RabbitMQ exporter implementation (#32051)

**Description:** 
This is the completed implementation of the rabbitmq exporter. 

**Link to tracking Issue:** 

#28891

**Testing:**
- Unit tests
- Happy path with rabbitmq running locally and in the cloud, testing
different configuration options
- Error cases
  - Fail to connect during start-up
  - Invalid credentials
- Connection lost midway through publishing to the queue. The component
attempts reconnecting on the next publish attempt
- Concurrent publishing, both with and without connection issues

**Documentation:** 
Updated README with more configuration options

---------

Co-authored-by: Andrzej Stencel <[email protected]>

.chloggen/rabbitmq-exporter-implementation.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: rabbitmqexporter
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Implements the RabbitMQ exporter
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [28891]
+
+# (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]

exporter/rabbitmqexporter/README.md

@@ -10,7 +10,11 @@
 [development]: https://github.com/open-telemetry/opentelemetry-collector#development
 <!-- end autogenerated section -->
 
-Exports metrics, traces, and logs to [RabbitMQ](https://www.rabbitmq.com/) using the AMQP 0.9.1 protocol
+Exports metrics, traces, and logs to [RabbitMQ](https://www.rabbitmq.com/) using the AMQP 0.9.1 protocol.
+
+Messages are published to the [default exchange](https://www.rabbitmq.com/tutorials/amqp-concepts#exchange-default) direct exchange, but optionally can be published to a different direct exchange. 
+
+This component expects that exchanges, queues, and bindings already exist - they are not currently created by this component.
 
 ## Getting Started
 
@@ -19,16 +23,15 @@ The following settings can be configured:
     - `endpoint` (required, ex = amqp://localhost:5672): Endpoint to connect to RabbitMQ
     - `vhost` (optional): The RabbitMQ [virtual host](https://www.rabbitmq.com/docs/vhosts) to connect to
     - `auth`:
-      - `sasl`: Configuration if using SASL PLAIN authentication
+      - `plain`: Configuration if using SASL PLAIN authentication
         - `username` (required): username for authentication
-        - `password` (required): password for authentication
-    - `tls` (optional): TODO, need to add this
+        - `password`: password for authentication
+    - `tls` (optional): [TLS configuration](https://github.com/open-telemetry/opentelemetry-collector/blob/main/config/configtls/configtls.go#L32)
   - `routing`:
     - `routing_key` (default = otlp_spans for traces, otlp_metrics for metrics, otlp_logs for logs): Routing key used to route exported messages to RabbitMQ consumers
+    - `exchange`: Name of the exchange used to route messages. If omitted, the [default exchange](https://www.rabbitmq.com/tutorials/amqp-concepts#exchange-default) is used which routes to a queue with the same as the routing key. Only [direct exchanges](https://www.rabbitmq.com/tutorials/amqp-concepts#exchange-direct) are currently supported. Note that this component does not handle queue creation or binding.
   - `durable` (default = true): Whether to instruct RabbitMQ to make messages [durable](https://www.rabbitmq.com/docs/queues#durability) by writing to disk
-  - `message_body_encoding`: (default = "otlp_proto"): The encoding of telemetry sent to RabbitMQ
-    - `otlp_proto`: payload is Protobuf serialized from `ExportTraceServiceRequest` if set as a traces exporter or `ExportMetricsServiceRequest` for metrics or `ExportLogsServiceRequest` for logs.
-    - `otlp_json`:  ** EXPERIMENTAL ** payload is JSON serialized from `ExportTraceServiceRequest` if set as a traces exporter or `ExportMetricsServiceRequest` for metrics or `ExportLogsServiceRequest` for logs.
+  - `encoding_extension`: (defaults to OTLP protobuf format): ID of the [encoding extension](https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/main/extension/encoding) to use to marshal data
   - `retry_on_failure`:
     - `enabled` (default = false)
 
@@ -40,7 +43,12 @@ exporters:
       connection:
         endpoint: amqp://localhost:5672
         auth:
-          sasl:
+          plain:
             username: user
             password: pass
+      encoding_extension: otlp_encoding/rabbitmq
+
+extensions:
+  otlp_encoding/rabbitmq:
+    protocol: otlp_json 
 ```

exporter/rabbitmqexporter/config.go

@@ -4,33 +4,42 @@
 package rabbitmqexporter // import "github.com/open-telemetry/opentelemetry-collector-contrib/exporter/rabbitmqexporter"
 
 import (
+	"errors"
+	"time"
+
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/config/configretry"
+	"go.opentelemetry.io/collector/config/configtls"
 )
 
 type Config struct {
 	Connection          ConnectionConfig          `mapstructure:"connection"`
 	Routing             RoutingConfig             `mapstructure:"routing"`
-	MessageBodyEncoding string                    `mapstructure:"message_body_encoding"`
+	EncodingExtensionID *component.ID             `mapstructure:"encoding_extension"`
 	Durable             bool                      `mapstructure:"durable"`
 	RetrySettings       configretry.BackOffConfig `mapstructure:"retry_on_failure"`
 }
 
 type ConnectionConfig struct {
-	Endpoint string     `mapstructure:"endpoint"`
-	VHost    string     `mapstructure:"vhost"`
-	Auth     AuthConfig `mapstructure:"auth"`
+	Endpoint                   string                  `mapstructure:"endpoint"`
+	VHost                      string                  `mapstructure:"vhost"`
+	TLSConfig                  *configtls.ClientConfig `mapstructure:"tls"`
+	Auth                       AuthConfig              `mapstructure:"auth"`
+	ConnectionTimeout          time.Duration           `mapstructure:"connection_timeout"`
+	Heartbeat                  time.Duration           `mapstructure:"heartbeat"`
+	PublishConfirmationTimeout time.Duration           `mapstructure:"publish_confirmation_timeout"`
 }
 
 type RoutingConfig struct {
+	Exchange   string `mapstructure:"exchange"`
 	RoutingKey string `mapstructure:"routing_key"`
 }
 
 type AuthConfig struct {
-	SASL SASLConfig `mapstructure:"sasl"`
+	Plain PlainAuth `mapstructure:"plain"`
 }
 
-type SASLConfig struct {
+type PlainAuth struct {
 	Username string `mapstructure:"username"`
 	Password string `mapstructure:"password"`
 }
@@ -39,5 +48,14 @@ var _ component.Config = (*Config)(nil)
 
 // Validate checks if the exporter configuration is valid
 func (cfg *Config) Validate() error {
+	if cfg.Connection.Endpoint == "" {
+		return errors.New("connection.endpoint is required")
+	}
+
+	// Password-less users are possible so only validate username
+	if cfg.Connection.Auth.Plain.Username == "" {
+		return errors.New("connection.auth.plain.username is required")
+	}
+
 	return nil
 }

exporter/rabbitmqexporter/config_test.go

@@ -4,49 +4,69 @@
 package rabbitmqexporter
 
 import (
+	"errors"
 	"path/filepath"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/config/configretry"
+	"go.opentelemetry.io/collector/config/configtls"
 	"go.opentelemetry.io/collector/confmap/confmaptest"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/exporter/rabbitmqexporter/internal/metadata"
 )
 
+var encodingComponentID = component.NewIDWithName(component.MustNewType("otlp_encoding"), "rabbitmq123")
+
 func TestLoadConfig(t *testing.T) {
 	t.Parallel()
 
 	cm, err := confmaptest.LoadConf(filepath.Join("testdata", "test-config.yaml"))
 	require.NoError(t, err)
 
 	tests := []struct {
-		id       component.ID
-		expected component.Config
+		id           component.ID
+		expected     component.Config
+		errorMessage string
 	}{
 		{
-			id:       component.NewIDWithName(metadata.Type, ""),
-			expected: createDefaultConfig().(*Config),
+			id:           component.NewIDWithName(metadata.Type, "missing_endpoint"),
+			errorMessage: "connection.endpoint is required",
+		},
+		{
+			id:           component.NewIDWithName(metadata.Type, "missing_plainauth_username"),
+			errorMessage: "connection.auth.plain.username is required",
 		},
 		{
 			id: component.NewIDWithName(metadata.Type, "all_fields"),
 			expected: &Config{
 				Connection: ConnectionConfig{
-					Endpoint: "amqp://localhost:5672",
+					Endpoint: "amqps://localhost:5672",
 					VHost:    "vhost1",
 					Auth: AuthConfig{
-						SASL: SASLConfig{
+						Plain: PlainAuth{
 							Username: "user",
 							Password: "pass",
 						},
 					},
+					TLSConfig: &configtls.ClientConfig{
+						Config: configtls.Config{
+							CAFile: "cert123",
+						},
+						Insecure: true,
+					},
+					ConnectionTimeout:          time.Millisecond,
+					Heartbeat:                  time.Millisecond * 2,
+					PublishConfirmationTimeout: time.Millisecond * 3,
 				},
 				Routing: RoutingConfig{
+					Exchange:   "amq.direct",
 					RoutingKey: "custom_routing_key",
 				},
-				MessageBodyEncoding: "otlp_json",
+				EncodingExtensionID: &encodingComponentID,
 				Durable:             false,
 				RetrySettings: configretry.BackOffConfig{
 					Enabled: true,
@@ -60,14 +80,16 @@ func TestLoadConfig(t *testing.T) {
 					Endpoint: "amqp://localhost:5672",
 					VHost:    "",
 					Auth: AuthConfig{
-						SASL: SASLConfig{
+						Plain: PlainAuth{
 							Username: "user",
 							Password: "pass",
 						},
 					},
+					ConnectionTimeout:          defaultConnectionTimeout,
+					Heartbeat:                  defaultConnectionHeartbeat,
+					PublishConfirmationTimeout: defaultPublishConfirmationTimeout,
 				},
-				MessageBodyEncoding: "otlp_proto",
-				Durable:             true,
+				Durable: true,
 				RetrySettings: configretry.BackOffConfig{
 					Enabled: false,
 				},
@@ -84,6 +106,12 @@ func TestLoadConfig(t *testing.T) {
 			require.NoError(t, err)
 			require.NoError(t, component.UnmarshalConfig(sub, cfg))
 
+			if tt.expected == nil {
+				err = errors.Join(err, component.ValidateConfig(cfg))
+				assert.ErrorContains(t, err, tt.errorMessage)
+				return
+			}
+
 			assert.NoError(t, component.ValidateConfig(cfg))
 			assert.Equal(t, tt.expected, cfg)
 		})

exporter/rabbitmqexporter/factory.go

@@ -5,6 +5,8 @@ package rabbitmqexporter // import "github.com/open-telemetry/opentelemetry-coll
 
 import (
 	"context"
+	"crypto/tls"
+	"time"
 
 	"go.opentelemetry.io/collector/component"
 	"go.opentelemetry.io/collector/config/configretry"
@@ -13,10 +15,21 @@ import (
 	"go.opentelemetry.io/collector/exporter/exporterhelper"
 
 	"github.com/open-telemetry/opentelemetry-collector-contrib/exporter/rabbitmqexporter/internal/metadata"
+	"github.com/open-telemetry/opentelemetry-collector-contrib/exporter/rabbitmqexporter/internal/publisher"
 )
 
 const (
-	defaultEncoding = "otlp_proto"
+	defaultConnectionTimeout          = time.Second * 10
+	defaultConnectionHeartbeat        = time.Second * 5
+	defaultPublishConfirmationTimeout = time.Second * 5
+
+	spansRoutingKey   = "otlp_spans"
+	metricsRoutingKey = "otlp_metrics"
+	logsRoutingKey    = "otlp_logs"
+
+	spansConnectionName   = "otel-collector-spans"
+	metricsConnectionName = "otel-collector-metrics"
+	logsConnectionName    = "otel-collector-logs"
 )
 
 func NewFactory() exporter.Factory {
@@ -34,9 +47,13 @@ func createDefaultConfig() component.Config {
 		Enabled: false,
 	}
 	return &Config{
-		MessageBodyEncoding: defaultEncoding,
-		Durable:             true,
-		RetrySettings:       retrySettings,
+		Durable:       true,
+		RetrySettings: retrySettings,
+		Connection: ConnectionConfig{
+			ConnectionTimeout:          defaultConnectionTimeout,
+			Heartbeat:                  defaultConnectionHeartbeat,
+			PublishConfirmationTimeout: defaultPublishConfirmationTimeout,
+		},
 	}
 }
 
@@ -46,13 +63,15 @@ func createTracesExporter(
 	cfg component.Config,
 ) (exporter.Traces, error) {
 	config := cfg.(*Config)
-	r := newRabbitmqExporter(config, set.TelemetrySettings)
+
+	routingKey := getRoutingKeyOrDefault(config, spansRoutingKey)
+	r := newRabbitmqExporter(config, set.TelemetrySettings, newPublisherFactory(set), newTLSFactory(config), routingKey, spansConnectionName)
 
 	return exporterhelper.NewTracesExporter(
 		ctx,
 		set,
 		cfg,
-		r.pushTraces,
+		r.publishTraces,
 		exporterhelper.WithCapabilities(consumer.Capabilities{MutatesData: false}),
 		exporterhelper.WithStart(r.start),
 		exporterhelper.WithShutdown(r.shutdown),
@@ -66,13 +85,15 @@ func createMetricsExporter(
 	cfg component.Config,
 ) (exporter.Metrics, error) {
 	config := (cfg.(*Config))
-	r := newRabbitmqExporter(config, set.TelemetrySettings)
+
+	routingKey := getRoutingKeyOrDefault(config, metricsRoutingKey)
+	r := newRabbitmqExporter(config, set.TelemetrySettings, newPublisherFactory(set), newTLSFactory(config), routingKey, metricsConnectionName)
 
 	return exporterhelper.NewMetricsExporter(
 		ctx,
 		set,
 		cfg,
-		r.pushMetrics,
+		r.publishMetrics,
 		exporterhelper.WithCapabilities(consumer.Capabilities{MutatesData: false}),
 		exporterhelper.WithStart(r.start),
 		exporterhelper.WithShutdown(r.shutdown),
@@ -86,16 +107,41 @@ func createLogsExporter(
 	cfg component.Config,
 ) (exporter.Logs, error) {
 	config := (cfg.(*Config))
-	r := newRabbitmqExporter(config, set.TelemetrySettings)
+
+	routingKey := getRoutingKeyOrDefault(config, logsRoutingKey)
+	r := newRabbitmqExporter(config, set.TelemetrySettings, newPublisherFactory(set), newTLSFactory(config), routingKey, logsConnectionName)
 
 	return exporterhelper.NewLogsExporter(
 		ctx,
 		set,
 		cfg,
-		r.pushLogs,
+		r.publishLogs,
 		exporterhelper.WithCapabilities(consumer.Capabilities{MutatesData: false}),
 		exporterhelper.WithStart(r.start),
 		exporterhelper.WithShutdown(r.shutdown),
 		exporterhelper.WithRetry(config.RetrySettings),
 	)
 }
+
+func getRoutingKeyOrDefault(config *Config, fallback string) string {
+	routingKey := fallback
+	if config.Routing.RoutingKey != "" {
+		routingKey = config.Routing.RoutingKey
+	}
+	return routingKey
+}
+
+func newPublisherFactory(set exporter.CreateSettings) publisherFactory {
+	return func(dialConfig publisher.DialConfig) (publisher.Publisher, error) {
+		return publisher.NewConnection(set.Logger, publisher.NewAmqpClient(), dialConfig)
+	}
+}
+
+func newTLSFactory(config *Config) tlsFactory {
+	if config.Connection.TLSConfig != nil {
+		return config.Connection.TLSConfig.LoadTLSConfig
+	}
+	return func(context.Context) (*tls.Config, error) {
+		return nil, nil
+	}
+}