[receiver/splunkhecreceiver] use ACK extension in HEC receiver (#31767)

**Description:**
Adding support for ack extension in the splunkhecreceiver. The receiver
can now be configured to using different ack extensions to ack events.

**Link to tracking Issue:** #26376

---------

Co-authored-by: Antoine Toulme <antoine@toulme.name>
Co-authored-by: Curtis Robert <crobert@splunk.com>

.chloggen/hec_receiver_ack.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: 'enhancement'
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: 'splunkhecreceiver'
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "adding support for ack in the splunkhecreceiver"
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [26376]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

cmd/configschema/go.mod

@@ -483,6 +483,7 @@ require (
 	github.com/open-telemetry/opentelemetry-collector-contrib/exporter/opencensusexporter v0.98.0 // indirect
 	github.com/open-telemetry/opentelemetry-collector-contrib/exporter/opensearchexporter v0.98.0 // indirect
 	github.com/open-telemetry/opentelemetry-collector-contrib/exporter/prometheusexporter v0.98.0 // indirect
+	github.com/open-telemetry/opentelemetry-collector-contrib/extension/ackextension v0.98.0 // indirect
 	github.com/open-telemetry/opentelemetry-collector-contrib/extension/asapauthextension v0.98.0 // indirect
 	github.com/open-telemetry/opentelemetry-collector-contrib/extension/awsproxy v0.98.0 // indirect
 	github.com/open-telemetry/opentelemetry-collector-contrib/extension/basicauthextension v0.98.0 // indirect
@@ -1150,6 +1151,8 @@ replace github.com/open-telemetry/opentelemetry-collector-contrib/extension/enco
 
 replace github.com/open-telemetry/opentelemetry-collector-contrib/extension/encoding => ../../extension/encoding
 
+replace github.com/open-telemetry/opentelemetry-collector-contrib/extension/ackextension => ../../extension/ackextension
+
 replace github.com/open-telemetry/opentelemetry-collector-contrib/connector/grafanacloudconnector => ../../connector/grafanacloudconnector
 
 replace github.com/open-telemetry/opentelemetry-collector-contrib/extension/sumologicextension => ../../extension/sumologicextension

cmd/oteltestbedcol/builder-config.yaml

@@ -99,3 +99,4 @@ replaces:
   - github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatautil => ../../pkg/pdatautil
   - github.com/openshift/api v3.9.0+incompatible => github.com/openshift/api v0.0.0-20180801171038-322a19404e37
   - github.com/outcaste-io/ristretto v0.2.0 => github.com/outcaste-io/ristretto v0.2.1
+  - github.com/open-telemetry/opentelemetry-collector-contrib/extension/ackextension => ../../extension/ackextension

cmd/oteltestbedcol/go.mod

@@ -166,6 +166,7 @@ require (
 	github.com/mostynb/go-grpc-compression v1.2.2 // indirect
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f // indirect
+	github.com/open-telemetry/opentelemetry-collector-contrib/extension/ackextension v0.98.0 // indirect
 	github.com/open-telemetry/opentelemetry-collector-contrib/internal/common v0.98.0 // indirect
 	github.com/open-telemetry/opentelemetry-collector-contrib/internal/coreinternal v0.98.0 // indirect
 	github.com/open-telemetry/opentelemetry-collector-contrib/internal/filter v0.98.0 // indirect
@@ -391,3 +392,5 @@ replace github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatautil
 replace github.com/openshift/api v3.9.0+incompatible => github.com/openshift/api v0.0.0-20180801171038-322a19404e37
 
 replace github.com/outcaste-io/ristretto v0.2.0 => github.com/outcaste-io/ristretto v0.2.1
+
+replace github.com/open-telemetry/opentelemetry-collector-contrib/extension/ackextension => ../../extension/ackextension

exporter/elasticsearchexporter/integrationtest/go.mod

@@ -255,3 +255,5 @@ replace github.com/open-telemetry/opentelemetry-collector-contrib/receiver/sapmr
 replace github.com/open-telemetry/opentelemetry-collector-contrib/pkg/resourcetotelemetry => ../../../pkg/resourcetotelemetry
 
 replace github.com/open-telemetry/opentelemetry-collector-contrib/exporter/prometheusremotewriteexporter => ../../prometheusremotewriteexporter
+
+replace github.com/open-telemetry/opentelemetry-collector-contrib/extension/ackextension => ../../../extension/ackextension

go.mod

@@ -489,6 +489,7 @@ require (
 	github.com/munnerz/goautoneg v0.0.0-20191010083416-a7dc8b61c822 // indirect
 	github.com/mwitkow/go-conntrack v0.0.0-20190716064945-2f068394615f // indirect
 	github.com/nginxinc/nginx-prometheus-exporter v0.11.0 // indirect
+	github.com/open-telemetry/opentelemetry-collector-contrib/extension/ackextension v0.98.0 // indirect
 	github.com/open-telemetry/opentelemetry-collector-contrib/extension/observer v0.98.0 // indirect
 	github.com/open-telemetry/opentelemetry-collector-contrib/extension/sumologicextension v0.98.0 // indirect
 	github.com/open-telemetry/opentelemetry-collector-contrib/internal/aws/awsutil v0.98.0 // indirect
@@ -1153,3 +1154,5 @@ replace github.com/open-telemetry/opentelemetry-collector-contrib/internal/sqlqu
 replace github.com/open-telemetry/opentelemetry-collector-contrib/extension/encoding => ./extension/encoding
 
 replace github.com/open-telemetry/opentelemetry-collector-contrib/extension/encoding/otlpencodingextension => ./extension/encoding/otlpencodingextension
+
+replace github.com/open-telemetry/opentelemetry-collector-contrib/extension/ackextension => ./extension/ackextension

internal/splunk/common.go

@@ -23,11 +23,14 @@ const (
 	DefaultSeverityTextLabel   = "otel.log.severity.text"
 	DefaultSeverityNumberLabel = "otel.log.severity.number"
 	HECTokenHeader             = "Splunk"
-	HecTokenLabel              = "com.splunk.hec.access_token" // #nosec
+	HTTPSplunkChannelHeader    = "X-Splunk-Request-Channel"
+
+	HecTokenLabel = "com.splunk.hec.access_token" // #nosec
 	// HecEventMetricType is the type of HEC event. Set to metric, as per https://docs.splunk.com/Documentation/Splunk/8.0.3/Metrics/GetMetricsInOther.
 	HecEventMetricType = "metric"
 	DefaultRawPath     = "/services/collector/raw"
 	DefaultHealthPath  = "/services/collector/health"
+	DefaultAckPath     = "/services/collector/ack"
 )
 
 // AccessTokenPassthroughConfig configures passing through access tokens.
@@ -112,3 +115,7 @@ type HecToOtelAttrs struct {
 	// Host indicates the mapping of the host field to a specific unified model attribute.
 	Host string `mapstructure:"host"`
 }
+
+type AckRequest struct {
+	Acks []uint64 `json:"acks"`
+}

receiver/splunkhecreceiver/README.md

@@ -51,6 +51,10 @@ The following settings are optional:
 * `hec_metadata_to_otel_attrs/sourcetype` (default = 'com.splunk.sourcetype'): Specifies the mapping of the sourcetype field to a specific unified model attribute.
 * `hec_metadata_to_otel_attrs/index` (default = 'com.splunk.index'): Specifies the mapping of the  index field to a specific unified model attribute.
 * `hec_metadata_to_otel_attrs/host` (default = 'host.name'): Specifies the mapping of the host field to a specific unified model attribute.
+* `ack` (no default): defines the ackextension to use for acknowledging events
+  * `extension` (no default): Specifies the ack extension ID the receiver should use. If left blank, ack is disabled.
+  * `path` (default = '/services/collector/ack'): The path the ack extension will listen on for ack requests, if the extension is enabled.
+
 Example:
 
 ```yaml
@@ -67,6 +71,8 @@ receivers:
       sourcetype: "mysourcetype"
       index: "myindex"
       host: "myhost"
+    ack: 
+      extension: ack/in_memory
 ```
 
 The full list of settings exposed for this receiver are documented [here](./config.go)

receiver/splunkhecreceiver/config.go

@@ -4,6 +4,7 @@
 package splunkhecreceiver // import "github.com/open-telemetry/opentelemetry-collector-contrib/receiver/splunkhecreceiver"
 
 import (
+	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/config/confighttp"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/internal/splunk"
@@ -21,6 +22,9 @@ type Config struct {
 	confighttp.ServerConfig `mapstructure:",squash"` // squash ensures fields are correctly decoded in embedded struct
 
 	splunk.AccessTokenPassthroughConfig `mapstructure:",squash"`
+
+	Ack `mapstructure:"ack"`
+
 	// RawPath for raw data collection, default is '/services/collector/raw'
 	RawPath string `mapstructure:"raw_path"`
 	// Splitting defines the splitting strategy used by the receiver when ingesting raw events. Can be set to "line" or "none". Default is "line".
@@ -30,3 +34,11 @@ type Config struct {
 	// HecToOtelAttrs creates a mapping from HEC metadata to attributes.
 	HecToOtelAttrs splunk.HecToOtelAttrs `mapstructure:"hec_metadata_to_otel_attrs"`
 }
+
+// Ack defines configuration for the ACK functionality of the HEC receiver
+type Ack struct {
+	// Extension defines the extension to use for acking of events. Without specifying an extension, the ACK endpoint won't be exposed
+	Extension *component.ID `mapstructure:"extension"`
+	// Path for Ack API, default is '/services/collector/ack'. Ignored if Extension is not provided.
+	Path string `mapstructure:"path"`
+}

receiver/splunkhecreceiver/config_test.go

@@ -44,6 +44,7 @@ func TestLoadConfig(t *testing.T) {
 				RawPath:    "/foo",
 				Splitting:  SplittingStrategyLine,
 				HealthPath: "/bar",
+				Ack:        Ack{Path: "/services/collector/ack"},
 				HecToOtelAttrs: splunk.HecToOtelAttrs{
 					Source:     "file.name",
 					SourceType: "foobar",
@@ -70,6 +71,7 @@ func TestLoadConfig(t *testing.T) {
 				RawPath:    "/services/collector/raw",
 				Splitting:  SplittingStrategyLine,
 				HealthPath: "/services/collector/health",
+				Ack:        Ack{Path: "/services/collector/ack"},
 				HecToOtelAttrs: splunk.HecToOtelAttrs{
 					Source:     "com.splunk.source",
 					SourceType: "com.splunk.sourcetype",

receiver/splunkhecreceiver/factory.go

@@ -49,7 +49,11 @@ func createDefaultConfig() component.Config {
 		},
 		RawPath:    splunk.DefaultRawPath,
 		HealthPath: splunk.DefaultHealthPath,
-		Splitting:  SplittingStrategyLine,
+		Ack: Ack{
+			Extension: nil,
+			Path:      splunk.DefaultAckPath,
+		},
+		Splitting: SplittingStrategyLine,
 	}
 }
 

receiver/splunkhecreceiver/go.mod

@@ -3,9 +3,11 @@ module github.com/open-telemetry/opentelemetry-collector-contrib/receiver/splunk
 go 1.21
 
 require (
+	github.com/google/uuid v1.6.0
 	github.com/gorilla/mux v1.8.1
 	github.com/json-iterator/go v1.1.12
 	github.com/open-telemetry/opentelemetry-collector-contrib/exporter/splunkhecexporter v0.98.0
+	github.com/open-telemetry/opentelemetry-collector-contrib/extension/ackextension v0.98.0
 	github.com/open-telemetry/opentelemetry-collector-contrib/internal/common v0.98.0
 	github.com/open-telemetry/opentelemetry-collector-contrib/internal/sharedcomponent v0.98.0
 	github.com/open-telemetry/opentelemetry-collector-contrib/internal/splunk v0.98.0
@@ -38,8 +40,8 @@ require (
 	github.com/go-viper/mapstructure/v2 v2.0.0-alpha.1 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
 	github.com/golang/snappy v0.0.4 // indirect
-	github.com/google/uuid v1.6.0 // indirect
 	github.com/hashicorp/go-version v1.6.0 // indirect
+	github.com/hashicorp/golang-lru/v2 v2.0.7 // indirect
 	github.com/klauspost/compress v1.17.8 // indirect
 	github.com/knadh/koanf/maps v0.1.1 // indirect
 	github.com/knadh/koanf/providers/confmap v0.1.0 // indirect
@@ -106,3 +108,5 @@ retract (
 replace github.com/open-telemetry/opentelemetry-collector-contrib/internal/sharedcomponent => ../../internal/sharedcomponent
 
 replace github.com/open-telemetry/opentelemetry-collector-contrib/pkg/golden => ../../pkg/golden
+
+replace github.com/open-telemetry/opentelemetry-collector-contrib/extension/ackextension => ../../extension/ackextension