[DOC] Get _scripts API does not work

[prabhupant]

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If we look at the scripts API here https://opensearch.org/docs/latest/api-reference/script-apis/get-stored-script/, it says we can use GET _scripts/my-first-script to retrieve a script but this throws an error

{
  "error": {
    "root_cause": [
      {
        "type": "invalid_index_name_exception",
        "reason": "Invalid index name [_scripts], must not start with '_'.",
        "index": "_scripts",
        "index_uuid": "_na_"
      }
    ],
    "type": "invalid_index_name_exception",
    "reason": "Invalid index name [_scripts], must not start with '_'.",
    "index": "_scripts",
    "index_uuid": "_na_"
  },
  "status": 400
}

Instead, we have to use GET _cluster/state/metadata?filter_path=metadata.stored_scripts to get the script. The document should mention this

Version: List the OpenSearch version to which this issue applies, e.g. 2.14, 2.12--2.14, or all.

What other resources are available? Provide links to related issues, POCs, steps for testing, etc.

[Naarcha-AWS]

@prabhupant: I think the example assumes that a script named my-first-script exists within the cluster. I'll update the endpoint at the top to use a generic , which should be replaced with a script that exists in your cluster.

[kolchfa-aws]

@prabhupant Here's a complete example:

PUT _scripts/my-first-script
{
  "script": {
      "lang": "painless",
      "source": """
          int total = 0;
          for (int i = 0; i < doc['ratings'].length; ++i) {
            total += doc['ratings'][i];
          }
          return total;
        """
  }
}

GET _scripts/my-first-script