Deprecation Logger Support Mixin

This gem provides an API-compatible implementation of the Logstash Deprecation Logger introduced in Logstash v7.6. It can be added as a dependency of any plugin that wishes to use the deprecation logger while still supporting older Logstash versions.

1. Add this gem as a runtime dependency of your plugin:

   Gem::Specification.new do |s|
     # ...
   
     s.add_runtime_dependency 'logstash-mixin-deprecation_logger_support', '~>1.0'
   end

2. In your plugin code, require this library and include it into your class or module that already inherits LogStash::Util::Loggable:

   require 'logstash/plugin_mixins/deprecation_logger_support'
   
   class LogStash::Inputs::Foo < Logstash::Inputs::Base
     include LogStash::PluginMixins::DeprecationLoggerSupport
   
     # ...
   end

3. Use the deprecation logger; your plugin does not need to know whether the deprecation logger was provided by Logstash core or by this gem.

     def register
       deprecation_logger.deprecated("your message")
     end

This gem:

• MUST remain API-stable at 1.x
• MUST NOT introduce additional runtime dependencies