Repeated deprecation setting error on main after #15679

[andsel]

Description of the problem including expected versus actual behavior:
After merge of PR #15679 which introduced new Java classes for base, aliased and Boolean setting translating from Ruby existing code, if Logstash runs with the reload of a pipeline flag (both as command line --config.reload.automatic or configuring it in config/logstash.yml, it starts repeating the following error log:

[2024-10-03T14:03:12,018][WARN ][org.logstash.settings.DeprecatedAlias] The value of setting `api.enabled` has been queried by its deprecated alias `http.enabled`. Code should be updated to query `api.enabled` instead

This happens only when the pipeline is configured in config/pipelines.yml, both as config.string or with path path.config.
Instead, it doesn't happen when running directly the pipeline form the file with logstash -f simple_pipeline.conf

Steps to reproduce:

Please include a minimal but complete recreation of the problem,
including (e.g.) pipeline definition(s), settings, locale, etc. The easier
you make for us to reproduce it, the more likely that somebody will take the
time to look at it.

1. edit config/pipelines.yml adding

- pipeline.id: test
  config.string: "input{ tcp { port => 12345 } } output { stdout{} }"

2. Run Logstash with

bin/logstash --config.reload.automatic

If the reload it's not enabled, it doesn't happen.
Also note that it happend every 3 seconds (the default value of config.reload.interval) and appears always twice

Provide logs (if relevant):

[2024-10-03T14:12:36,209][INFO ][logstash.agent           ] Pipelines running {:count=>1, :running_pipelines=>[:test], :non_running_pipelines=>[]}


[2024-10-03T14:12:39,242][WARN ][org.logstash.settings.DeprecatedAlias] The value of setting `api.enabled` has been queried by its deprecated alias `http.enabled`. Code should be updated to query `api.enabled` instead
[2024-10-03T14:12:39,245][WARN ][org.logstash.settings.DeprecatedAlias] The value of setting `api.enabled` has been queried by its deprecated alias `http.enabled`. Code should be updated to query `api.enabled` instead


[2024-10-03T14:12:42,234][WARN ][org.logstash.settings.DeprecatedAlias] The value of setting `api.enabled` has been queried by its deprecated alias `http.enabled`. Code should be updated to query `api.enabled` instead
[2024-10-03T14:12:42,235][WARN ][org.logstash.settings.DeprecatedAlias] The value of setting `api.enabled` has been queried by its deprecated alias `http.enabled`. Code should be updated to query `api.enabled` instead


[2024-10-03T14:12:45,230][WARN ][org.logstash.settings.DeprecatedAlias] The value of setting `api.enabled` has been queried by its deprecated alias `http.enabled`. Code should be updated to query `api.enabled` instead
[2024-10-03T14:12:45,233][WARN ][org.logstash.settings.DeprecatedAlias] The value of setting `api.enabled` has been queried by its deprecated alias `http.enabled`. Code should be updated to query `api.enabled` instead

[andsel]

This problem raises from the fact the Agent cyclically (if autoreload is enabled) reload and resolve pipeline configuration, in checking if Settings instances has changed, it invokes the equals method which goes deep to the DeprecatedAlias.value and so the log.

In more details:

logstash/logstash-core/lib/logstash/agent.rb

Line 132 in e84fb45

converge_state_and_update unless stopped?

logstash/logstash-core/lib/logstash/agent.rb

Line 192 in e84fb45

converge_result = resolve_actions_and_converge_state(results.response)

logstash/logstash-core/lib/logstash/agent.rb

Line 339 in e84fb45

pipeline_actions = resolve_actions(pipeline_configs)

logstash/logstash-core/lib/logstash/agent.rb

Line 421 in e84fb45

@state_resolver.resolve(@pipelines_registry, pipeline_configs)

logstash/logstash-core/lib/logstash/state_resolver.rb

Line 38 in e84fb45

if pipeline_config != pipeline.pipeline_config

logstash/logstash-core/src/main/java/org/logstash/config/ir/PipelineConfig.java

Line 158 in e84fb45

this.settings.equals(cother.settings);

logstash/logstash-core/lib/logstash/settings.rb

Lines 226 to 229 in e84fb45

	def ==(other)
	return false unless other.kind_of?(::LogStash::Settings)
	self.to_hash == other.to_hash
	end

In checking equality of hash map both keys and values of hash maps are accessed. The map (due to the with_deprecated_alias) contains 2 settings one for api.enabled which is the SettingWithDeprecatedAlias proxy and another for http.enabled which is the instance of DeprecatedAlias. So it seems that every time this comparison process accesses an instance of DeprecatedAlias then the value() method is also invoked.

[andsel]

The motivation of access the value is that Settings#to_hash method does it:

logstash/logstash-core/lib/logstash/settings.rb

Lines 154 to 161 in e84fb45

	def to_hash
	hash = {}
	@settings.each do |name, setting|
	next if setting.kind_of? Setting::DeprecatedAlias
	hash[name] = setting.value
	end
	hash
	end