Add Logstash release notes (#2964)

docs/en/install-upgrade/index.asciidoc

@@ -14,6 +14,20 @@ include::installing-stack-demo-secure.asciidoc[]
 
 include::air-gapped-install.asciidoc[]
 
+include::serverless-changelog.asciidoc[]
+
+include::breaking.asciidoc[]
+
+include::release-notes/release-notes.asciidoc[leveloffset=+1]
+
+include::release-notes/release-notes-elasticsearch.asciidoc[leveloffset=+2]
+
+include::release-notes/release-notes-kibana.asciidoc[leveloffset=+2]
+
+include::release-notes/release-notes-logstash.asciidoc[leveloffset=+2]
+
+include::release-notes/release-notes-security.asciidoc[leveloffset=+2]
+
 include::upgrading-stack.asciidoc[]
 
 include::upgrade-orchestrator.asciidoc[]
@@ -40,18 +54,4 @@ include::upgrading-kibana.asciidoc[]
 
 // include::upgrading-agent.asciidoc[]
 
-include::serverless-changelog.asciidoc[]
-
-include::breaking.asciidoc[]
-
-include::release-notes/release-notes.asciidoc[leveloffset=+1]
-
-include::release-notes/release-notes-elasticsearch.asciidoc[leveloffset=+2]
-
-include::release-notes/release-notes-kibana.asciidoc[leveloffset=+2]
-
-include::release-notes/release-notes-logstash.asciidoc[leveloffset=+2]
-
-include::release-notes/release-notes-security.asciidoc[leveloffset=+2]
-
 include::redirects.asciidoc[]

docs/en/install-upgrade/release-notes/release-notes-logstash.asciidoc

@@ -4,5 +4,112 @@
 <titleabbrev>{ls}</titleabbrev>
 ++++
 
-coming::[9.0.0-beta1]
+== Breaking changes
 
+[[pipeline-buffer-type]]
+=== Pipeline buffer type changed to 'heap'
+
+Set `pipeline.buffer.type` to `direct` to continue using direct memory with {agent}, {beats}, TCP, and HTTP input plugins https://github.com/elastic/logstash/pull/16500[#16500]
+
+[[removed-params]]
+=== Removed deprecated params
+
+`http.*` params replaced by `api.*` are removed https://github.com/elastic/logstash/pull/16552[#16552]
+
+`event_api.tags.illegal` no longer exists. 
+Instead, {ls} generates `_tagsparsefailure` in the event `tags` and the illegal value is written to the `_tags` field https://github.com/elastic/logstash/pull/16461[#16461]
+
+[[removed-modules]]
+=== Removed {ls} modules
+
+Removed netflow, fb_apache and azure https://github.com/elastic/logstash/pull/16514[#16514]
+
+Removed Arcsight module and the modules framework https://github.com/elastic/logstash/pull/16794[#16794]
+
+Removed ingest-converter https://github.com/elastic/logstash/pull/16453[#16453]
+
+
+[[jdk-11-support-drop]]
+=== JDK 11 support drop
+
+Starting with {ls} 9.0, we no longer support Java 11 https://github.com/elastic/logstash/pull/16443[#16443]
+
+[[docker-base-image-change]]
+=== Docker base image change
+
+{ls} on Docker, Ubuntu base image changed to UBI https://github.com/elastic/logstash/pull/16599[#16599]
+
+[[allow-superuser]]
+=== {ls} does not run with superuser by default
+
+Starting with 9.0, set `allow_superuser` to `true` if you prefer running {ls} as a superuser https://github.com/elastic/logstash/pull/16558[#16558]
+
+[[allow-legacy-monitoring]]
+=== {ls} introduces new setting to allow legacy internal monitoring
+
+Starting from 9.0, set `xpack.monitoring.allow_legacy_collection` to `true` to explicitly permit legacy monitoring https://github.com/elastic/logstash/pull/16586[#16586]
+
+[[avoid-collision-on-json-fileds]]
+=== {ls} avoids JSON log lines collision
+
+`log.format.json.fix_duplicate_message_fields` config is enabled by default to avoid collision on `message` field in log lines when `log.format` is JSON https://github.com/elastic/logstash/pull/16578[#16578]
+
+== Plugin releases
+
+*elastic_integration Filter - 9.0.0*
+
+* 9.0 prerelease compatible plugin version https://github.com/elastic/logstash-filter-elastic_integration/pull/265[#265]
+
+*Elasticsearch Filter - 4.1.0*
+
+* Remove deprecated SSL settings https://github.com/logstash-plugins/logstash-filter-elasticsearch/pull/183[#183]
+
+*Http Filter - 2.0.0*
+
+* Remove deprecated SSL settings https://github.com/logstash-plugins/logstash-filter-http/pull/54[#54]
+
+*Beats Input - 7.0.1*
+
+* Remove deprecated SSL settings https://github.com/logstash-plugins/logstash-input-beats/pull/508[#508]
+
+*Elastic_serverless_forwarder Input - 2.0.0*
+
+* Remove deprecated SSL settings https://github.com/logstash-plugins/logstash-input-elastic_serverless_forwarder/pull/11[#11]
+
+* Promote from technical preview to GA https://github.com/logstash-plugins/logstash-input-elastic_serverless_forwarder/pull/10[#10]
+
+*Elasticsearch Input - 5.0.0*
+
+* Remove deprecated SSL settings https://github.com/logstash-plugins/logstash-input-elasticsearch/pull/213[#213]
+
+*Http Input - 4.1.0*
+
+* Remove deprecated SSL settings https://github.com/logstash-plugins/logstash-input-http/pull/182[#182]
+
+*Http_poller Input - 6.0.0*
+
+* Remove deprecated SSL settings https://github.com/logstash-plugins/logstash-input-http_poller/pull/149[#149]
+
+*Tcp Input - 7.0.0*
+
+* Remove deprecated SSL settings https://github.com/logstash-plugins/logstash-input-tcp/pull/228[#228]
+
+*Kafka Integration - 11.6.0*
+
+* Support additional `oauth` and `sasl` configuration options for configuring kafka client https://github.com/logstash-plugins/logstash-integration-kafka/pull/189[#189]
+
+*Snmp Integration - 4.0.6*
+
+* [DOC] Fix typo in snmptrap migration section https://github.com/logstash-plugins/logstash-integration-snmp/pull/74[#74]
+
+*Elasticsearch Output - 12.0.2*
+
+* Remove deprecated SSL settings https://github.com/logstash-plugins/logstash-output-elasticsearch/pull/1197[#1197]
+
+*Http Output - 6.0.0*
+
+* Remove deprecated SSL settings https://github.com/logstash-plugins/logstash-output-http/pull/147[#147]
+
+*Tcp Output - 7.0.0*
+
+* Remove deprecated SSL settings https://github.com/logstash-plugins/logstash-output-tcp/pull/58[#58]