Docs for output-elastic_app_search not getting updated properly

[karenzone]

We recently added a new integration for enterprise_search[1] and followed up with changes[2] to the metadata.json file to get docs generating properly. The PR added the integration to the json file, and removed the stand-alone output-elastic_app_search.

In addition to the default_plugin settings misbehaving (as described in #56), updates for output-elastic_app_search doc--published version and date, doc content, etc.--are not getting picked up.[3] I removed the regressions and corrected other info manually.[4]

Of interest:

• This issue and Unexpected value for default_plugin setting #56 are happening only on master, and so lockfile issues aren't a factor. Both default_plugin setting and doc updates are working as expected on 7.x.[5]
• The integration and the elastic_workplace_search output are updating correctly. This plugin was stand-alone before it was pulled into the integration, but that hasn't been an issue with other stand-alone to integration moves.

[1] logstash-plugins/logstash-integration-elastic_enterprise_search#1
[2] elastic/logstash#12925
[3] https://github.com/elastic/logstash-docs/pull/1055/files#diff-f6c88e0d8424c8335471345a879fd618835ae1965988329e492eec97fb5f0274
[4] elastic/logstash-docs#1057
[5] https://github.com/elastic/logstash-docs/pull/1056/files#diff-f6c88e0d8424c8335471345a879fd618835ae1965988329e492eec97fb5f0274

Related: #56

[karenzone]

Another interesting finding... Updates working as expected for the Versioned Plugin Reference (on versioned_plugin_docs branch):

• https://www.elastic.co/guide/en/logstash-versioned-plugins/current/output-elastic_app_search-index.html
• https://www.elastic.co/guide/en/logstash-versioned-plugins/current/output-elastic_workplace_search-index.html

Confirming that this issue manifests on master branch only.