Code review changes: define specific elasticsearch gem version range, add comments on the logics to support both elastic and elasticsearch transport gems.

Author: mashhurs

CHANGELOG.md

@@ -1,5 +1,5 @@
 ## 4.1.1
-  - Adds elastic-transport client support [#191](https://github.com/logstash-plugins/logstash-filter-elasticsearch/pull/191)
+  - Add elastic-transport client support used in elasticsearch-ruby 8.x [#191](https://github.com/logstash-plugins/logstash-filter-elasticsearch/pull/191)
 
 ## 4.1.0
  - Added support for custom headers [#188](https://github.com/logstash-plugins/logstash-filter-elasticsearch/pull/188)

lib/logstash/filters/elasticsearch/client.rb

@@ -100,6 +100,10 @@ def setup_api_key(api_key)
       end
 
       def get_transport_client_class
+        # LS-core includes `elasticsearch` gem. The gem is composed of two separate gems: `elasticsearch-api` and `elasticsearch-transport`
+        # And now `elasticsearch-transport` is old, instead we have `elastic-transport`.
+        # LS-core updated `elasticsearch` > 8: https://github.com/elastic/logstash/pull/17161
+        # Following source bits are for the compatibility to support both `elasticsearch-transport` and `elastic-transport` gems
         require "elasticsearch/transport/transport/http/manticore"
         es_transport_client_type = "elasticsearch_transport"
         ::Elasticsearch::Transport::Transport::HTTP::Manticore

logstash-filter-elasticsearch.gemspec

@@ -21,7 +21,7 @@ Gem::Specification.new do |s|
 
   # Gem dependencies
   s.add_runtime_dependency "logstash-core-plugin-api", ">= 1.60", "<= 2.99"
-  s.add_runtime_dependency 'elasticsearch', ">= 7.14.9" # LS >= 6.7 and < 7.14 all used version 5.0.5
+  s.add_runtime_dependency 'elasticsearch', ">= 7.14.9", '< 9'
   s.add_runtime_dependency 'manticore', ">= 0.7.1"
   s.add_runtime_dependency 'logstash-mixin-ca_trusted_fingerprint_support', '~> 1.0'
   s.add_development_dependency 'cabin', ['~> 0.6']