Improve handling of max_inbound_message_body_size (avoid hard-coded default; apply only when configured)

docs/input-rabbitmq.asciidoc

@@ -97,6 +97,7 @@ This plugin supports the following configuration options plus the <<plugins-{typ
 | <<plugins-{type}s-{plugin}-key>> |<<string,string>>|No
 | <<plugins-{type}s-{plugin}-metadata_enabled>> |<<boolean,boolean>>|No
 | <<plugins-{type}s-{plugin}-passive>> |<<boolean,boolean>>|No
+| <<plugins-{type}s-{plugin}-max_inbound_message_body_size>> | <<number,number>> | No
 | <<plugins-{type}s-{plugin}-password>> |<<password,password>>|No
 | <<plugins-{type}s-{plugin}-port>> |<<number,number>>|No
 | <<plugins-{type}s-{plugin}-prefetch_count>> |<<number,number>>|No
@@ -259,6 +260,16 @@ This is only relevant for direct or topic exchanges.
 * Routing keys are ignored on fanout exchanges.
 * Wildcards are not valid on direct exchanges.
 
+[id="plugins-{type}s-{plugin}-max_inbound_message_body_size"]
+===== `max_inbound_message_body_size`
+
+* Value type: <<number,number>>
+* Required: No
+* Default: Java client default
+
+Sets the maximum inbound message body size (in bytes) accepted by the RabbitMQ Java client.
+If not configured, the Java client's built-in default is used.
+
 [id="plugins-{type}s-{plugin}-metadata_enabled"]
 ===== `metadata_enabled`
 

lib/logstash/plugin_mixins/rabbitmq_connection.rb

@@ -75,6 +75,9 @@ def setup_rabbitmq_connection_config
         # Passive queue creation? Useful for checking queue existance without modifying server state
         config :passive, :validate => :boolean, :default => false
 
+        # Max inbound message size (in bytes). Optional.
+        config :max_inbound_message_body_size, :validate => :number
+
         # Extra queue arguments as an array.
         # To make a RabbitMQ queue mirrored, use: `{"x-ha-policy" => "all"}`
         config :arguments, :validate => :array, :default => {}
@@ -104,6 +107,7 @@ def rabbitmq_settings
 
         s[:connection_timeout] = @connection_timeout || 0
         s[:requested_heartbeat] = @heartbeat || 0
+        s[:max_inbound_message_body_size] = @max_inbound_message_body_size if @max_inbound_message_body_size
 
         if @ssl
           s[:tls] = @ssl_version

spec/plugin_mixins/rabbitmq_connection_spec.rb

@@ -75,6 +75,16 @@ def register
       expect(instance.rabbitmq_settings[:tls_certificate_password]).to eql(rabbitmq_settings["ssl_certificate_password"])
     end
 
+    it "sets max_inbound_message_body_size when configured" do
+      instance_with_size = klass.new(rabbitmq_settings.merge("max_inbound_message_body_size" => 104857600))
+      expect(instance_with_size.rabbitmq_settings[:max_inbound_message_body_size]).to eql(104857600)
+    end
+
+    it "does not set max_inbound_message_body_size when not configured" do
+      expect(instance.rabbitmq_settings.key?(:max_inbound_message_body_size)).to be(false)
+    end
+
+
     it_behaves_like 'it sets the addresses correctly'
 
     context 'with a custom port' do