訳あって調べてみました。
調査バージョン
IBM Cloud Private 2.1.0.3
イメージ名
ibmcom/logstash:5.5.1
インストール済プラグイン一覧
logstash-codec-cef
logstash-codec-collectd
logstash-codec-dots
logstash-codec-edn
logstash-codec-edn_lines
logstash-codec-es_bulk
logstash-codec-fluent
logstash-codec-graphite
logstash-codec-json
logstash-codec-json_lines
logstash-codec-line
logstash-codec-msgpack
logstash-codec-multiline
logstash-codec-netflow
logstash-codec-plain
logstash-codec-rubydebug
logstash-filter-clone
logstash-filter-csv
logstash-filter-date
logstash-filter-dissect
logstash-filter-dns
logstash-filter-drop
logstash-filter-fingerprint
logstash-filter-geoip
logstash-filter-grok
logstash-filter-json
logstash-filter-kv
logstash-filter-metrics
logstash-filter-mutate
logstash-filter-ruby
logstash-filter-sleep
logstash-filter-split
logstash-filter-syslog_pri
logstash-filter-throttle
logstash-filter-urldecode
logstash-filter-useragent
logstash-filter-uuid
logstash-filter-xml
logstash-input-beats
logstash-input-couchdb_changes
logstash-input-dead_letter_queue
logstash-input-elasticsearch
logstash-input-exec
logstash-input-file
logstash-input-ganglia
logstash-input-gelf
logstash-input-generator
logstash-input-graphite
logstash-input-heartbeat
logstash-input-http
logstash-input-http_poller
logstash-input-imap
logstash-input-irc
logstash-input-jdbc
logstash-input-kafka
logstash-input-log4j
logstash-input-lumberjack
logstash-input-pipe
logstash-input-rabbitmq
logstash-input-redis
logstash-input-s3
logstash-input-snmptrap
logstash-input-sqs
logstash-input-stdin
logstash-input-syslog
logstash-input-tcp
logstash-input-twitter
logstash-input-udp
logstash-input-unix
logstash-input-xmpp
logstash-output-cloudwatch
logstash-output-csv
logstash-output-elasticsearch
logstash-output-file
logstash-output-graphite
logstash-output-http
logstash-output-irc
logstash-output-kafka
logstash-output-nagios
logstash-output-null
logstash-output-pagerduty
logstash-output-pipe
logstash-output-rabbitmq
logstash-output-redis
logstash-output-s3
logstash-output-sns
logstash-output-sqs
logstash-output-statsd
logstash-output-stdout
logstash-output-tcp
logstash-output-udp
logstash-output-webhdfs
logstash-output-xmpp
logstash-patterns-core
x-pack