Backport(v1.16) Add OpenSearch sniffer class name and use it by default (#1544) (#1561)

Signed-off-by: Sergio López <[email protected]>
Signed-off-by: Kentaro Hayashi <[email protected]>
Co-authored-by: Sergio López <[email protected]>

Author: kenhys

templates/conf/fluent.conf.erb

@@ -82,6 +82,7 @@
   logstash_format "#{ENV['FLUENT_OPENSEARCH_LOGSTASH_FORMAT'] || 'false'}"
   logstash_prefix "#{ENV['FLUENT_OPENSEARCH_LOGSTASH_PREFIX'] || 'logstash'}"
   logstash_prefix_separator "#{ENV['FLUENT_OPENSEARCH_LOGSTASH_PREFIX_SEPARATOR'] || '-'}"
+  sniffer_class_name "#{ENV['FLUENT_OPENSEARCH_SNIFFER_CLASS_NAME'] || 'Fluent::Plugin::OpenSearchSimpleSniffer'}"
   <buffer>
     flush_thread_count "#{ENV['FLUENT_OPENSEARCH_BUFFER_FLUSH_THREAD_COUNT'] || '1'}"
     flush_mode "#{ENV['FLUENT_OPENSEARCH_BUFFER_FLUSH_MODE'] || 'interval'}"

templates/entrypoint.sh.erb

@@ -14,6 +14,17 @@ if [ -n "$SIMPLE_SNIFFER" -a -f "$SIMPLE_SNIFFER" ] ; then
     FLUENTD_OPT="$FLUENTD_OPT -r $SIMPLE_SNIFFER"
 fi
 
+<% end %>
+<% if target == "opensearch" %>
+
+set -e
+
+SIMPLE_SNIFFER=$( gem contents fluent-plugin-opensearch | grep opensearch_simple_sniffer.rb )
+
+if [ -n "$SIMPLE_SNIFFER" -a -f "$SIMPLE_SNIFFER" ] ; then
+    FLUENTD_OPT="$FLUENTD_OPT -r $SIMPLE_SNIFFER"
+fi
+
 <% end %>
 
 exec fluentd -c /fluentd/etc/${FLUENTD_CONF} -p /fluentd/plugins --gemfile /fluentd/Gemfile ${FLUENTD_OPT}