Response errors with codes other than "400"

Problem/Motivation

When I first setup Elasticsearch using this module, I ran into an error while indexing. When I checked the log, all I saw was this:

Drupal\search_api\SearchApiException while trying to index items on index Paragraphs Index: An error occurred during indexing. Check your watchdog for more information. in Drupal\elasticsearch_connector\Plugin\search_api\backend\SearchApiElasticsearchBackend->indexItems() (line 508 of /app/web/modules/contrib/elasticsearch_connector/src/Plugin/search_api/backend/SearchApiElasticsearchBackend.php)

I didn't see any other, more specific information about the error in the log, which this error seems to elude to. Enabling the debugger, and dropping a breakpoint in the spot of the thrown exception allowed me to see what was happening. The error I was receiving:

status: 403
type: cluster_block_exception
reasion: blocked by: [FORBIDDEN/12/index read-only / allow delete (api)];

However, the error itself is not logged unless the code == '400':

$item['index']['status'] == '400'

So these 403 errors don't get logged, because '400' != 403. Obviously there is some misconfiguration in my local Elasticsearch server. But the motivation for this issue is to provide more helpful debugging information up front.

I will also point out that this status code value appears to be an integer, and not a string as it's compared to.

Proposed resolution

I suggest we cast the status code to a string, and compare whether the status code is within the 400 (or 500?) range.