Add detection of source.mode synthetics for 8.17.2 onwards

[mrodm]

Relates #2397

This PR adds support to detect synthetic mode from 8.17.2 onwards.

It looks like that starting in this version this mode is declared under the settings object:

{
  "template": {
    "settings": {
      "index": {
        "mapping": {
          "total_fields": {
            "limit": "1000",
            "ignore_dynamic_beyond_limit": "true"
          },
          "source": {
            "mode": "synthetic"
          }
        },
      }
    }
  }
}

Before this (in 8.17.1), there is also a warning message in the API response:

#! Configuring source mode in mappings is deprecated and will be removed in future versions. Use [index.mapping.source.mode] index setting instead.
{
  "template": {
    "mappings": {
      "_source": {
        "mode": "synthetic"
      }
    }
  }
}

How to test this PR locally

elastic-package stack up -v -d --version 8.17.2

cd test/packages/other/synthetic_mode

elastic-package test system -v

# Using DevTools query to check the API response to read the source mode
# POST /_index_template/_simulate_index/metrics-synthetic_mode.synthetic-25370-simulated

elastic-package stack down -v

[elasticmachine]

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Failed CI Steps

• :windows: Run unit tests

History

cc @mrodm