stack
• The upcoming minor version of the Elastic Stack (if you're not pushing a breaking change)

To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-v8./d.0 is the label to automatically backport to the 8./d branch. /d is the digit

[elasticmachine]

💚 Build Succeeded

the below badges are clickable and redirect to their specific view in the CI or DOCS

Expand to view the summary

Build stats

• Duration: 50 min 33 sec

Test stats 🧪

Test	Results
Failed	0
Passed	4621
Skipped	915
Total	5536

💚 Flaky test report

Tests succeeded.

🤖 GitHub comments

Expand to view the GitHub comments

To re-run your PR in the CI, just comment with:

• /test : Re-trigger the build.

• /package : Generate the packages and run the E2E tests.

• /beats-tester : Run the installation tests with beats-tester.

• run elasticsearch-ci/docs : Re-trigger the docs validation. (use unformatted text in the comment!)

[miltonhultgren]

These changes look good but we'll need to update the mappings for the xpack mode which live here in the Elasticsearch repo as well as the mappings for the Integration which live here.

[philippkahr]

@miltonhultgren :

ES: elastic/elasticsearch#107471
Integration: elastic/integrations#9594

[miltonhultgren]

I should have reviewed this more carefully yesterday!

We first need to wrap the access in a c.Dict to go into indices.shard_stats in the response, where we'll then find the field total_count. We also make that Dict optional so in case it's not there (as in older versions) we just skip grabbing that stat.

This should make the tests pass.