[DOCS] Fix failures in :docs:integTest

[setiah]

Issues

• unknown setting [script.painless.regex.enabled]
• unknown setting [reindex.remote.whitelist]

More details

> Task :docs:integTest FAILED

=== Standard output of node `node{:docs:integTest-0}` ===

»    ↓ errors and warnings from /home/ubuntu/search/docs/build/testclusters/integTest-0/logs/es.stdout.log ↓
» ERROR][o.e.b.ElasticsearchUncaughtExceptionHandler] [node-0] uncaught exception in thread [main]
»  org.elasticsearch.bootstrap.StartupException: java.lang.IllegalArgumentException: unknown setting [script.painless.regex.enabled] please check that any required plugins are installed, or check the breaking changes documentation for removed settings
»       at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:173) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»       at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:160) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»       at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:86) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»       at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:127) ~[elasticsearch-cli-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»       at org.elasticsearch.cli.Command.main(Command.java:90) ~[elasticsearch-cli-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»       at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:126) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»       at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:92) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»  Caused by: java.lang.IllegalArgumentException: unknown setting [script.painless.regex.enabled] please check that any required plugins are installed, or check the breaking changes documentation for removed settings
»       at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:544) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»       at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:489) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»       at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:460) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»       at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:431) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»       at org.elasticsearch.common.settings.SettingsModule.<init>(SettingsModule.java:149) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»       at org.elasticsearch.node.Node.<init>(Node.java:405) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»       at org.elasticsearch.node.Node.<init>(Node.java:289) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»       at org.elasticsearch.bootstrap.Bootstrap$5.<init>(Bootstrap.java:227) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»       at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:227) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»       at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:393) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»       at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:169) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»       ... 6 more
»       Suppressed: java.lang.IllegalArgumentException: unknown setting [reindex.remote.whitelist] please check that any required plugins are installed, or check the breaking changes documentation for removed settings
»               at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:544) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»               at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:489) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»               at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:460) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»               at org.elasticsearch.common.settings.AbstractScopedSettings.validate(AbstractScopedSettings.java:431) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»               at org.elasticsearch.common.settings.SettingsModule.<init>(SettingsModule.java:149) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»               at org.elasticsearch.node.Node.<init>(Node.java:405) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»               at org.elasticsearch.node.Node.<init>(Node.java:289) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»               at org.elasticsearch.bootstrap.Bootstrap$5.<init>(Bootstrap.java:227) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»               at org.elasticsearch.bootstrap.Bootstrap.setup(Bootstrap.java:227) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»               at org.elasticsearch.bootstrap.Bootstrap.init(Bootstrap.java:393) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»               at org.elasticsearch.bootstrap.Elasticsearch.init(Elasticsearch.java:169) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»               at org.elasticsearch.bootstrap.Elasticsearch.execute(Elasticsearch.java:160) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»               at org.elasticsearch.cli.EnvironmentAwareCommand.execute(EnvironmentAwareCommand.java:86) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»               at org.elasticsearch.cli.Command.mainWithoutErrorHandling(Command.java:127) ~[elasticsearch-cli-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»               at org.elasticsearch.cli.Command.main(Command.java:90) ~[elasticsearch-cli-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»               at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:126) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»               at org.elasticsearch.bootstrap.Elasticsearch.main(Elasticsearch.java:92) ~[elasticsearch-7.10.3-SNAPSHOT.jar:7.10.3-SNAPSHOT]
»   ↓ last 40 non error or warning messages from /home/ubuntu/search/docs/build/testclusters/integTest-0/logs/es.stdout.log ↓

[setiah]

The ES process bootstrap failure happens due to above error where it is failing to recognize some settings. The issue is as part of merge from main, which has default artifact removal changes, the integTest distribution setting was removed, which made it to start with default INTEG-TEST distribution, which only supports transport-netty4 module. Setting it to the oss distribution, made it load all official modules, and the bootstrap passed.