Add configuration parameters for rdkafka config

lib/fluent/plugin/in_rdkafka_group.rb

@@ -9,6 +9,16 @@ class Fluent::Plugin::RdKafkaGroupInput < Fluent::Plugin::Input
 
   helpers :thread, :parser, :compat_parameters
 
+  config_param :brokers, :string, :default => 'localhost:9092',
+                 :desc => <<-DESC
+Set brokers directly:
+<broker1_host>:<broker1_port>,<broker2_host>:<broker2_port>,..
+Brokers: you can choose to use either brokers or zookeeper.
+DESC
+
+  config_param :group_id, :string, :default => 'fluentd',
+                :desc => "A group id for the consumer."
+
   config_param :topics, :string,
                :desc => "Listening topics(separate with comma',')."
 
@@ -47,8 +57,27 @@ class Fluent::Plugin::RdKafkaGroupInput < Fluent::Plugin::Input
   config_param :max_batch_size, :integer, :default => 10000,
                :desc => "Maximum number of log lines emitted in a single batch."
 
-  config_param :kafka_configs, :hash, :default => {},
-               :desc => "Kafka configuration properties as desribed in https://github.com/edenhill/librdkafka/blob/master/CONFIGURATION.md"
+  config_param :idempotent, :bool, :default => false, :desc => 'Enable idempotent producer'
+
+  config_param :max_send_retries, :integer, :default => 2,
+               :desc => "Number of times to retry sending of messages to a leader. Used for message.send.max.retries"
+  config_param :required_acks, :integer, :default => -1,
+               :desc => "The number of acks required per request. Used for request.required.acks"
+  config_param :ack_timeout, :time, :default => nil,
+               :desc => "How long the producer waits for acks. Used for request.timeout.ms"
+  config_param :compression_codec, :string, :default => nil,
+               :desc => <<-DESC
+The codec the producer uses to compress messages. Used for compression.codec
+Supported codecs: (gzip|snappy)
+DESC
+
+  config_param :rdkafka_buffering_max_ms, :integer, :default => nil, :desc => 'Used for queue.buffering.max.ms'
+  config_param :rdkafka_buffering_max_messages, :integer, :default => nil, :desc => 'Used for queue.buffering.max.messages'
+  config_param :rdkafka_message_max_bytes, :integer, :default => nil, :desc => 'Used for message.max.bytes'
+  config_param :rdkafka_message_max_num, :integer, :default => nil, :desc => 'Used for batch.num.messages'
+
+  config_param :rdkafka_options, :hash, :default => {},
+               :desc => "Set any rdkafka configuration. See https://github.com/edenhill/librdkafka/blob/master/CONFIGURATION.md"
 
   config_section :parse do
     config_set_default :@type, 'json'
@@ -91,7 +120,7 @@ def configure(conf)
     log.warn "The in_rdkafka_group consumer was not yet tested under heavy production load. Use it at your own risk!"
 
     log.info "Will watch for topics #{@topics} at brokers " \
-              "#{@kafka_configs["bootstrap.servers"]} and '#{@kafka_configs["group.id"]}' group"
+              "#{@brokers} and '#{@group_id}' group"
 
     @topics = _config_to_array(@topics)
 
@@ -141,6 +170,55 @@ def setup_parser(parser_conf)
     end
   end
 
+  def build_config
+    config = {:"bootstrap.servers" => @brokers}
+
+    if @ssl_ca_cert && @ssl_ca_cert[0]
+      ssl = true
+      config[:"ssl.ca.location"] = @ssl_ca_cert[0]
+      config[:"ssl.certificate.location"] = @ssl_client_cert if @ssl_client_cert
+      config[:"ssl.key.location"] = @ssl_client_cert_key if @ssl_client_cert_key
+      config[:"ssl.key.password"] = @ssl_client_cert_key_password if @ssl_client_cert_key_password
+    end
+
+    if @principal
+      sasl = true
+      config[:"sasl.mechanisms"] = "GSSAPI"
+      config[:"sasl.kerberos.principal"] = @principal
+      config[:"sasl.kerberos.service.name"] = @service_name if @service_name
+      config[:"sasl.kerberos.keytab"] = @keytab if @keytab
+    end
+
+    if ssl && sasl
+      security_protocol = "SASL_SSL"
+    elsif ssl && !sasl
+      security_protocol = "SSL"
+    elsif !ssl && sasl
+      security_protocol = "SASL_PLAINTEXT"
+    else
+      security_protocol = "PLAINTEXT"
+    end
+    config[:"security.protocol"] = security_protocol
+
+    config[:"compression.codec"] = @compression_codec if @compression_codec
+    config[:"message.send.max.retries"] = @max_send_retries if @max_send_retries
+    config[:"request.required.acks"] = @required_acks if @required_acks
+    config[:"request.timeout.ms"] = @ack_timeout * 1000 if @ack_timeout
+    config[:"queue.buffering.max.ms"] = @rdkafka_buffering_max_ms if @rdkafka_buffering_max_ms
+    config[:"queue.buffering.max.messages"] = @rdkafka_buffering_max_messages if @rdkafka_buffering_max_messages
+    config[:"message.max.bytes"] = @rdkafka_message_max_bytes if @rdkafka_message_max_bytes
+    config[:"batch.num.messages"] = @rdkafka_message_max_num if @rdkafka_message_max_num
+    config[:"sasl.username"] = @username if @username
+    config[:"sasl.password"] = @password if @password
+    config[:"enable.idempotence"] = @idempotent if @idempotent
+
+    @rdkafka_options.each { |k, v|
+      config[k.to_sym] = v
+    }
+
+    config
+  end
+
   def start
     super
 
@@ -161,7 +239,8 @@ def shutdown
   end
 
   def setup_consumer
-    consumer = Rdkafka::Config.new(@kafka_configs).consumer
+    @config = build_config
+    consumer = Rdkafka::Config.new(@config).consumer
     consumer.subscribe(*@topics)
     consumer
   end