add a discard output

CHANGELOG.next.asciidoc

@@ -204,6 +204,7 @@ https://github.com/elastic/beats/compare/v8.8.1\...main[Check the HEAD diff]
 - Add support for Active Directory an entity analytics provider. {pull}37919[37919]
 - Add debugging breadcrumb to logs when writing request trace log. {pull}38636[38636]
 - added benchmark input {pull}37437[37437]
+- added benchmark input and discard output {pull}37437[37437]
 
 *Auditbeat*
 

libbeat/docs/outputs-list.asciidoc

@@ -24,6 +24,9 @@ endif::[]
 ifndef::no_console_output[]
 * <<console-output>>
 endif::[]
+ifndef::no_discard_output[]
+* <<discard-output>>
+endif::[]
 
 //# end::outputs-list[]
 
@@ -77,6 +80,13 @@ endif::[]
 include::{libbeat-outputs-dir}/console/docs/console.asciidoc[]
 endif::[]
 
+ifndef::no_discard_output[]
+ifdef::requires_xpack[]
+[role="xpack"]
+endif::[]
+include::{libbeat-outputs-dir}/discard/docs/discard.asciidoc[]
+endif::[]
+
 ifndef::no_codec[]
 ifdef::requires_xpack[]
 [role="xpack"]

libbeat/outputs/discard/config.go

@@ -0,0 +1,30 @@
+// Licensed to Elasticsearch B.V. under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. Elasticsearch B.V. licenses this file to you under
+// the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+package discard
+
+import (
+	"github.com/elastic/elastic-agent-libs/config"
+)
+
+type discardOutConfig struct {
+	Queue config.Namespace `config:"queue"`
+}
+
+func defaultConfig() discardOutConfig {
+	return discardOutConfig{}
+}

libbeat/outputs/discard/discard.go

@@ -0,0 +1,82 @@
+// Licensed to Elasticsearch B.V. under one or more contributor
+// license agreements. See the NOTICE file distributed with
+// this work for additional information regarding copyright
+// ownership. Elasticsearch B.V. licenses this file to you under
+// the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+package discard
+
+import (
+	"context"
+
+	"github.com/elastic/beats/v7/libbeat/beat"
+	"github.com/elastic/beats/v7/libbeat/outputs"
+	"github.com/elastic/beats/v7/libbeat/publisher"
+	"github.com/elastic/elastic-agent-libs/config"
+	"github.com/elastic/elastic-agent-libs/logp"
+)
+
+func init() {
+	outputs.RegisterType("discard", makeDiscard)
+}
+
+type discardOutput struct {
+	log      *logp.Logger
+	beat     beat.Info
+	observer outputs.Observer
+}
+
+func makeDiscard(
+	_ outputs.IndexManager,
+	beat beat.Info,
+	observer outputs.Observer,
+	cfg *config.C,
+) (outputs.Group, error) {
+	out := &discardOutput{
+		log:      logp.NewLogger("discard"),
+		beat:     beat,
+		observer: observer,
+	}
+	doConfig := defaultConfig()
+	if err := cfg.Unpack(&doConfig); err != nil {
+		return outputs.Fail(err)
+	}
+
+	// disable bulk support in publisher pipeline
+	_ = cfg.SetInt("bulk_max_size", -1, -1)
+	out.log.Infof("Initialized discard output")
+	return outputs.Success(doConfig.Queue, -1, 0, out)
+}
+
+// Implement Outputer
+func (out *discardOutput) Close() error {
+	return nil
+}
+
+func (out *discardOutput) Publish(_ context.Context, batch publisher.Batch) error {
+	defer batch.ACK()
+
+	st := out.observer
+	events := batch.Events()
+	st.NewBatch(len(events))
+	for range events {
+		st.WriteError(nil)
+	}
+	st.Acked(len(events))
+	return nil
+}
+
+func (out *discardOutput) String() string {
+	return "discard"
+}

libbeat/outputs/discard/docs/discard.asciidoc

@@ -0,0 +1,34 @@
+[[discard-output]]
+=== Configure the Discard output
+
+++++
+<titleabbrev>Discard</titleabbrev>
+++++
+
+The Discard output throws away data.
+
+WARNING: The Discard output should be used only for development or
+debugging issues.  Data is lost.
+
+This can be useful if you want to work on your input configuration
+without needing to configure an output.  It can also be useful to test
+how changes in input and processor configuration affect performance.
+
+Example configuration:
+
+["source","yaml",subs="attributes"]
+------------------------------------------------------------------------------
+output.discard:
+  enabled: true
+------------------------------------------------------------------------------
+
+==== Configuration options
+
+You can specify the following `output.discard` options in the +{beatname_lc}.yml+ config file:
+
+===== `enabled`
+
+The enabled config is a boolean setting to enable or disable the output. If set
+to false, the output is disabled.
+
+The default value is `true`.

libbeat/publisher/includes/includes.go

@@ -22,6 +22,7 @@ import (
 	_ "github.com/elastic/beats/v7/libbeat/outputs/codec/format"
 	_ "github.com/elastic/beats/v7/libbeat/outputs/codec/json"
 	_ "github.com/elastic/beats/v7/libbeat/outputs/console"
+	_ "github.com/elastic/beats/v7/libbeat/outputs/discard"
 	_ "github.com/elastic/beats/v7/libbeat/outputs/elasticsearch"
 	_ "github.com/elastic/beats/v7/libbeat/outputs/fileout"
 	_ "github.com/elastic/beats/v7/libbeat/outputs/kafka"

x-pack/filebeat/docs/inputs/input-benchmark.asciidoc

@@ -6,12 +6,12 @@
 === Benchmark input
 
 ++++
-<titleabbrev>generic event generator</titleabbrev>
+<titleabbrev>Benchmark</titleabbrev>
 ++++
 
 beta[]
 
-The benchmark input generates generic events and sends them to the output.  This can be useful when you want to benchmark the difference between outputs or output settings.
+The Benchmark input generates generic events and sends them to the output.  This can be useful when you want to benchmark the difference between outputs or output settings.
 
 Example configurations:
 
@@ -49,7 +49,7 @@ Send 5 events per second example:
 
 ==== Configuration options
 
-The `benchmark` input supports the following configuration options plus the
+The Benchmark input supports the following configuration options plus the
 <<{beatname_lc}-input-{type}-common-options>> described later.
 
 [float]